Search

Background: Studying the physiological growth status of Pinus yunnanensis Franch and Pinus elliottii Engelm. seedlings under different karst fissure thicknesses and rainfall distributions is of great significance for the management, vegetation restoration, and tree species selection in karst rocky desertification areas. In this study, we used a two-factor block experiment and set different rainfall durations, namely reduced rainfall duration (I3d), natural rainfall duration (I6d), and extended rainfall duration (I9d); Different karst small habitats, i.e., stone-free soil (S0), less stone and more soil (S1/4), and half stone and half soil (S1/2), are simulated at these three levels. Analyze the changes in physiological growth and photosynthetic characteristics in two coniferous seedlings under different treatments with different karst thicknesses. Results: The results showed that with the increase of karst thickness, the growth volumes of height and diameter of P. yunnanensis seedlings, the biomass of various organs, and the accumulation of K+, Ca2+, Na+, and Mg2+ showed a significant change pattern of first increasing and then decreasing (P < 0.05); P. elliottii seedlings show a gradually decreasing trend (except for Ca2+). The biomass accumulation of each organ in two coniferous seedlings showed that leaves > stems > roots. The K+, Ca2+, and Mg2+ content in various organs of P. yunnanensis seedlings showed that leaves > roots > stems, while Na+ shows the order of roots > leaves > stems. The accumulation of mineral elements in various organs of P. elliottii seedlings is manifested as roots > stems > leaves and the accumulation of mineral elements in both coniferous seedlings is manifested as Ca2+ > Mg2+ > K+ > Na+. Root length, root volume, root surface area, root diameter, SOD, POD, SP, photosynthetic pigment content, fluorescence parameters, and gas exchange parameters of P. yunnanensis seedlings gradually increase with the increase of karst thickness (except for the 9-day rainfall duration), while those of P. elliottii seedlings gradually decrease. The light saturation point of P. yunnanensis seedlings is highest under the I6dS1/2 treatment, while that of P. elliottii is highest under the I3dS0 treatment. Conclusions: In summary, prolonging rainfall duration has an inhibitory effect on the growth of two types of coniferous seedlings. Increasing karst thickness inhibits the growth of P. elliottii seedlings, and to some extent, promotes the growth and development of P. yunnanensis seedlings. I6dS1/4 and I3dS0 treatments have the best growth effects on P. yunnanensis and P. elliottii seedlings. Therefore, we give priority to P. yunnanensis as the tree species for vegetation restoration or rocky desertification management in karst areas. Our study reveals the role of limestone-filled different karst fissures in mitigating the effects of drought as "containers" for plant growth. These findings help us understand the response of plants to drought stress and provide valuable insights for vegetation restoration in karst environments affected by global climate change. Therefore, further experiments with various karst fissure sizes are necessary to test the universality of the reactions of various plants under different karst fissures. [ABSTRACT FROM AUTHOR]

Introduction: Water and salt conditions are key factors influencing vegetation growth on shell island in the Yellow River Delta. However, the effects of the depth of underground brine on the photosynthetic characteristics and antioxidant system of halophytes remain unclear. Methods: The laboratory simulation experiment was carried out to investigate the effect of the changes of underground brine depth on Suaeda salsa using four levels of groundwater: 0 cm, 15 cm, 30 cm and 45 cm. Results: The results showed that different underground brine depths had significant impacts on the photosynthetic characteristics and antioxidant system of S. salsa, and 0-30 cm underground brine depth was suitable for S. salsa growth. The net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), light utilization efficiency (LUE) and carboxylation efficiency (CE) of S. salsa increased first and then decreased with increasing depth of underground brine. The stomatal limitation value (Ls) and WUE of S. salsa reached the peak value at the groundwater depth of 0 cm, and water use efficiency was reduced by 19.4%, 8.0% and 8.6% at 15 cm, 30 cm, and 45 cm, respectively, compared to the 0 cm treatment. With the deepening of underground brine depth, the value of LUE and CE firstly increased and then decreased, and reached the peak value when the depth was 30 cm. The antioxidant enzyme (SOD, POD and CAT) activities of S. salsa decreased and then increasedwith the increase of underground brine depth. The enzyme activitieswere the lowest when the underground brine depth was 30 cm. As the groundwater depth increased, MDA content decreased and then increased. The highest degree of membrane peroxidation in S. salsa leaves was observed at the depth of 45 cm. Discussion: Our study reveals that the antioxidant capacity of S. salsa wasweakened at the underground brine depth of 45 cm and the growth of S. salsa was inhibited. [ABSTRACT FROM AUTHOR]

To evaluate the effect of Japanese foxtail (Alopecurus japonicus Steud.) at different densities on the photosynthetic physiology of wheat, "Yangmai 16" wheat was cultivated in a field using two sowing rates (150 kg ha−1, conventional seeding rate; 225 kg ha−1, high seeding rate) and with different densities of A. japonicus for two years. A. japonicus affected the physiological characteristics of wheat, such as its leaf photosynthetic rate, fluorescence parameters, Hill reaction activity, Rubisco activity, yield and yield components, to varying degrees. However, the physiological responses of wheat at different seeding rates varied; the effect of A. japonicus on wheat was more severe at the conventional seeding rate than at the high seeding rate. A. japonicus affected wheat leaf morphology and inhibited photosynthetic processes, leading to decreased PSII electron transport, energy metabolism and photosynthate accumulation, ultimately reducing wheat yield. An appropriate increase in the wheat seeding rate could improve specific leaf weight, maintain Rubisco activity, reduce photoinhibition, and alleviate the stress caused by A. japonicus. [ABSTRACT FROM AUTHOR]

The uneven soil fertility made it difficult to implement the recommended nitrogen (N) management practices in the North China Plain (NCP). In order to clarify the effect of N managements in high-fertility soil with a perennial wheat yield of 10,500 kg ha−1 on photosynthetic characteristics, grain yield, N agronomic efficiency (NAE), and water use efficiency (WUE), a trial was conducted from 2022 to 2024. Main plots were N rates of 0 (N1), 150 (N2), 210 (N3), and 270 (N4) kg N ha−1; The sub-plots adopted fertigation (F) and traditional fertilization method (T). The results showed that, compared with T, F increased the intercept rate of photosynthetic effective radiation of canopy, net photosynthetic rate, stomatal conductance, and transpiration rate of flag leaves, as well as the activity of phosphate sucrose synthase and sucrose content. It enhanced dry matter transport and contribution to grain. Under N2, the time required to reach the maximum grain filling rate, duration of grain filling and active grain-filling period of F were improved. Grain yield of N2 was increased by 27.81% and 6.75% compared to N1 and N3, respectively. NAE was improved by 48.63% and 51.47%, and WUE was improved by 20.71% and 9.85%. Therefore, the best effect was achieved by using fertigation and the N rate of 210 kg ha−1 in high-fertility soil. [ABSTRACT FROM AUTHOR]

A two-factor split-plot experiment was carried out in the greenhouse of Linyi agricultural meteorological experimental site using muskmelon 'Xizhoumi 25' as the experimental material. The main area was two planting patterns of single row on ridge (D1) and double row on ridge (D2), and the sub-area was three kinds of melon nodes of 11-12 nodes (R1), 13-14 nodes (R2) and 15-16 nodes (R3), a total of 6 treatments, The plant leaf area and photosynthetic parameters, yield components and fruit quality were measured to explore the effects of different planting patterns and melon retention nodes on photosynthetic characteristics, yield and quality of muskmelon in greenhouse. The results showed that the photosynthetic efficiency of single row planting mode was higher than that of double row planting mode. The fruit diameter, single fruit weight and soluble sugar content of single row planting mode were significantly increased by 2.4%, 11.1% and 9.5%, respectively, compared with double row planting mode (P<0.05). The effect of node location on vegetative growth and reproductive growth of the plant was obvious. The photosynthetic characteristics, fruit length, fruit diameter and single fruit weight of R2 treatment were the best, and the single fruit weight was 9.41% and 14.73% higher than that of R1 and R3, respectively (P<0.05). The effect on fruit quality was extremely significant (P<0.01). The R1 treatment had the highest soluble sugar content, the R2 treatment had the highest sugar-acid ratio, and the R3 treatment had the highest VC and titratable acid content. The interaction between planting pattern and node position had significant effects on leaf area, SPAD, Pn, Ci, Gs and Tr of muskmelon (P<0.05), and the SPAD, Pn, Gs and Tr values of D1R2 combination leaves were the largest before maturity. The interaction had a significant effect on fruit length (P<0.05), and had a very significant effect on fruit diameter, fruit shape index and single fruit weight (P<0.01). Among them, the fruit diameter value of D1R1 combination was the largest, and the fruit shape index of D1R3 was the highest. The fruit length and single fruit weight of the D1R2 combination were the largest, and the average single fruit weight was 28.7% higher than that of other combinations. The interaction had a significant effect on VC content (P<0.05), and had a very significant effect on titratable acid, soluble sugar content and sugar-acid ratio (P<0.01). Of these, the D2R3 combination had the highest VC content, D1R3 had the highest titratable acid content, D1R1 had the highest soluble sugar content and D1R2 had the highest sugar-acid ratio. Under the same planting density and number of functional leaves (22500 plants·ha-1, 25 nodes topping), the three evaluation indexes of yield flavor and taste and VC content of single row planting on ridge and 13-14 nodes interaction (D1R2) mode were the highest, and the comprehensive evaluation of its commodity value was the best. It is recommended that this mode of planting should be applied and generalized in the vertical cultivation of the early spring melons in greenhouses in the north of China. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agronomica Sinica is the property of Crop Science Society of China and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the rapid development of the animal farming industry in China, the large amount of manure has caused a systematic environmental problem, while the demand for high-quality feed continues to increase. The application of dairy cattle slurry to alfalfa fields is a simple and inexpensive solution to the problems above. A repacked soil column study was conducted to investigate the effect of slurry nitrogen (N) on alfalfa biomass, as well as its photosynthetic characteristics. Dairy cattle slurry N or mineral fertilizer N was applied in two dressings at the first cut, with a target amount of 90 kg ha−1. A non-fertilization control (CK), a single mineral fertilizer N (MIN), and a slurry substitution for mineral N fertilizers (with equivalent N rate: FPS, 50% N from dairy cattle slurry; SLU, 100% N from dairy cattle slurry) were used. The results show that the slurry N increased the alfalfa biomass by 16.40–36.36% and the SPAD value by 30.27–61.34% with FPS and SLU treatments, respectively. Compared to the CK treatment, the FPS and SLU treatments meaningfully increased the net photosynthetic rate by 19.97–60.04% and 3.03–89.48%, the stomatal conductance by 10.53–57.14% and 15.38–88.89%, the intercellular CO2 concentration by 5.78–24.92% and 7.21–32.53%, and the transpiration rate by 13.16–103.50% and 16.44–111.19%. More specifically, compared with the CK treatment, the N absorption of the SLU treatment increased by 6.78–12.30%, and the use efficiency increased by 30.98–46.60% in the SLU treatment. Similarly, phosphorus (P) absorption of the SLU treatment increased by 36.73–52.57%, and the use efficiency increased by 30.98–46.60%. Overall, the dairy cattle slurry N was utilized efficiently as mineral N for alfalfa biomass, improved the photosynthetic characteristics of alfalfa leaves, and increased the N and P use efficiency. Our results clarify the optimal amount of dairy cattle slurry to be applied and provide a scientific basis for the use of dairy cattle slurry in agricultural systems. [ABSTRACT FROM AUTHOR]

