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Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology 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.)

Extracting the leaves has been one of the most fundamental researches for the phenotypic traits of plants. However, it is difficult to further improve the accuracy of leaves segmentation, due to the mutual occlusion between leaves in rosette plants. It is still lacking in the leaf edge characteristics, particularly for the small target of young leaves. In this study, an improved instance segmentation benchmark Mask R-CNN model was proposed to realize an accurate segmentation for the plant leaves. The Cascade R-CNN was also introduced to generate the selection of the proposal boxes for the region proposal network. The boxes were first sent into the Head1 convolutional network with a threshold of 0.5, and then the detection was input into the Head 2 convolutional network with a threshold of 0.6, and finally, the detection was fed into the Head 3 convolutional network with a threshold of 0.7. Three cascaded networks were used to gradually increase the threshold, where the output of the previous network was applied to the higher threshold of the next network, indicating the high quality of the detection branch. After the segmentation branch full convolutional layer (FCN), an attention mechanism (SeNet) and a two-layer 3×3 convolution module were added to weigh the features of the segmentation branch, and further to extract the leaf edge segmentation. The segmentation of multi-scale leaves was also adopted for the leaves of different sizes in an image in the test process. The original and enlarged images were input into the model at the same time for the leaves segmentation. The optimal target on multiple scales was achieved using Non-Maximum Suppression (NMS). The ResNeXt101 was selected as the backbone network to extract the characteristics of leaves. An improved model of deep learning was also utilized at the same time. The image enhancement included random mirroring, rotation, enlargement, and size adjustment. There was no longer requiring for the special function library support, indicating the simplified data enhancement. The improved model had effectively reduced the blade occlusion, edge blur, and small target in the blade segmentation. Correspondingly, the Symmetric Best Dice (SBD) was 90.3% in the CVPPP Leaf Segmentation Challenge (LSC), which was 2.3 percentage points higher than that in Mask R-CNN, particularly than 1 percentage points than before. The improved neural network model was suitable for the leaf segmentation. The finding can provide a more accurate leaf segmentation for the plant phenotype using image processing, indicating a high application value in the research field of plant leaves. [ABSTRACT FROM AUTHOR]

Objective: To observe the effect of auricular pressure beans (APN) combined with Compound Tung-Leaf Burn Oil (CTBO) on perioperative anxiety and pain in patients undergoing circumcision., Methods: This study included 100 patients undergoing circumcision with the disposable circumcision anastomosis stapler in our hospital from August 2023 to November 2023, of whom 50 received routine circumcision nursing care (the control group) and other 50 APN combined with compound CTBO in addition (the observation group). We compared between the two groups the anxiety scores before any intervention, 30 minutes before and 24 hours and 10 days after operation, the pain scores 24 hours postoperatively and at the first change of wound dressing, the frequency of 3-day postoperative sleep awakenings, the incidence of complications, and the satisfaction of the patients., Results: Totally, 94 patients completed the study, 46 in the observation and 48 in the control group. The anxiety scores exhibited no statistically significant difference between the two groups of patients before any intervention (P > 0.05), but were markedly lower in the observation than in the control group at 30 minutes before and 24 hours and 10 days after surgery (P<0.05), and so were the pain scores 24 hours after surgery and at the first change of wound dressing (P<0.05), and the frequency of 3-day postoperative sleep awakenings (P<0.05). The satisfaction rate of the patients was remarkably higher (P<0.05) while the incidence of complications significantly lower in the observation group than in the control (P<0.05)., Conclusion: Auricular pressure beans combined with Compound Tung-Leaf Burn Oil can effectively alleviate perioperative anxiety, reduce postoperative pain and improve satisfaction of the patients undergoing circumcision.