This study investigates the intricate interactions between strip spacings, water-fertilizer treatments, and the ensuing impact on the physiological attributes and productivity of maize and soybean intercropping systems. Implementing a 2:4 maize-soybean planting configuration within the Ningxia Yellow River irrigation zone, the research scrutinizes the effects of strip spacing (A), irrigation allocation (W), and fertilization intensity (F) on the physiological dynamics, net assimilation rate, leaf area index, and yield metrics of both crops and their integrated systems. It aims to provide comprehensive technical insights for the widespread application of strip intercropping strategies in maize and soybean agroecosystems. Findings reveal nuanced influences, notably the dominant effects of A during critical growth stages of maize (contributing rates of 75.6% to 83.7% during jointing and 52.4% to 81.3% during grain filling) and W primarily impacting the tasseling stage (contributing rates of 91.4% to 92.5%). Moreover, A significantly shapes soybean physiological indices during flowering (contributing rates of 97.9% to 99.3%), while W predominantly impacts pod setting (contributing rate of 70%). Treatment T6 (A2W3F1), characterized by heightened irrigation and reduced fertilizer application, augments maize net assimilation rate (NAR) and leaf area index (LAI) but exhibits an inverse relationship with soybean LAI. The tripartite factors significantly influence both system yield and economic benefits, ranking in order of W>A>F. Notably, all levels of A and W significantly affect maize yield and system productivity, particularly A2>A3>A1 and W3>W2> W1, while the F level shows negligible impact on soybean yield. Contribution analyses underscore A2>A3>A1, W3>W2>W1, and F1>F3> F2 in terms of system economic benefits. Specifically, A2 presents a 25.2% higher benefit compared to A1, W3 demonstrates a 32.3% higher benefit than W1, and F1 exhibits an 11.2% higher benefit over F2. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objective] The study aims to investigate the effects of light quality with different red and blue ratios on the growth, photosynthesis, flavonol accumulation, and antioxidant capacity of Ginkgo biloba, select the light quality suitable for the growth and flavonoid accumulation, and provide a theoretical basis for improving the medicinal value of G. biloba leaves. [Methods] Two-year-old G. biloba seedlings were used, and four light quality treatments with red and blue ratios of 1∶1 (1R1B), 1∶3 (1R3B), 1∶5 (1R5B), and white light (W, control) were set up. The growth, photosynthetic physiology, flavonol content, and antioxidant capacity of G. biloba after 20 days of treatment were analyzed. [Results] Different ratios of red and blue light reduced the biomass of G. biloba leaves, which was not conducive to the growth of plant height and ground diameter, but was conducive to the improvement of leaf length, width, and area and photosynthetic gas exchange parameters.1R5B treatment increased the total chlorophyll content of leaves. 1R1B treatment promoted the accumulation of total leaf biomass. The chlorophyll fluorescence parameters, antioxidant capacity, carotenoid, and total flavonol contents of leaves under 1R3B were the highest. [Conclusion] The appropriate proportion of red and blue light had a significant effect on the growth and photosynthetic characteristics of G. biloba, and significantly increased the content of flavonols and antioxidant capacity. 1R3B red and blue light quality was the most conducive to the accumulation of flavonoids.

Abstract Background Studying the physiological growth status of Pinus yunnanensis Franch and Pinus elliottii Engelm. seedlings under different karst fissure thicknesses and rainfall distributions is of great significance for the management, vegetation restoration, and tree species selection in karst rocky desertification areas. In this study, we used a two-factor block experiment and set different rainfall durations, namely reduced rainfall duration (I3d), natural rainfall duration (I6d), and extended rainfall duration (I9d); Different karst small habitats, i.e., stone-free soil (S0), less stone and more soil (S1/4), and half stone and half soil (S1/2), are simulated at these three levels. Analyze the changes in physiological growth and photosynthetic characteristics in two coniferous seedlings under different treatments with different karst thicknesses. Results The results showed that with the increase of karst thickness, the growth volumes of height and diameter of P. yunnanensis seedlings, the biomass of various organs, and the accumulation of K+, Ca2+, Na+, and Mg2+ showed a significant change pattern of first increasing and then decreasing (P stems > roots. The K+, Ca2+, and Mg2+ content in various organs of P. yunnanensis seedlings showed that leaves > roots > stems, while Na+ shows the order of roots > leaves > stems. The accumulation of mineral elements in various organs of P. elliottii seedlings is manifested as roots > stems > leaves and the accumulation of mineral elements in both coniferous seedlings is manifested as Ca2+ > Mg2+ > K+ > Na+. Root length, root volume, root surface area, root diameter, SOD, POD, SP, photosynthetic pigment content, fluorescence parameters, and gas exchange parameters of P. yunnanensis seedlings gradually increase with the increase of karst thickness (except for the 9-day rainfall duration), while those of P. elliottii seedlings gradually decrease. The light saturation point of P. yunnanensis seedlings is highest under the I6dS1/2 treatment, while that of P. elliottii is highest under the I3dS0 treatment. Conclusions In summary, prolonging rainfall duration has an inhibitory effect on the growth of two types of coniferous seedlings. Increasing karst thickness inhibits the growth of P. elliottii seedlings, and to some extent, promotes the growth and development of P. yunnanensis seedlings. I6dS1/4 and I3dS0 treatments have the best growth effects on P. yunnanensis and P. elliottii seedlings. Therefore, we give priority to P. yunnanensis as the tree species for vegetation restoration or rocky desertification management in karst areas. Our study reveals the role of limestone-filled different karst fissures in mitigating the effects of drought as “containers” for plant growth. These findings help us understand the response of plants to drought stress and provide valuable insights for vegetation restoration in karst environments affected by global climate change. Therefore, further experiments with various karst fissure sizes are necessary to test the universality of the reactions of various plants under different karst fissures.

【Background】 Wheat is the second largest cereal crop after rice in China and is largely grown in arid and semiarid regions in the North. Understanding the impact of water stress on its growth and final yield is important to improve its water use efficiency and safeguard wheat production. We studied this in a field experiment. 【Method】 The experiment was conducted at Wuwei of Gansu province, using the varieties Longchun 41 and Yongliang No.4 as the model plants. This paper aimed to elucidate how water stress imposed in the jointing and grain-filling stages influence growth, physiology and yields of the crops. The control was sufficient irrigation (CK). There were four deficit irrigation treatments: irrigating 65% of water in the CK during both jointing and grain-filling stages (W1), 80% during the joint stage and 65% during the grouting stage (W2), 65% during the jointing stage and 80% during the grain-filling stage (W3), 80% during both jointing and grain-filling stages (W4). In each treatment, we measured growth indexes, grain yield, leaf photosynthetic traits and chlorophyll fluorescence kinetic traits. 【Result】 Water stress during the jointing and grain-filling stages significantly reduced plant height, leaf area index, dry matter accumulation, net photosynthetic rate, transpiration rate, and photosynthetic electron transport rate. Sufficient irrigation during the tasseling stage can restore the leaf area index (LAI) of the Longchun 41 variety, positively influencing SPAD values, photosynthetic electron transfer, and transpiration. Increasing water deficit led to a reduction in grain yield. On average, the yield of Longchun No.41 was higher than that of Yongliang No.4. The yield of Longchun No.41 in W4 was not significantly different from that in CK. 【Conclusion】 Considering water saving and grain yield, the optimal irrigation and cultivation for spring wheat in the studied region is to grow the Longchun No.41 variety and irrigate 80% of water used in sufficient irrigation during both the jointing and grain-filling stages.

Abstract [Objective] The study aims to explore the effects of compound fungi inoculant application on the growth, root morphology, and photosynthetic characteristics of Chinese flowering cabbage seedlings, and provide a theoretical basis for the application of compound fungi inoculant to alleviate the obstacle of continuous cropping of Chinese flowering cabbage. [Methods] The Chinese flowering cabbage variety ‘Jianye- 70’, with which microbial agents and soil had been continuously cropped for 9 years, were used in pot experiments. Four treatments were set up: No compound microbial agents (control), foliar spraying, soil spraying, and foliar spraying plus soil spraying. The plant growth indicators, root system configuration, and leaf photosynthetic characteristics were observed after sowing for 30 days. [Results] Every application method could increase growth indicators, root system conformation, leaf photosynthetic characteristics net photosynthetic rate (Pn), actual photochemical efficiency (ΦPSⅡ ), and photochemical quenching coefficient (qp) etc., as well as decrease transpiration rate (Tr), intercellular carbon dioxide concentration (Ci), and non photochemical quenching coefficient (NPQ) etc. Among the application methods, foliar spraying had the best effect. Its above-ground and underground dry weight and root length were significantly increased by 128.57%, 85.71%, and 91.81%. Pn, qp, and ΦPSⅡ were significantly increased by 24.55%, 22.68%, and 23.93%, while Tr, Ci, and NPQ were significantly decreased by 72.73%, 20.01%, and 39.78%, respectively. [Conclusion] Foliar spraying of compound fungi can effectively promote the growth of continuous cropping cabbage seedlings, improve root configuration, enhance plant photosynthetic efficiency, which is the best way of compound fungi application

Abstract [Objective] The study aims to investigate the effects of different shading levels on the photosynthetic characteristics and leaf anatomical structure of wild plant Ranunculus ternatus Thunb. and provide a theoretical basis for the in-depth understanding of its shading tolerance and large-scale planting. [Methods] This experiment adopts the method of controlling variables with R. ternatus Thunb. as materials. Five shading treatments full light (CK), 30% shading (T1), 50% shading (T2), 70% shading (T3), and 90% shading (T4), were applied. [Results] (1) With the increase of shading, the leaf area reached the maximum under T3 environment. Plant height and stem diameter were decreased with the decrease of light. (2) With the increase of shading, the leaf apparent quantum efficiency (AQE) of R. ternatus was first increased and then decreased, and was lower than other treatments under T4 treatment. Light saturation point (LSP), light compensation point (LCP), dark respiration rate (Rd), and maximum net photosynthetic rate (Pn,max) were decreased gradually. Maximum fluorescence (Fm), variable fluorescence (Fv), maximized chemical efficiency (Fv/Fm), and PSⅡ potential activity (Fv/Fo) were increased first and then decreased, while the electron ratio of heat dissipation (φDo) and the initial fluorescence (Fo) was decreased first and then increased. (3) With the increase of shading, the stomatal density of R. ternatus was first decreased and then increased, and reached the minimum value at T3 treatment. The thickness of the upper and lower epidermis and the thickness of the sponge gradually were decreased, the tissue structure compactness (CTR) was decreased first and then increased, and the tissue structure porosity (SR) was first increased and then decreased. (4) Leaf palisade tissue, sponge tissue, leaf thickness, and upper, and lower epidermal thickness were positively correlated with Rd. Sponge tissue thickness (ST), CTR, and SR were positively correlated with Pn,max. P/S and SR were positively correlated with AQE. However, sponge tissue thickness (ST) and SR were negatively correlated with Fo. [Conclusion] R. ternatus can improve its shading tolerance by reducing photosynthetic rates and changing leaf structures; it grows well in full light and adapts to 30%-70% shading environment.

Far red photon flux accelerates photosynthetic electron transfer rates through photosynthetic pigments, influencing various biological processes. In this study, we investigated the impact of differing red and far-red light ratios on plant growth using LED lamps with different wavelengths and Ca1.8Mg1.2Al2Ge3O12:0.03Cr3+ phosphor materials. The control group (CK) consisted of a plant growth special lamp with 450 nm blue light + 650 nm red light. Four treatments were established: F1 (650 nm red light), F2 (CK + 730 nm far-red light in a 3:2 ratio), F3 (650 nm red light + 730 nm far-red light in a 3:2 ratio), and F4 (CK + phosphorconverted far-red LED in a 3:2 ratio). The study assessed changes in red and farred light ratios and their impact on the growth morphology, photosynthetic characteristics, fluorescence characteristics, stomatal status, and nutritional quality of cream lettuce. The results revealed that the F3 light treatment exhibited superior growth characteristics and quality compared to the CK treatment. Notably, leaf area, aboveground fresh weight, vitamin C content, and total soluble sugar significantly increased. Additionally, the addition of far-red light resulted in an increase in stomatal density and size, and the F3 treatments were accompanied by increases in net photosynthetic rate (Pn), transpiration rate (Tr), intercellular CO2 concentration (Ci), and stomatal conductance (Gs). The results demonstrated that the F3 treatment, with its optimal red-to-far-red light ratio, promoted plant growth and photosynthetic characteristics. This indicates its suitability for supplementing artificial light sources in plant factories and greenhouses. [ABSTRACT FROM AUTHOR]

Relevant indicators were determined at different canopy heights(lower, middle, and upper)to analyze the vertical gradient for variations in the hydraulic architecture and photosynthetic characteristics and the relationships between them in a 7-year old Chinese fir, in Baisha State-owned Forest Farm of Minhou, Fujian Province. Significant differences(P＜0.05)were found in the hydraulic architecture and photosynthetic characteristics at different canopy heights. Hydraulic conductivity, specific conductivity, leaf-specific conductivity, water potential, and sapwood area generally decreased with increasing canopy height, with upper canopy(9 m)showing reductions of 50.2%, 35.5%, 42.6%, 23.7%, and 24.4%, respectively, compared to the lower canopy(4 m, P＜0.05).The Huber value initially decreased and then increased; however, the difference was not statistically significant. The net photosynthetic rate, stomatal conductance, transpiration rate, instantaneous water use efficiency, and stomatal limitation were significantly higher in the lower canopy than in the upper canopy, whereas the intercellular CO2 concentration was significantly higher in the upper canopy(P＜0.05).Compared with that in the lower canopy, the net photosynthetic rate in the middle and upper canopy leaves decreased by 24.4%and 32.9%, stomatal conductance decreased by 13.9%and 21.0%, transpiration rate decreased by 6.4%and 12.1%, instantaneous water-use efficiency decreased by 19.7%and 23.1%, and stomatal limitation decreased by 6.1%and 12.1%, respectively, whereas the intercellular CO2 concentration increased by 3.5%and 6.5%, respectively. Correlation analysis revealed significant positive relationships between hydraulic conductivity and both the net photosynthetic rate and stomatal conductance(P＜0.05).Specific conductivity was positively correlated with net photosynthetic rate, instantaneous water use efficiency, and stomatal limitation and negatively correlated with intercellular CO2 concentration(P＜0.01).Leaf-specific conductivity showed significant positive correlations with both stomatal conductance and the net photosynthetic rate(P＜0.01).Water potential was positively correlated with the net photosynthetic rate(P＜0.01), and sapwood area was positively correlated with stomatal conductance(P＜0.05).These findings suggest that increased tree height in Chinese fir leads to longer water transport paths, increased resistance and gravity, reduced hydraulic conductivity, closed stomata, and decreased photosynthetic efficiency to minimize water loss, indicating height-related hydraulic limitations. has context menu [ABSTRACT FROM AUTHOR]

[Objectives] his study aimed to explore the effects of drought stress on morphological changes, photosynthetic characteristics and other physiological indexes of ginger at seedling stage, and to provide reference for the study of drought tolerance mechanism and the selection of drought-tolerant varieties of ginger. [Methods] Five main varietie (‘Shandongdajiang'‘Fengtoujiang'‘Zhugenjiang'‘Luopingxiaohuangjiang'and‘Guizhouxiaohuangjiang') were selected as test materials from the main ginger producing areas of North China, Central China and Southwest China. Drought stress was simulated by 250 g·L-1 PEG-6000 solution, normal water treatment (CK) and drought treatment (DS) was set to determine the growth and physiological indexes such as leaf moisture content, leaf water potential, photosynthesis, stomatal phenotype, chlorophyll content and other growth and physiological indexes of different varieties of ginger under different treatments at 15 days, and the lignin deposition of ginger stems was observed by paraffin sectioning method. [Results] Compared with CK, the leaves of various ginger varieties had different degrees of curly yellowness at 15 days of drought treatment. The free water content (FWC), relative water content (RWC) and total water content (TWC) of leaves decreased significantly, the content of bound water (BWC) of ‘Shandongdajiang' increased, and the BWC content of the remaining four varieties decreased significantly. The water potential of the leaves of various varieties of ginger decreased significantly, and the ‘Fengtoujiang' decreased the most. In addition, the net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), transpiration rate (Tr) of leaves decreased, the length and width of the stomata decreased, and the length and width of guard cells did not change significantly. Among the five varieties, the photosynthetic index of ‘Luopingxiaohuangjiang' was the most affected, and the stomatal conductance and transpiration rate decreased by 100% and 93.84%, respectively. The contents of chlorophyll a (Chla), chlorophyll b (Chlb) and total chlorophyll a+b (Chla+b) decreased but not significantly, while the content of carotenoid (Car) increased in‘Shandongdajiang 'but not significantly, and decreased significantly in the other four varieties. After drought treatment, the amount of stem lignin deposition increased in‘Shandongdajiang 'and‘ Luopingxiaohuangjiang'. [Conclusions] Drought stress affected the growth and development of ginger seedlings, and there were differences in drought tolerance among different ginger varieties. The drought tolerance of the five ginger varieties was ranked from strong to weak as follows: ‘Shandongdajiang'‘Fengtoujiang'‘Guizhouxiaohuangjiang'‘Zhugenjiang'‘Luopingxiaohuangjiang'.‘Shandongdajiang'had strong drought tolerance, which could be used for further analysis of the molecular mechanism of drought resistance and creation of drought resistance breeding high-quality germplasm materials. [ABSTRACT FROM AUTHOR]