Fluorescence has unique luminescence characteristics. The combination of excitation light and emission light can greatly reduce the interference of background signals and greatly improve the sensitivity of the detection system. Many scholars at home and abroad obtain the optimal excitation and emission wavelengths of the analyte based on the principle of photoluminescence of fluorescent substances, and have developed miniaturized, low-cost dedicated instruments. However, the current portable instruments which focus on detecting pesticide residues in the solution system cannot realize directly detection pesticide residues on the surface of vegetable leaves. In this study, a feasible model for pesticide residues and fluorescence intensity on the leaf surface was proposed, and a portable detection instrument for pesticide residues on the leaf surface was designed by optimizing the light path structure to suppress the interference of stray light on the leaf surface. Firstly, the best excitation wavelength and best emission wavelength of acetamiprid pesticide in standard solution and three plant leaves were determined as 350 and 500 nm, respectively. An LED with a central wavelength of 350 nm and a maximum drive current of 100 mA was selected as the excitation light source, and a photodiode with a peak response range from 480 to 580 nm was used as the photoelectric detection device. A filter with a center wavelength of 500 nm was used to only let through the emission wavelength of the acetamiprid pesticide pass to reduce the interference of the secondary spectrum. Then the optimal parameters of the optical path are determined. The fluorescence experiments results showed that the fluorescence intensity excited by acetamiprid pesticide on the leaf surface was the highest when the light Angle was 45°. By calculating the optical path size, it was found that the illumination of the blade was the largest when the direct distance from the LED laser source to the blade was 4.89 cm and the vertical distance was 3.46 cm. In addition, in view of the diffuse reflection problem of the light source illuminating the surface of the blade, a diffuse reflection device was designed to achieve the maximum absorption of light energy. The control circuit, driving circuit and detection circuit were designed according to the requirement of weak fluorescence signal detection. A signal detection system was designed with STM32 chip as the main control chip to collect the voltage signal of the detection circuit, and the pesticide residue value was calculated according to the working curve of pesticide residue value. The PWM wave was output to modulate the LED light source and the difference between the frequency of detecting light and the frequency of ambient light can suppress the interference of ambient light to the light source. Then, SPI and I2C communication protocols were used to communicate with AD acquisition chip and OLED display screen to realize real-time detection of pesticide residues and real-time display of pesticide residues. Finally, the measuring value relation model of the portable measuring instrument was established. The determination coefficient of the model reached 0.875, and the root mean square error is 0.405 mg/L. The portable fluorescence spectrometer designed in this study can quickly, accurately and non-destructively detect pesticide residues on the surface of leaves, which provided a reference for the development of a more universal portable detection instrument. [ABSTRACT FROM AUTHOR]

Biomass carbon materials have the advantages of low cost, wide source, adjustable and controllable porosity, diverse morphology, easy production, and easy to incorporate heteroatoms. Therefore, the development and application of biomass carbon-based materials have become a very important area in modern materials science. In this work, the plant leaves were treated by hydrothermal oxidation with different oxidants. Then the obtained product was pyrolyzed at 600 ℃ to obtain biomass carbon materials. Compared with the traditional pyrolysis methods, hydrothermal oxygen reaction could reduce the pyrolysis temperature and maintain the vein structure of leaves to a great extent. Graphene like thin-layer carbonization materials were obtained. The samples were characterized by XRD, XPS, TEM and SEM. The results show that the properties of the carbon materials obtained by hydrothermal oxidation with different oxidants were different. When the oxidant was KMnO4, the obtained biomass carbon material (MnOC) retained the original microscopic pores of the blade and formed new pores. Its specific surface area could reach 482.934 m2/g with an average pore size of 3.833 nm. XRD and XPS results show that the degree of graphitization of MnOC was relatively high and preserved the N element (6.5%) as much as possible. TEM and AFM analysis shows that MnOC had a lamellar structure with the thickness of less than 2 nm. The MnOC exhibited the capacitance of 191.15 F/g at 1 A/g. [ABSTRACT FROM AUTHOR]