Utilizing new irrigation techniques to introduce cultivars into paddy fields experiencing water scarcity is one way to combat water shortage and increase water productivity. To this end, this experiment was conducted as a strip plot in a randomized complete block design with three independent replications over two years (2016 and 2017) at the Rice Research Institute of Iran, Amol, Iran. Ten rice genotypes (V1 to V10) were subjected to three types of irrigation systems, including conventional Flood Irrigation (FI) and Alternate Wetting and Drying (AWD) at 10 (AWD10) and 20 (AWD20) cm below the soil surface. These results demonstrate that AWD10 and AWD20 methods reduced water consumption by 20 and 17%, respectively, compared to the conventional methods. This decreased water usage resulted in 1.4 and 0.2% yield losses compared to the conventional flood irrigation system. Moreover, milling recovery in flood irrigation (68.7%) was lower than AWD10 and AWD20 methods (69.6 and 69.8%, respectively). In conclusion, Neda, Shiroodi, and 8611 rice genotypes showed a better response to AWD irrigation, and may be considered as suitable genotypes for increasing water productivity in paddy fields. [ABSTRACT FROM AUTHOR]

To reveal the causes of photosynthetic characteristics of Yulania denudata with variegated leaf, the green leaves, variegated leaves and yellow leaves of Y. denudata with variegated leaf were used as experimental materials. The anatomical structure and photosynthetic characteristics in three types of leaves were compared from the aspects of photosynthetic pigment content, leaf anatomical structure and light response curve. The results were as follows: (1) The yellow leaf spots of Y. denudata with variegated leaf were chlorophyll-type leaf spots formed by the decrease of chlorophyll content due to the abnormal structure of chloroplasts. (2) The structure of thylakoids in the yellow region of Y. denudata with variegated leaf was abnormal, and ATP synthesis was blocked, which hindered the progress of photosynthesis. (3) The anatomical structure showed that the palisade tissue of the green leaf was developed, the chloroplast integrity and pigment content were higher than those of the variegated leaf and the yellow leaf, and the net photosynthetic rate was higher. (4) There were significant differences in the maximum net photosynthetic rate and light saturation point between the green leaf and the variegated leaf, and the green leaf could withstand a wider range of bright light than the variegated leaf. This study further elucidates that the chloroplast structure of Y. denudata with variegated leaf affects its photosynthetic characteristics, and provides a reference for the breeding of excellent germplasm of Y. denudata with variegated leaf. [ABSTRACT FROM AUTHOR]

Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objective] To study the photosynthetic characteristics of Citrus aurantium in summer. [Method] By using Li-6400 portable photosynthesis system, the net photosynthetic rate (Pn) of leaves in different positions, diurnal variation of photosynthesis, light response curve and CO2 response curve of Citrus aurantium were measured. [Result] There were certain differences in Pn of leaves in different directions and parts. The diurnal variation of Pn of Citrus aurantium in summer showed a double-peak curve with a “nap” phenomenon, and the photosynthetic peaks appeared at 10:00 and 14:30, respectively. The diurnal variation of stomatal conductance was similar to that of Pn. From the light response curve, it could be seen that Citrus aurantium had a high saturation point and a light intensity of 0-2 000 μmol/ (m²·s), the Pn continued to increase, reaching a maximum of 13.44 μmol/ (m²·s), with a light compensation point of 28.33 μmol/ (m²·s), the apparent quantum efficiency was 0.036. From CO2 response curve, the CO2 saturation point and CO2 compensation point were about 1 500 μmol/mol and 60.65 μmol/mol, respectively, and the carboxylation efficiency was 0.079. The results of correlation and regression analysis showed that in summer Pn of Citrus aurantium was closely associated with physiological and ecological factors, such as stomatal conductance, relative humidity, intercelluar CO2 concentration, transpiration rate, vapor pressure deficienc. [Conclusion] Citrus aurantium was a heliophile C3 plant and it had a strong ability to adapt and utilize low light and strong assimilation ability to CO2. And under the high temperature and low air relative humidity in summer, the photosynthesis of Citrus aurantium was affected by various physiological and ecological factors. In this period, the photosynthetic active radiation was not the key factor affecting Pn, and the air relative humidity was significantly positively correlated with Pn. Therefore, environmental selection or cultivation measures to increase the air relative humidity could mitigate the midday depression of photosynthesis in summer and improved the photosynthetic efficiency of Citrus aurantium. [ABSTRACT FROM AUTHOR]

Alfalfa mosaic virus (AMV) is one of the most widely distributed viruses; it often exhibits combined infection with white clover mosaic virus (WCMV). Even so, little is known about the effects of co-infection with AMV and WCMV on plants. To determine whether there is a synergistic effect of AMV and WCMV co-infection, virus co-infection was studied by electron microscopy, the double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA), and real-time fluorescence quantitative PCR (RT-qPCR) of AMV and WCMV co-infection in Nicotiana benthamiana. Meanwhile, measurements were carried out on the photosynthetic pigments, photosynthetic gas exchange parameters, and chlorophyll fluorescence parameters. The results showed that the most severe disease development was induced by AMV and WCMV co-infection, and the disease grade was scale 7. N. benthamiana leaves induced mottled yellow-green alternating patterns, leaf wrinkling, and chlorosis, and chloroplasts were observed to be on the verge of disintegration. The relative accumulation of AMV CP and WCMV CP was significantly increased by 15.44-fold and 10.04-fold upon co-infection compared to that with AMV and WCMV single infection at 21 dpi. In addition, chlorophyll a, chlorophyll b, total chlorophyll, the net photosynthetic rate, the water use efficiency, the apparent electron transport rate, the PSII maximum photochemical efficiency, the actual photochemical quantum yield, and photochemical quenching were significantly reduced in leaves co-infected with AMV and WCMV compared to AMV- or WCMV-infected leaves and CK. On the contrary, the carotenoid content, transpiration rate, stomatal conductance, intercellular CO2 concentration, minimal fluorescence value, and non-photochemical quenching were significantly increased. These findings suggest that there was a synergistic effect between AMV and WCMV, and AMV and WCMV co-infection severely impacted the normal function of photosynthesis in N. benthamiana. [ABSTRACT FROM AUTHOR]

The fodder soybean (Glycine max) is an excellent leguminous forage with a high protein content and hay yield, cultivated comprehensively in alpine regions, but seasonal drought in northern regions severely impacts the growth of seedlings. Melatonin (MT) and strigolactone (SL) are critical in relieving the restraint of plant growth in water-deficient environments, but the mechanisms of MT- and SL-mediated drought resistance in fodder soybean needs to be explored. This study mainly investigated the potential morphophysiological mechanism of MT and SL treatments in protecting fodder soybean from drought stress. The fodder soybean 'Gongnong 535' was treated with 100 µM MT or 1 µM SL under normal, moderate, and severe water deficit conditions. The results showed that MT and SL treatments enhanced the plant growth parameters and stomatal aperture under drought stress. Moreover, the observed reductions in superoxide ion (O2.-), malondialdehyde (MDA), and relative electrical conductivity (REC), along with enhancements in the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), as well as higher levels of ascorbate (AsA), glutathione (GSH), soluble sugar (SS), soluble protein (SP), and free proline (Pro), indicated that MT and SL application effectively alleviated the oxidative damage and prevented the cell membrane disruption caused by drought stress. Additionally, MT and SL treatments improved photosynthesis and growth in fodder soybean seedlings under water stress by adjusting chlorophyll pigments, gas exchange indexes, and chlorophyll fluorescence parameters, as well as endogenous hormone levels. Simultaneously, MT and SL influenced the expression of genes associated with photosynthesis and antioxidant defenses, as well as phytohormone concentrations. Notably, the protective effect of the SL treatment was superior to that of MT in water-deficient conditions. This study contributes to further understanding the defensive mechanism of MT and SL against drought stress. [ABSTRACT FROM AUTHOR]

In Northeast China's black soil rice cropping area, nitrogen (N) application is lower than in the south, yet excessive N fertilizer use persists, particularly in base fertilizers. This study aimed to assess the impact of reduced N and increased planting density on rice yields and photosynthetic matter production. From 2019 to 2020, a field split-plot experiment was conducted with two N rates (conventional N, CN: 120 kg ha−1 and reduced basal N, RN: 108 kg ha−1) and two planting densities (D1: 33.3 × 104 hills ha−1 and D2: 27.8 × 104 hills ha−1) using the rice varieties Kongyu131 (KY131) and Kendao24 (KD24). The results showed that RN increased the effective panicle formation rate but decreased the tiller numbers, dry matter accumulation, stems/sheaths transport capacity, leaf photosynthetic capacity, and yield by 2.67% compared to CN. D1 significantly boosted the dry matter accumulation, stems/sheaths transport, effective panicles, grains per square meter, and yield by 8.26% compared to D2. Interaction analysis revealed that RN under D2 conditions reduced the effective panicle percentage, harvest index, filled grain number, leaf area index (LAI), crop growth rate (CGR), and net assimilation rate (NAR) but increased the seed setting rate and 1000-grain weight. Under D1, RN reduced the LAI, CGR, and NAR at the tillering and heading stages but increased the NAR post-heading. Compared to CND2, RND1 increased the biomass, stems/sheaths transport, LAI, CGR, NAR, seed setting rate, 1000-grain weight, panicle numbers, and filled grains per square meter, compensating for the lower harvest index and effective panicle rate, achieving a 5.36% yield increase. KD24 outperformed KY131 in yield improvement. In summary, using 108 kg ha−1 with a planting density of 33.3 × 104 hills ha−1 promotes tillering, enhances photosynthetic substance production stems/sheaths dry matter transport, and increases rice yields. [ABSTRACT FROM AUTHOR]

To address water scarcity and soil damage in the Hexi Oasis irrigation area of China, a study was conducted on regulating water and nitrogen levels for soybean growth under film drip irrigation over two growing seasons (2020 and 2021). Two irrigation levels were tested: mild deficit (W1, 60–70% of field water capacity, FC) and full irrigation (W2, 70–80% of FC), along with three nitrogen levels: low (N1, 60 kg·ha−1), medium (N2, 120 kg·ha−1), and high (N3, 180 kg·ha−1). The control treatment was no nitrogen with full irrigation (W2N0), totaling seven treatments. Results showed that during both growing seasons, soybean plant height reached its peak at the tympanic ripening stage, while the leaf area index (LAI), net photosynthesis rate (Pn), and transpiration rate (Tr) decreased at the tympanic ripening stage. The highest values for the plant height, LAI, Pn, Tr, yield, and the cost–benefit ratio were observed under the W2N2 treatment, significantly outperforming the W2N0 in all aspects (p < 0.05). Over the two-year period, the plant height and LAI were notably higher by 22.86% and 7.09%, respectively, in the W2N2 treatment compared to the W1N1. Full irrigation under N1 and N2 conditions resulted in an enhanced soybean Pn and Tr. However, under N3 conditions, a deficit-tuned irrigation treatment led to a 15.71% increase in the Pn and a 13.34% increase in the Tr on a two-year average. The W2N2 treatment had the highest yield, with a significant 4.93% increase over the W1N3 treatment on a two-year average. The highest rate of change in yield was observed in W1. The two-year cost–benefit ratio and unilateral water benefit reached their peak values in W2N2 and W1N2, respectively. Water use efficiency (WUE) was lower in N1 but significantly increased by 21.83% on a two-year average in W1N3 compared to W1N2. Additionally, W1 had a 14.21% higher WUE than W2 over two years. N3 had the lowest partial factor productivity of nitrogen, which increased by 17.78% on a two-year average in W2N1 compared to W1N1. All nine indicators related to yield formation and water–nitrogen use efficiency showed a positive correlation (p < 0.05) in this study. The highest composite scores were achieved with the W2N2 treatment in both years using the entropy weight and TOPSIS method. Overall, the W2N2 treatment provides a water and nitrogen combination that enhances soybean water and fertilizer efficiency, making it a promising option for high-yield soybean cultivation with water and nitrogen conservation in the Hexi Oasis irrigation area of China. This study offers valuable insights for achieving efficient soybean production while saving water and reducing nitrogen use. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dairy slurry could be a significant source of nitrogen (N) for plants, but mismanagement can lead to atmospheric ammonia losses or nitrate leaching into groundwater. To make the use of dairy slurry efficient and reasonable, the loss of N pollution to the environment should be reduced. We used repacked lysimeters to comprehensively determine ammonia emission and N leaching losses in an alfalfa–soil system. The application of dairy slurry had no significant effect on alfalfa yield at the same rate of N application in comparison to chemical fertilizer, and adding humic acids significantly increased yield by about 12%. However, the application of dairy slurry increased the ammonia emission rate significantly, leading to an increase in the cumulative amount of ammonia emission, while the addition of humic acids reduced the ammonia emissions by 11%. Chemical fertilizer and dairy slurry application significantly increased nitrate leaching compared to the control treatment, while the addition of humic acids can significantly reduce ammonium N leaching. Dairy slurry was proven to be as effective as chemical N fertilizer in achieving the optimum biomass, and adding humic acids can significantly reduce N loss to the atmosphere and groundwater. This study showed the possibility of replacing chemical fertilizer with dairy slurry in alfalfa production and the advantages of humic acids' addition to alfalfa to maintain production yield and improve environmental friendliness. [ABSTRACT FROM AUTHOR]

Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, four light models including rectangular hyperbola model, non-rectangular hyperbolic model, modified rectangular hyperbolic model and exponential model were jointly adopted to evaluate the photosynthetic parameters and light response fitting curves of six Callicarpa Linn. species in southern subtropical regions. By comparison of the light saturation point (LSP), light compensation point (LCP), maximum net photosynthetic rate (P), dark respiration rate (R) and apparent quantum efficiency (AQE), as well as the coefficient of determination (R), root mean square error (RMSE) and mean absolute error (MAE) derived from the four models, the most suitable light response models for these six plants were obtained. The results demonstrated that the modified rectangular hyperbolic model performed the best fitting ability for the photosynthetic study of the six Callicarpa species, and the highest light utilization ability under both strong and weak light belonged to C. formosana, and the highest photosynthetic efficiency was found in C. japonica var. Luxurians. In summary, these six Callicarpa species showed both interspecific variability and interspecific similarity in light utilization capacity, and the four light response models differed greatly in the calculation of the photosynthetic potential, however, there was consistency in the model's goodness-of-fit and fitting accuracy. [ABSTRACT FROM AUTHOR]

Solanum lycopersicum L. can be classified into low Cd-accumulating and high Cd-accumulating types based on their accumulation characteristics of cadmium (Cd). There are many common S. lycopersicum varieties available in the market, but their specific Cd tolerance and enrichment abilities are not well understood. This article uses two S. lycopersicum cultivars, Yellow Cherry and Yellow Pearl, as experimental materials. The experimental method of soil pot planting was adopted, and Cd concentrations in the soil were added at 0, 0.6, 1.5, 2.5, 5, and 10 mg/kg. The changes in Cd content, biomass, photosynthetic pigment content, and photosynthetic parameters of the two S. lycopersicum cultivars were analyzed to screen for low-accumulation S. lycopersicum cultivars. The results showed that S. lycopersicum are Cd-sensitive plants. The Cd accumulation, photosynthetic parameters, and other basic indicators of Yellow Cherry basically showed significant differences when the soil Cd concentration was 0.6 mg/kg, and the biomass showed significant differences when the soil Cd concentration was 1.5 mg/kg. Except for the Cd accumulation in the roots and leaves of Yellow Pearl, which showed significant differences at a soil Cd concentration of 0.6 mg/kg, the other indicators basically showed significant differences when the soil Cd concentration was 1.5 mg/kg. When the soil Cd concentration was 0.6 mg/kg, the Cd accumulation in the fruit of Yellow Pearl was 0.04 mg/kg, making it a low-accumulation S. lycopersicum variety suitable for promoting cultivation in Cd-contaminated soil at 0.6 mg/kg. In conclusion, the Cd accumulation in the fruit of Yellow Pearl is significantly lower than that of Yellow Cherry and even below the Cd limit value for fresh vegetables specified in GB2762-2017. Therefore, Yellow Pearl can be grown as edible crops in soils with Cd concentrations ≤0.6 mg/kg. Furthermore, Yellow Cherry demonstrate strong Cd tolerance and can be used for the remediation of Cd-contaminated soils. [ABSTRACT FROM AUTHOR]

【Objective】To investigate the effects of inoculation with Trichoderma harzianum and Bacillus subtilis on the growth, photosynthetic characteristics, and antioxidant enzyme activity of Malus micromalus Makino seedlings.【Methods】A pot experiment was conducted on Malus micromalus Makino seedlings as experimental subjects, with four treatments, application of sterile water (CK), inoculation of T. harzianum suspension (TH), inoculation of B. subtilis suspension (BS), and mixed inoculation of T. harzianum suspension and B. subtilis suspension (TB). The effects of growth indicators, leaf SPAD values, gas exchange parameters, antioxidant enzyme activity, and malondialdehyde (MDA) content of Malus micromalus Makino seedlings were analyzed at 30 and 60 days after inoculation.【Results】TH, BS and TB treatments all promoted the growth, photosynthesis, and antioxidant enzyme activity of Malus micromalus Makino seedlings, with TB treatment showing the best effect. Compared with CK, after 30 and 60 days of inoculation, TB treatment significantly increased seedling plant height, stem diameter, number of leaves, aboveground dry weight, root dry weight, and root length by 16.52%, 7.43%, 23.81%, 13.71%, 21.44%, 31.06% and 16.27%, 16.54%, 18.06%, 9.36%, 15.41%, 24.18%, respectively (P<0.05); the SPAD values of seedling leaves significantly increased by 13.38% and 10.85% (P<0.05); the net photosynthetic rate, stomatal conductance, transpiration rate, and intercellular CO2 concentration of seedling leaves significantly increased by 14.08%, 14.08%, 31.03%, 9.84%and 11.88%, 27.13%, 14.95%, 10.92%, respectively (P<0.05); the activities of peroxidase activity, phenylalanine ammonia-lyase activity, superoxide dismutase activity, catalase activity, and polyphenol oxidase activity significantly increased by 20.93%, 30.10%, 42.00%, 21.52%, 23.71%, and 21.21%, 22.52%, 35.39%, 18.18%, and 18.11%, respectively (P<0.05); after 60 days of inoculation, the MDA content significantly decreased by 9.54% (P<0.05).【Conclusion】Mixed inoculation of Trichoderma harzianum and Bacillus subtilis can effectively promote the growth of Malus micromalus Makino seedlings, increase chlorophyll content and photosynthetic rate, and enhance antioxidant enzyme activity. [ABSTRACT FROM AUTHOR]

The problem of poor water and fertilizer retention in sandy soils can lead to physiological growth restriction and yield and quality decline in apples. Sodium carboxymethyl cellulose (CMC) formula can improve the soil structure and increase the water- and fertilizer-holding capacity of the soil, and Biogenic Stimulant (BS) can improve the drought stress resistance of crops and promote the physiological growth of crops. Considering that CMC and BS may improve the physiological characteristics of sandy soil apples, in this study, CMC was coupled with BS in sandy apples, and the effects on the physiological characteristics, yield, and quality of apples were systematically investigated. The results showed that CMC and BS could increase leaf N, P, and K content, with the greatest increases seen in the Y2C2 treatment (9.28, 0.61, and 0.56 g kg−1, respectively) compared with the CK treatment. The SPAD values of leaves following the coupled CMC and BS treatment compared to the CK treatment were elevated in the range of 4.47–24.29% at the flowering and fruiting stage, 2.84–26.50% at fruit expansion stage, and 6.64–19.41% at maturation stage. In the light response data of different treatments, the maximum net photosynthetic rate occurred in the Y2C2 treatment, and the net photosynthetic rate, transpiration rate, and stomatal conductance were all the highest in the Y2C2 treatment during the fruit expansion stage, with the net photosynthetic rate being higher than that of the CK treatment by 5.09 µmol m−2 s−1. The combination treatments of CMC and BS increased apple yield by 10.69 to 27.62% as compared to the CK treatment, and also increased soluble reducing sugar, soluble solids, and VC and reduced the titratable acid content. There was no correlation between the SPAD value during fruit expansion (p > 0.05) and the other physiological indexes (p < 0.05). Through the established functional relationship between the application rate of CMC and BS and apple yield, the recommended BS application rate of 27 kg ha−1 and CMC application rate of 20.625 kg ha−1 could yield up to 43,357.8 kg ha−1. [ABSTRACT FROM AUTHOR]