Grading seeds based on grain size is an effective measure to improve population regularity degree and increase the yield of summer maize. Taking Denghai 605 as the experimental material, we set up a field experiment with treatments based on grain size: large seeds (L), medium-round seeds (MR), medium-flat seeds (MF), medium-round and medium-flat mixed seeds (MRF), and small seeds (S), with no-grading seeds as control (CK). We investigated seedling emergence rate, population regularity degree (including height, ear height and stem diameter), seedling sturdiness index, photosynthetic characteristics, dry matter accumulation and distribution characteristics, and yield. The results showed that the emergence rate followed an order of L>MR>MRF>MF>CK>S, with that of L treatment differed little from MR, MF and MRF treatments, but being significantly higher than S and CK treatments. Plant height and stem diameter population regularity degree of MRF treatment before seven-leaf stage was not different from those of L, MR, MF and S treatments, but significantly higher than those of CK. At the tasseling stage, all treatments had higher population regularity degree of plant height than other stages. Ear height population regularity degree of L, MR, MF, MRF, and S increased by 11.1%, 10.3%, 9.5%, 7.1%, and 6.4% compared with CK, respectively. The seedling sturdiness index of MRF treatment increased by 36.7% compared with S treatment, but was not significantly different from L treatment. The leaf area index of the L and MRF treatments was significantly higher than that of CK, and both had higher population photosynthetic properties. The population dry matter accumulation showed a pattern as L>MR>MRF>MF>CK>S. There was no significant difference among L, MR, and MRF treatments, but that in L being obviously higher than MF, CK, and S treatments. After seed grading, the number of harvested ears of the L and MRF treatments increased significantly, and the yield were shown as L>MR>MRF>MF>CK>S. There was no difference between the yield of MRF, MR and MF treatments. In conclusion, the performance of L treatment was improved but the number was small. Considering the grading cost and yield, the MRF treatment can save the seed amounts of sowing, realize mechanized sowing and precision sowing.

Analyzing the pattern of altitudinal variation in the leaf traits and their networks of a particular tree species of similar age and its influencing factors could contribute to understanding the impacts of environmental factors on leaf traits and excluding the interference of genetic factors. We investigated the stomatal, structural, chemical, and vein traits of Daphniphyllum macropodum leaves in middle-aged forests, following the altitudinal gradient (1100, 1500, and 1900 m) on Mao'er Mountain. The objectives of this study were to reveal patterns in leaf trait and leaf trait networks variation, the life strategy of the tree species, and the major environmental factors affecting the altitudinal variations. The results showed that leaf area, specific leaf area, leaf thickness, leaf dry matter content, chlorophyll content, nitrogen content, phosphorus content, C:N, C:P, vein density, and vein diameter varied significantly across altitudes. Mean annual temperature and total radiation explained 42.1% and 16.2% of leaf-trait variation, respectively. They served as key environmental factors driving the altitudinal variation in leaf traits. Mean annual temperature exhibited the greatest influence on leaf area ( R 2 =0.73), and total radiation exerted the most prominent effect on leaf thickness ( R 2 =0.72). Both relationships were significantly positive. D. macropodum exhibited low leaf nitrogen and phosphorus at the low altitude of 1100 m, and the overall and local trait networks were loose, adopting a conservative resource strategy. At the medium altitude of 1500 m, leaf nutrient contents were relatively high. The overall network of leaf traits was tightly connected and local network was loose. By enhancing the dependency among leaf traits, and improving phosphorus utilization efficiency, D. macropodum could cope with competition in deciduous forests and adopt resource acquisition strategies. Further, at the highest altitude of 1900 m, D. macropodum had relatively large leaf thickness, chlorophyll content, and leaf dry matter content, but relatively small leaf area. The local network connections were tight while the overall network looseness, indicating a resource conserving strategy. The trade-off relationship between C:P and leaf phosphorus content was closely related to phosphorus use efficiency, and its variation was an important indicator for identifying life strategies of D. macropodum in different altitudes.