[Objectives] The paper aimed to create a new autotetraploid material with good quality. [Methods] The cotyledon growth point of the diploid Brassica campestris LCX019 seedlings was dripped with 2 g-L colchicine solution, the autotetraploid plants were identified by morphological, anatomical, cytological and flow cytometry methods, and the agronomic and quality characteristics of diploid and tetraploid plants were analyzed and compared. [Results] The results of morphology and anatomy showed that the plant type, leaf, flower, seed pod and bolt of the autotetraploid campestris showed "gigantic" characteristics, the stomatal diameter became larger and the stomatal density decreased. The size of pollen grains was larger than diploid, and the shape of pollen grains was rugby ball or irregular. The results of cytology showed that the number of chromosomes in the root tip of tetraploid was about twice that of diploid. Flow cytometry analysis showed that the DNA fluorescence intensity of tetraploid was about twice that of diploid. The contents of soluble sugar, organic acid and cellulose in tetraploid B. campestris significantly increased by 76.17%, 13.71% and 80.34%, while the contents of chlorophyll and nitrate nitrogen significantly decreased by 25.01% and 45.10%, respectively, there was no significant change in soluble protein content. By analyzing the light response curve and photosynthetic characteristics of diploid and tetraploid plants, it was found that LCX019 had stronger ability to utilize weak light than diploid plants. [Conclusions] The new tetraploid material with high quality was obtained, which would provide new germplasm resources for the breeding of flowering Chinese cabbage. [ABSTRACT FROM AUTHOR]

[Objective] Leaf characteristics, photosynthetic index and key enzyme activities of carbon metabolism were studied to investigate the relationship between photosynthetic characteristics and carbon metabolism in different light environments and growth stages. [Method] Two varieties, shade tolerance Nanxiadou38 (ND38) and shade sensitive Huaxias (HX5) were used in field experiment under green shading net to investigate the specific leaf weight, leaf area per plant, photosynthetic pigment concentration, photosynthetic performance, biomass distribution, sugar levels and key enzymatic activities related to carbon metabolism. [Result] With the shade treatment during shading period, the specific leaf weight, leaf area per plant, photosynthetic pigment concentration and photosynthetic rate all decreased significantly with shading area treatment, and the decline of HX5 was more obvious than that of ND38, Biomass allocation increased in stem but decreased in leaf, and the leaf proportion of ND38 was significantly higher than that of HX5. Both soluble sugar and sucrose levels in leaves decreased significantly, but sucrose content under heavy shading was significantly lower than that under light shading, and the decline of HX5 was more obvious than that of ND38. Starch content increased significantly and the range of HX5 was higher than that of ND38. Starch content of HX5 all was higher than that of ND38. Sucrose synthetase (SS), sucrose phosphate synthetase (SPS) and sucrose invertase (Inv) decreased significantly. SS and Inv in heavy shading were significantly lower than of light shading, and there was no significant difference between varieties under the same shading treatment. During light recovery period, the difference of leaf traits among treatments decreased and the preference of leaf mass allocation ratio declined. Starch content with shading treatment was significantly higher than that of normal light. The recovery ability of ND38 was better than that of HXS. SPS and Iny of ND38 also were significantly higher than those of HXS, but SS of ND38 was higher than that of HX5 in heavy shading treatment. The recovery ability of ND38 was better than that of HXS. [Conclusion] Specific leaf weight, photosynthetic pigment concentration, photosynthetic rate and key enzyme activities of carbon metabolism decrease significantly during shading period. However, starch content and stem biomass allocation increase. During light recovery period, photosynthetic performance and enzyme activity recovered rapidly and leaf biomass allocation increase. HX5 is sensitive to shading treatment, and its photosynthetic performance and enzyme activity decrease significantly. ND38 can keep quite photosynthetic performance and equitable mass allocation during shading period. The recovery ability of photosynthetic performance and key enzymatic activities of ND38 is better than that of HX5. [ABSTRACT FROM AUTHOR]

[Objective] The study aimed to explore the effects of four weed populations on apple photosynthetic characteristics and fruit quality formation, and screen out suitable grass for planting in Zhaotong orchards. [Method] We conducted a field experiment with Fuji apples and set orchard clear-cutting as the control, and explored the effects of Artemisia absinthium(Artemisia lavandulaefolia DC), Artemisia stellate (Stellaria vestita Kurz.), Ryegrass (Lolium perenne L.) and White-flowered cheatgrass (Trifolium repens Linn) on the leaf chlorophyll content, photosynthetic characteristics and fruit quality of the fruit trees. [Result] White-flowered cheatgrass treatment could increase leaf total chlorophyll content, net photosynthetic rate (P), intercellular CO₂ concentration (C₁), stomatal conductance(G) and carboxylation efficiency (CE), while the water use efficiency (WUE) of the fruit trees was significantly reduced. The Artemisia absinthium treatment could increase leaf G, and improve C, to a certain extent, but it would reduce the total chlorophyll content and leaf CE. Artemisia stellate treatment could increase C, and the total chlorophyll content as well as leaf transpiration rate (T,) were reduced. Ryegrass treatment significantly increased WUE and CE, but significantly reduced T. Quality aspect, the various raw grass treatments increased fruit solids content by 0.88% 13.87%, reduced reducing sugar content by 2.30% 15.71%, increased total antioxidant capacity by 10.03%-40.92%, and the ryegrass treatment reduced hydrogen peroxide content by 41.80% and superoxide anion scavenging capacity by 12.92%, as compared to clear tillage. Using fuzzy membership function analysis, the comprehensive evaluation value of clear tillage, white clover, mugwort, stellaria and ryegrass were 0.4858, 0.6044, 0.5548, 0.4894 and 0.6059, respectively. [Conclusion] Different weed populations can improve the photosynthetic capacity of fruit leaves and improve fruit quality to a certain extent. Scientific evaluation of four weed populations is beneficial to screen out more reasonable grass types in orchards. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agronomica Sinica is the property of Crop Science Society of China and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Northwest A & F University - Natural Science Edition is the property of Editorial Department of Journal of Northwest A&F University (Natural Science Edition) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Kunitz trypsin inhibitor genes play important roles in stress resistance. In this study, we investigated RpKTI2 cloned from Robinia pseudoacacia and its effect on tobacco. RpKTI2 was introduced into the tobacco cultivar NC89 using Agrobacterium-mediated transformation. Six RpKTI2-overexpressing lines were obtained. Transgenic and wild-type tobacco plants were then compared for photosynthetic characteristics and endogenous hormone levels. Transgenic tobacco showed minor changes in chlorophyll content, fluorescence, and photosynthetic functions. However, the maximum photochemical efficiency (Fv/Fm) increased significantly while intercellular CO2 concentration (Ci) decreased significantly. Stomatal size and hormone content (indole-3-acetic acid, zeatin riboside, gibberellin, and indole-3-propionic acid) were reduced, while brassinosteroid content increased. Random forest regression revealed that RpKTI2 overexpression had the biggest impact on carotenoid content, initial fluorescence, Ci, stomatal area, and indole-3-acetic acid. Overall, RpKTI2 overexpression minimally affected chlorophyll synthesis and photosynthetic system characteristics but influenced stomatal development and likely enhanced the antioxidant capacity of tobacco. These findings provide a basis for future in-depth research on RpKTI2. [ABSTRACT FROM AUTHOR]

The rare and endangered wild plant, Horsfieldia hainanensis, has been listed as a second-level key protected plant in China. Currently, its habitat is severely damaged, and the population has dramatically declined, necessitating urgent intervention for protection. In this study, the aim was to explore the correlations and differences from the perspectives of photosynthetic characteristics and leaf structure, providing scientific references for in-situ conservation and ex-situ cultivation. The results revealed the following: (1) The maximum net photosynthetic rate (Pmax) and light saturation point (LSP) of mature trees were significantly higher than those of seedlings, while the light compensation point (LCP), CO2 compensation point (CCP), and CO2 saturation point (CSP) were significantly lower in seedlings. (2) The average daily net photosynthetic rate of mature trees was significantly higher than that of seedlings. When both mature trees and seedlings exhibited a “midday depression” phenomenon, accompanied by an increase in intercellular CO2 concentration (Ci), it indicated that the “midday depression” was caused by non-stomatal limiting factors. (4) Both mature trees and seedlings showed peak values of water use efficiency (WUE) under low light conditions. Mature trees had smaller upper and lower epidermis thickness but larger leaf thickness, and their leaf structure, characterized by well-developed palisade and spongy tissues, conformed to the cellular structure adaptations for low light. Therefore, both were more adapted to low light conditions. (5) The stomatal density (SD) and individual stomatal area (SA) of seedlings were significantly higher than those of mature trees. (6) The total chlorophyll content of mature trees was significantly higher than that of seedlings, while the chlorophyll a/chlorophyll b ratio was significantly lower in mature trees and remained below three in both cases. In summary, the photosynthetic capacity and light adaptability of mature trees are stronger than those of seedlings, but both mature trees and seedlings exhibit shade-tolerant characteristics. For in-situ conservation, it is possible to promote the growth and development of seedlings by appropriately employing artificial “windowing” or shading methods based on the actual growth environment of the seedlings. In the case of ex-situ cultivation, seedlings should be provided with appropriate shading initially, while ensuring sufficient moisture and CO2 concentration. As the plants grow, the shading intensity can be gradually reduced. Once the plants reach maturity, they have a broader range of light adaptability and can be transplanted to environments with less shading.

[ Objective ] This study aims to explore the protective mechanism of exogenous silicon on water metabolism and photosynthesis of Cucurbita pepo L. seedlings under salt stress , and to provide theoretical reference for salt resistance of C . pepo L.. [ Methods ] Using “ Hanlu 7042 ” C . pepo L. variety as the test material and hydroponic experiment , four treatments were set : Control , silicon treatment ( 0.3 mmol / L Na 2 SiO 3 · 9H 2 O ), salt stress ( 150 mmol / L NaCl ), salt stress+silicon treatment ( 0.3 mmol / L Na 2 SiO 3 · 9H 2 O+150 mmol / L NaCl ) . After 10 days of treatment , root morphology and activity , leaf water con- tent and water potential , photosynthetic parameters , chlorophyll content , chlorophyll fluorescence param- eters , and expression of aquaporin genes were determined. [ Results ] Salt stress inhibited the growth of C . pepo L. seedling roots , and decreased root activity , leaf water content , and leaf water potential and tran- spiration. Salt stress also affected the photosynthetic system , net photosynthetic rate , stomatal conduct- ance , chlorophyll content , and PSⅡ photochemical efficiency. Exogenous silicon improved the root mor- phology and activity of C . pepo L. seedlings under salt stress , also improved plant water status , and leaf water content , leaf water potential , and transpiration by promoting the expression of genes PIP1 ; 2 , PIP1 ; 3 , PIP1 ; 5 , PIP1 ; 7 , PIP2 ; 1 , PIP2 ; 4 , PIP2 ; 6 , and PIP2 ; 8 , PIP2 ; 9 and PIP2 ; 12 . The exogenous silicon also increased the stomatal conductance , chlorophyll content , net photosynthetic rate , PSⅡ maximum photochemical efficiency , PSⅡ actual photochemical efficiency , and photochemical quenching coefficient , decreased intercellular carbon dioxide concentration and non-photochemical quench- ing coefficient , enhanced the photosynthesis of seedlings under salt stress. [ Conclusion ] 0.3 mmol / L sili- con could improve the water metabolism and photosynthesis of C . pepo L. seedlings under salt stress , and thus enhance the ability of C . pepo L. seedlings to resist salt stress.

[Objective] The study aims to explore the effects of different foliar fertilizers on the photosyn thetic characteristics, fruit quality, and yield of greenhouse strawberries, and to screen suitable foliar fer tilizers. [Methods] The strawberry variety “Monterey” planted in the greenhouse of Moujiatai Strawberry in Xigu District of Lanzhou City, Gansu Province was used as test materials. Under sufficient fertilization, five types of foliar fertilizers, including classic 750×liquid (T1), Huapu 1 500×liquid (T2), and Runliang 750×liquid (T3), 500×Adela fruit (T4), and 1500×potassium dihydrogen phosphate (T5), were ap plied topdressing at four growth stages, with water as control. The photosynthetic parameters, fruit qual ity, biomass, and yield were measured. [Results] (1) After spraying different foliar fertilizers, the bio mass and chlorophyll content of strawberry plants were significantly increased, and the net photosynthetic rate and transpiration rate of leaves were significantly increased, while the intercellular carbon dioxide con centration was higher than that of CK. (2) For fruit quality, T2 and T3 treatments significantly improved the strawberry fruit shape index, while T1 and T5 treatments significantly increased fruit volume and weight. Among them, the average single fruit mass of T1 was increased by 35.04% compared with CK, while the transverse and longitudinal diameters of T5 fruits were increased by 49.39% and 40.64%, re spectively. (3) The quality of strawberry fruits was effectively improved by various foliar fertilizer treat ments, and T1 treatment was the best. The content of vitamin C, soluble solids, soluble proteins, reduc ing sugars, and soluble sugars were increased by 30.84%, 33.5%, 38.5%, 27.9%, and 36.2%, respec tively, compared with CK. The content of titratable acid was the lowest, and the sugar acid ratio was the highest, with significant difference compared with CK. (4) Spraying appropriate fertilizer significantly in creased plant biomass, max single fruit weight, and fruit yield; treatment T1 had the highest yield, an in crease of 13.65% compared with CK. [Conclusion] The application of appropriate foliar fertilizer effective ly improves the nutritional growth status of strawberries, enhances the quality of strawberry fruits, and significantly increases yield. The comprehensive effect is best when applying classic 750×liquid.

Abstract Background Several plants are facing drought stress due to climate change in recent years. In this study, we aimed to explore the effect of varying watering frequency on the growth and photosynthetic characteristics of Hosta ‘Guacamole’. Moreover, we investigated the effect of high-nitrogen and -potassium fertilizers on alleviating the impacts of drought stress on the morphology, photosynthetic characteristics, chlorophyll fluorescence, fast chlorophyll a fluorescence transient, JIP-test parameters, and enzymatic and non-enzymatic scavenging system for reactive oxygen species (ROS) in this species. Results Leaf senescence, decreased chlorophyll contents, limited leaf area, and reduced photosynthetic characteristics and oxygen-evolving complex (OEC) activity were observed in Hosta ‘Guacamole’ under drought stress. However, high-nitrogen fertilizer (30-10-10) could efficiently alleviate and prevent the adverse effects of drought stress. High-nitrogen fertilizer significantly increased chlorophyll contents, which was higher by 106% than drought stress. Additionally, high-nitrogen fertilizer significantly improved net photosynthetic rate and water use efficiency, which were higher by 467% and 2900% than those under drought stress. It attributes that high-nitrogen fertilizer could reduce transpiration rate of leaf cells and stomatal opening size in drought stress. On the other hand, high-nitrogen fertilizer enhanced actual photochemical efficiency of PS II and photochemical quenching coefficient, and actual photochemical efficiency of PS II significantly higher by 177% than that under drought stress. Furthermore, high-nitrogen fertilizer significantly activated OEC and ascorbate peroxidase activities, and enhanced the performance of photosystem II and photosynthetic capacity compared with high-potassium fertilizers (15-10-30). Conclusions High-nitrogen fertilizer (30-10-10) could efficiently alleviate the adverse effects of drought stress in Hosta ‘Guacamole’ via enhancing OEC activity and photosynthetic performance and stimulating enzymatic ROS scavenging system.

The photosynthetic fluorescence characteristics of 8 Zanthoxylum bungeanum varieties in the Loess Plateau region of central Gansu were explored to provide reference for the excellent cultivar screening and adaptability research of Zanthoxylum bungeanum in the Loess Plateau region of central Gansu. By taking the 2-year-old seedlings of 8 Zanthoxylum bungeanum varieties as the research object, the photosynthetic parameters such as the net photosynthetic rate and stomatal conductivity of Zanthoxylum bungeanum were measured by using the photosynthetic analyzer, and the chlorophyll fluorescence characteristics such as the initial fluorescence and photochemical quenching coefficient were measured by using the luminoscope. Then, the photosynthetic characteristics and chlorophyll fluorescence parameters of leaves among different Zanthoxylum bungeanum varieties were compared and analyzed. The results showed that: the photosynthetic characteristics were presented as the net photosynthetic rate ( Pn ) and transpiration rate ( Tr ) of different Zanthoxylum bungeanum varieties decreased gradually with time. The Gs of Qin’an Dahongpao and Wucimei Zanthoxylum bungeanum decreased gradually with time. Nanqiang No.1, Goujiao and Shizitou showed a trend of increasing first and then decreasing, while other varieties had no obvious variation tendency. The Pn, stomatal conductivity ( Gs ) and transpiration rate ( Tr ) of Wucimei Zanthoxylum bungeanum were the highest in July. Except that the intercellular CO2 concentration ( Ci ) of Huanggai and Goujiao decreased first and then increased, the intercellular CO2 concentration ( Ci ) of other Zanthoxylum bungeanum varieties showed a gradual rising tendency. The fluorescence characteristics showed that except for the F0 of Qin’an Dahongpao and Goujiao increased first and then decreased with time, the initial fluorescence (F0) of other varieties decreased gradually with time. The maximum fluorescence (Fm) of Qin’an Dahongpao and Qin’an No.1 in different periods was significantly higher than that of other varieties. The maximum primary photochemical quantum efficiency (Fv/Fm) of PSⅡ in each Zanthoxylum bungeanum variety did not change significantly during the whole growth period, which was basically maintained at 0.6-0.8. In September, the photochemical pathway transformation energy (ψPSⅡ) and electron transporting rate (ETR) of Wucimei Zanthoxylum bungeanum were significantly higher than those of other varieties. The photochemical quenching coefficient (qP) of each Zanthoxylum bungeanum variety showed different trends with time, but there was no significant change in the whole growth period of Qin’an Dahongpao. [ABSTRACT FROM AUTHOR]

Peanut production is threatened by climate change. Damage to seedlings from low temperatures in early spring can limit yield. Plant adaptations to chilling stress remain unclear in peanut seedlings. It is essential to understand how peanut acquires chilling tolerance.We evaluated effects of chilling stress on growth and recovery of peanut seedlings. We compared and analysed biological characteristics, antioxidants, photosynthesis, biochemical and physiological responses, and nutrient absorption at varying levels of chilling.Compared with chilling‐sensitive FH18, the reduced impact of chilling stress on chilling‐tolerant NH5 was associated with reduced ROS accumulation, higher ascorbate peroxidase activity and soluble sugar content, lower soluble protein content, and smaller reductions in nutrient content during stress. After removal of chilling stress, FH18 had significant accumulation of O2•− and H2O2, which decreased photosynthesis, nutrient absorption, and transport. ROS‐scavenging reduced damage from chilling stress, allowed remobilization of nutrients, improved chilling tolerance, and restored plant functioning after chilling stress removal.These findings provide a reference for targeted research on peanut seedling tolerance to chilling and lay the foundation for bioinformatics‐based research on peanut chilling tolerance mechanisms. [ABSTRACT FROM AUTHOR]