Artemisiae Argyi Folium is commonly used in clinical practice. Artemisiae Verlotori Folium, the dried leaves of Artemisia verlotorum, is often used as a folk substitute for Artemisiae Argyi Folium in Lingnan area. In this study, gas chromatography-triple quadrupole mass spectrometry(GC-MS) was used to detect the volatile oil components of 27 samples of Artemisiae Verlotori Folium and 13 samples of Artemisiae Argyi Folium, and the volatile components were compared between the two species. The internal standard method was combined with multi-reaction monitoring mode(MRM) to determine the content of six major volatile components. Hierarchical clustering analysis(HCA) and orthogonal partial least squares-discriminant analysis(OPLS-DA) were carried out for the content data. The results showed that the Artemisiae Argyi Folium samples had higher content and more abundant volatile oils than the Artemisiae Verlotori Folium samples. Artemisiae Argyi Folium mainly had the components with lower boiling points, while Artemisiae Verlotori Folium mainly had the components with higher boiling points. Terpenoids were the main volatile components in Artemisiae Verlotori Folium(mainly sesquiterpenoids) and Artemisiae Argyi Folium(monoterpenoids). In addition, Artemisiae Argyi Folium had higher content of oxygen-containing derivatives than Artemisiae Verlotori Folium. Furthermore, the stoichiometric analysis showed that the two species could be distinguished by both HCA and OPLS-DA, indicating that the volatile components of the two were significantly different. This study can provide a scientific basis for the quality evaluation and data support for the local rational application of Artemisiae Verlotori Folium in Lingnan.

In order to ensure the image acquisition quality of plant leaves and improve the image segmentation accuracy of plant phenotypes, a segmentation method based on deep learning was established. Based on the Caffe deep learning framework, a full convolutional neural network(FCN) was constructed. The supervised learning method was adopted to realize the segmentation of the leaf image by labeling datasets and creating dataset labels. This method fully utilized the feature that the FCN did not limit the size of the input image and achieved end-to-end image segmentation. At the same time, the data augmentation method was used to solve the problem that the training time was long and the convergence was not easy under the condition that the blade data set was scarce. The experimental results showed that the deep learning effect was remarkable in the division of plant leaves, pixel accuracy reached 91%, Mean IU reached 78.52%, technical indicators was better than most of the traditional image segmentation algorithm. [ABSTRACT FROM AUTHOR]

Stem photosynthesis widely presents in desert plants, which increases carbon uptake capacity. In this study, we measured the photosynthetic characteristics of leaves and stems in seven desert woody plants ( Populus euphratica , Populus alba var. pyramidalis , Populus pruinose , Haloxylon ammodendron , Calligonum rubicundum , Calligonum caput-medusae , Ammopiptanthus mongolicus ) in the same habitat, using a portable Li-6400XT photosynthesis system combined with P-Chamber. We analyzed stem photosynthetic rate and its relationship with leaf photosynthetic rate. We measured the stem functional traits, including water content, stem dry matter content, chlorophyll content, water potential, non-structure carbohydrate (NSC), etc ., to find out the main affecting factors of stem photosynthesis. The results showed that stem photosynthetic rate of seven species ranged from 0.72 to 1.71 μmol·m -2 ·s -1 , with the largest of P. pruinose and the smallest of H. ammodendron . Stem photosynthetic rate could offset CO 2 of stem respiration by 57%-83%. Leaf photosynthetic rate of the seven sepceis ranged from 12.80 to 22.54 μmol·m -2 ·s -1 , with H. ammodendron and A. mongolicus being lower than those of the other five species. There was a significant positive correlation between leaf photosynthetic rate and stem photosynthetic rate. Stem water use efficiency was 2.2-7.7 times of the leaf. Chlorophyll content, NSC, stem respiration rate, and leaf photosynthetic rate were the main factors affecting stem photosynthesis.

The quality of moxa is a key factor affecting the efficacy of moxibustion. Traditional moxa grades are evaluated by the leaf-to-moxa ratio, but there is a lack of support from scientific data. Scanning electron microscopy(SEM), Image Pro Plus, Van Soest method, and stimultaneous thermal analysis(TGA/DSC) were used to characterize the scientific implication of the combustion differences between moxa with different leaf-to-moxa ratios(processed by crusher). The results showed that the median lengths from non-secretory trichomes(NSTs) of natural NSTs and moxa with leaf-to-moxa ratios of 3∶1, 5∶1, 10∶1, and 15∶1 were 542.46, 303.24, 291.18, 220.69, and 170.61 μm, respectively. The cellulose content of moxa increased significantly(P&lt;0.05) with the increase in leaf-to-moxa ratio and the combustion parameters(T&#95;i, t&#95;i, D&#95;i, C,-R&#95;p,-R&#95;v, S, D&#95;b, and J&#95;(total)) all showed an increasing trend. The correlation results showed that the burning properties of moxa(T&#95;i,-R&#95;v, t&#95;i, and J&#95;2) were significantly and positively correlated with cellulose content. NSTs with a length of 1-200 μm were significantly and positively correlated with J&#95;2. NSTs with a length of 200-600 μm were significantly and positively correlated with J&#95;1, T&#95;(peak2), T&#95;(peak1), and-R&#95;v, and negatively correlated with J&#95;(total), T&#95;b, and t&#95;b. As the leaf-to-moxa ratio increases, the NSTs in the moxa become shorter and the cellulose content increases, which is more conducive to ignition performance, heat release, and a milder, longer-lasting burn. The &quot;NSTs-cellulose-TGA/DSC&quot; quantitative evaluation method scientifically reveals the scientific connotation of the combustion of moxa with different leaf-to-moxa ratios and provides a scientific basis for the establishment of quality evaluation methods for moxa with different leaf-to-moxa ratios.

More scholars in recent years have interest in studying the interaction between spray droplets and leaves. However, due to limitations on the computational efficiency of the computer, the physical-based approaches to simulate the processes cannot meet the requirements on both rendering efficiency and considering physical laws at the same time. Aiming at the limitation of traditional simulation on interactions between droplets and leaves, which can only be applied to horizontal leaves, an experiment-based simulation method on interactions between droplets and any leaves, together with a new algorithm on bounce direction of droplets was proposed in this study in order to improve the situation of overly cost calculation time yet poor on accuracy on fluid mechanics of the popular spray models used currently. The interaction between droplets and leaves was simulated based on the experimental results in this paper by combining the improved algorithms based on the predecessors of existing formulas. As the first step, the macro-high-speed camera was used to monitor droplet on the leaf at different angles among 0°~50° of inclination, and measure its static contact angle size. Then the pattern of changes on the static contact angle of the droplet was fitted when the leaf inclination angle was increasing, and generalizing the existing bounce judgment formula to any inclined leaf. Finally, the Monte Carlo method was introduced to calculate the direction of droplet bounce. Instead of using the original specular reflection, the direction of droplet bounce was not in accordance with a single track to run, but turbulent as a sector, making it more consistent with the real environment. The simulation in this study was carried out on the platform of Windows8 Operating System, and using OpenGL to simulate the interaction between droplets and leaves. Simulation results showed that this method can reflect the physical law of collision, bounce judgment, dwell and splash of droplet with any inclined leaf. Besides, simulation in this study prevented the abuse of computational work load caused by the fluid mechanics formulas, and furthermore, the Monte Carlo perturbation was used instead of specular reflection ,making the simulation process in the calculation relatively small while at the same time being more in line with the actual physical laws. This study provides a new way to look into the interaction between droplets and leaves, supporting the calculation on the deposition amount of plant canopy interacting with a large number of droplets, and also possibilities for real-time rendering of large-scale plant scene and fog field interaction. [ABSTRACT FROM AUTHOR]

The quality of moxa is an important factor affecting moxibustion therapy, and traditionally, 3-year moxa is considered optimal, although scientific data are lacking. This study focused on 1-year and 3-year moxa from Artemisia stolonifera and A. argyi(leaf-to-moxa ratio of 10∶1) as research objects. Scanning electron microscopy(SEM), Van Soest method, and simultaneous thermal analysis were used to investigate the differences in the combustion heat quality of 1-year and 3-year moxa and their influencing factors. The results showed that the combustion of A. stolonifera moxa exhibited a balanced heat release pattern. The 3-year moxa released a concentrated heat of 9 998.84 mJ·mg~(-1)(accounting for 54% of the total heat release) in the temperature range of 140-302 ℃, with a heat production efficiency of 122 mW·mg~(-1). It further released 7 512.51 mJ·mg~(-1)(accounting for 41% of the total heat release) in the temperature range of 302-519 ℃. The combustion of A. argyi moxa showed a rapid heat release pattern. The 3-year moxa released a heat of 16 695.28 mJ·mg~(-1)(accounting for 70% of the total heat release) in the temperature range of 140-311 ℃, with an instantaneous power output of 218 mW·mg~(-1). It further released 5 996.95 mJ·mg~(-1)(accounting for 25% of the total heat release) in the temperature range of 311-483 ℃. Combustion parameters such as-R&#95;p,-R&#95;v, D&#95;i, C, and D&#95;b indicated that the combustion heat quality of 3-year moxa was superior to that of 1-year moxa. It exhibited greater combustion heat, heat production efficiency, flammability, mild and sustained burning, and higher instantaneous combustion efficiency. This study utilized scientific data to demonstrate that A. stolonifera could be used as excellent moxa, and the quality of 3-year moxa surpassed that of 1-year moxa. The research results provide a scientific basis for the in-depth development of A. stolonifera moxa and the improvement of moxa quality standards.