Simple Summary: Seaweed aquaculture plays an important role in global food supply, but single-species intensive seaweed aquaculture has problems related to simple industrial structure and risk susceptibility. Therefore, there is an urgent need to establish a series of large-scale seaweed rotational culture models to address the current industrial challenges in algae culture. The culture of macroalgae is mainly affected by environmental factors such as water temperature and light. In this study, we constructed a rotational culture model by carrying out experiments with three species of macroalgae, observing in situ their photosynthetic activity responses to different temperature and light conditions. The results of this study can provide a theoretical basis for the establishment of large-scale rotational aquaculture, which can effectively improve the ecological and economic value of macroalgae aquaculture. Seaweed farming has made outstanding contributions to food supply and the restoration of the ecological environment despite the limitations in production and ecological effects due to the current intensive farming of single algae species. These limitations can be overcome by selecting suitable algal species based on their physiological characteristics and by constructing a large-scale seaweed rotation model. This study carried out a trial culture in aquaculture sea areas, and performed in situ monitoring of the environmental conditions and physiological characteristics of Saccharina japonica, Hizikia fusiformis, and Gracilariopsis lemaneiformis. Additionally, a comparative analysis of the three macroalgae at different times was conducted to determine their response characteristics to environmental factors. The results showed that: (1) The three macroalgae had varying light tolerance. The effective quantum yield of Hizikia fusiformis and Gracilariopsis lemaneiformis remained unchanged during the changes in light environment, while that of Saccharina japonica first decreased and then recovered. (2) The relative electron transport rates of the three macroalgae were significantly different under different temperature conditions. Hizikia fusiformis and Saccharina japonica exhibited the highest relative electron transport rates (70.45 and 106.75, respectively) in May (20.3 °C). Notably, Gracilariopsis lemaneiformis demonstrated good growth and exhibited the highest relative electron transport rate (93.07) in September (27.5 °C). These findings collectively support the feasibility of establishing a macroalgae rotation model. Based on the combined environmental conditions of the seas in Shandong, Zhejiang, and Fujian, a macroalgae rotation model was proposed. The application of this model in the construction of artificial seaweed farms in marine ranches can provide a stable output of large-scale seaweed production and ecological benefits. [ABSTRACT FROM AUTHOR]

This study was designed to determine the optimal nitrogen application rate for strong-gluten wheat cultivation in the North China Plain. Employing Zhongmai 578, a strong-gluten wheat variety, a field experiment was conducted with the following four nitrogen levels: 0 kg/ha (N0), 150 kg/ha (N1), 210 kg/ha (N2), and 270 kg/ha (N3). The research focused on examining the impact of nitrogen application on the photosynthesis, yield, and quality of strong-gluten wheat. The findings revealed that the N2 treatment (210 kg/ha) yielded the highest results compared to the N0 treatment. Photosynthetic parameters, including chlorophyll content in wheat flag leaves, generally exhibited an increase followed by a decrease, peaking at 7 days after anthesis (except for the transpiration rate, which peaked at 14 days post-anthesis). In the first year, quality indices such as water absorption, capacity, sedimentation value, ductility, protein, and wet gluten initially increased and then decreased with rising nitrogen levels. Conversely, in the second year, these quality indices, including hardness, showed a progressive increase with elevated nitrogen application. These results indicate that enhanced nitrogen application can significantly improve the photosynthetic characteristics of strong-gluten wheat, thereby augmenting both yield and quality. Within the parameters of this experiment, an application of 210 kg/ha of nitrogen emerged as the optimal rate, promoting the superior yield and quality of strong-gluten wheat in the North China Plain. [ABSTRACT FROM AUTHOR]

Abundant light and heat in the Hexi Oasis Irrigation Area in China provide superior natural conditions for agricultural development. To study the maize–soybean planting system of intercropping and determine superior group yield and economic benefits in the Hexi Oasis Irrigation Area, eight treatments were set up in 2022–2023: maize–soybean intercropping with a bandwidth of 1.8 m and a row ratio of 2:3 (M1S3), a bandwidth of 1.8 m and a row ratio of 2:4 (M1S4), a bandwidth of 2.0 m and a row ratio of 2:3 (M2S3), a bandwidth of 2.0 m and a row ratio of 2:4 (M2S4), a bandwidth of 2.2 m and a row ratio of 2:3 (M3S3), a bandwidth of 2.2 m and a row ratio of 2:4 (M3S4), monocropping maize (M), and monocropping soybean (S). We analyzed the effects of changes in bandwidth–row ratios on photosynthetic characteristics, yield, and interspecific relationships in these treatments during two crop reproductive periods. Our results showed the following: (1) Under the intercropping system, the photosynthetic capacity of maize was highest when the row ratio was 2∶3 and bandwidth was 1.8 m. The net photosynthetic rate (Pn) increased by 1.72% to 48.90%, the transpiration rate (Tr) increased by 5.53% to 118.10%, and stomatal conductance (Gs) increased by 2.82% to 86.49% compared with other planting systems. Increasing the bandwidth from 1.8 m to 2.2 m improved the photosynthetic characteristics of soybean, increasing Pn, Tr, and Gs by 3.44% to 74.21%, 3.92% to 53.69%, and 2.41% to 55.22%, respectively. (2) The yield of maize and soybean under monocropping was significantly higher than that under intercropping. In the intercropping treatments, the average yield of crops in the M3S3 system was 16,519.4 kg ha−1, an increase of 6.48% compared with the M3S4 system, indicating that the reduction of one row of soybean in the same bandwidth system increases crop yield; The average economic benefit of the M3S3 system over two years was 35,171.73 CNY ha−1, which increased by 13.3 and 80% compared with the average economic benefit of maize and soybean monocropping, indicating that the intercropping system leads to better economic results for farmers than monocropping. (3) In the two-year experiment, the land equivalent ratio (LER) was highest in the M3S3 model, averaging 1.25 over the two years, showing better land productivity compared with other intercropping systems. (4) When bandwidth was 1.8, 2.0, or 2.2 m, the LER decreased by 8.3, 5.9, and 5.6% when planting an additional row of soybeans, the relative crowding coefficient of soybeans in the respective bandwidths increased by 4.59, 4.72, and 0.75%, the competition ratio of maize (CRM) increased by 22.94, 16.97, and 12.74%, the competition ratio of soybean (CRS) decreased by 20.47, 17.61, and 16.78%, and the competitive power of maize was greater than that of soybean, indicating that the increase in soybean rows in the same bandwidth system would weaken the competitive advantage of soybean, resulting in crop yield and economic benefit reduction. When the row ratio was 2:3 or 2:4, bandwidth increased from 1.8 m to 2.2 m, LER decreased by 3.31 and 0.86%, intercropping maize aggressiveness (AM) decreased by 7.55 and 12.50%, CRM decreased by 18.04 and 24.84%, and CRS increased by 17.32 and 22.77%, respectively, which indicated that the increase in bandwidth under different row ratio systems could improve the competitive advantage of intercropping soybean, thereby improving crop yield and economic benefits. (5) The AHP method, entropy weight method, and TOPSIS analysis showed that M3S3 ranked first, with the highest comprehensive evaluation (0.6017). In conclusion, the M3S3 planting system can better coordinate crop interspecies relationships, with higher land yield and economic benefit, and can be used as a suitable maize–soybean intercropping system in the Hexi oasis irrigation area. [ABSTRACT FROM AUTHOR]

[Objective] The paper aimed to study the effects of combined application of biochar and nitrogen fertilizer on SPAD value, photo- synthetic characteristics, dry matter accumulation, transport, grain filling rate and yield of spring wheat in irrigation area of northern Xinjiang, which provided a basis for rational application of different amounts of nitrogen fertilizer and combined application of biochar in irrigation area of northern Xinjiang and increasing yield and efficiency of farmland. (Method) In the study, the high-quality spring wheat variety Xinchun 37' in Xinjiang was used as the test material, and a randomized block design was used, four nitrogen fertilizer levels were set up as non-nitro- gen fertilizer (NO:0 kg/hm²), conventional nitrogen fertilizer (N1: 300 kg/hm²), nitrogen fertilizer reduction 15% (N²: ²55 kg/hm²), nitrogen fertilizer reduction 30% (N3: ²10 kg/hm²); Two biochar levels were set up as non-biochar (BO:0 kg/hm²) and biochar (B1: ²0 x 10³ kg/hm²), including 8 treatments as BONO, BINO, BONI, BINI, BON², BIN², BON3, BI N3; The SPAD value of flag leaf, photosynthetic indexes (net photosynthetic rate, stomatal conductance, transpiration rate, intercellular CO, concentration), dry matter accumulation and transport during growth period, grain filling rate, yield and its composition of spring wheat were measured, to clarifying the effects of different a-mounts of nitrogen fertilizer and biochar on the growth of spring wheat. (Result) Compared with non-biochar and non-nitrogen fertilizer (BONO),15% reduction of nitrogen fertilizer combined with biochar (B1N²) could significantly increased the SPAD value of flag leaf, net photosynthetic rate, stomatal conductance, transpiration rate, dry matter accumulation and transport rate, grain filling rate and yield of spring wheat. Under the BIN² treatment, the SPAD value increased by 13.17%-91.70%, the net photosynthetic rate increased by 17.4²% 87.30%, the stomatal conductance increased by 16.00%-²9.41%, and the transpiration rate increased by ²5.35% -79.81%. At the maturity stage of spring wheat, the dry matter of grains increased by ²8.87%, and the yield increased by 30.²3%. [Conclusion] Appropriate amount of biochar ²0 x 10³ kg/hm² and nitrogen fertilizer ²55 kg/hm² (B1 N²) can initially achieve the purpose of increasing spring wheat yield and reducing nitrogen fertilizer application, and provide a theoretical basis for the formulation of scientific application strategies of nitro- gen fertilizer and biochar in farmland in northern Xinjiang irrigation area. [ABSTRACT FROM AUTHOR]