This paper aims to compare the difference of growth and quality between wild and cultivated Artemisia stolonifera, thereby providing references for further development and utilization of A. stolonifera. The wild and cultivated A. stolonifera from different altitudes were collected, and the agronomic characters, moxa yield, volatile components, flavonoids, and phenolic acids were determined. The results showed that the cultivated species were taller and stronger, with more leaves and branches, than the wild species. The moxa yield and combustion quality of wild products were higher than those of cultivated products. The content of main volatile components in cultivated products was higher than that in wild products. The content of flavonoids and phenolic acids in wild products was higher than that in cultivated products. At high altitude, the ignition performance, combustion persistence, comprehensive combustion performance, and heat release during combustion of the wild and cultivated A. stolonifera. were optimal. At middle altitude, the content of main characteristic volatile components and flavone phenolic acids in the leaves of the cultivated and wild A. stolonifera were the highest. At low altitude, the combustion quality and the content of the above components of the cultivated A. stolonifera decrease significantly. Considering the combustion quality and the content of the internal components of the leaf lint, the middle and high altitude areas are suitable for the artificial cultivation of A. stolonifera.

The purpose of this study was to analyze the effects of shading intensity on the growth, yield, and quality of Artemisia stolonifera so as to provide references for the artificial cultivation of A. stolonifera. The seedlings of A. stolonifera with consistent growth underwent shading treatment at four shading intensity levels(0, 55%, 85%, and 95%) with different layers of black shading nets. The agronomic indexes, yield, moxa yield, total ash, quality characteristics of moxa during combustion and pyrolysis, main volatile components, flavonoids, and phenolic acids were measured. The results showed that under shading conditions, the stem diameter, leaf width, 5-leaf spacing, branch number, and yield of A. stolonifera decreased significantly, while the plant height, leaf length, leaf number, chlorophyll content, and moxa yield increased first and then decreased with the increase in shading intensity. The burning performance of moxa under natural light was better than that under moderate and severe shading conditions. The content of eucalyptol first increased and then decreased with the increase in shading intensity. The humulene content was negatively correlated with shading intensity. Other major volatile components showed no significant difference under various shading conditions. The content of neochlorogenic acid, cryptochlorogenic acid, isoschaftoside, and isochlorogenic acid B was positively correlated with shading intensity, while the content of chlorogenic acid, isochlorogenic acid A, and isochlorogenic acid C decreased first and then increased with the increase in shading intensity. To sum up, A. stolonifera is a light-loving plant, and shading can greatly reduce the yield, the content of internal components, and the burning performance of moxa. It is the main reason why A. stolonifera is mainly distributed in the forest edge, open forest, roadside, and wasteland grass in the middle and high mountains in the wild. For artificial domestication and cultivation of A. stolonifera, it is better to select plots with sufficient light.

To solve the serious problem of stem and leaf shading in the middle and late stage of traditional flat planting of Codonopsis pilosula, this study analyzed the effects of different stereoscopic traction heights on the photosynthetic characteristics and growth of C. pilosula and explored the optimal traction height to improve the yield and quality of C. pilosula. The experiment designed three stereo-scopic traction heights [H1(60 cm), H2(90 cm), and H3(120 cm)] with natural growth without traction as the control(CK). The results showed that the increase in stereoscopic traction heights broadened the growth space of stems and leaves of C. pilosula, enhanced the ventilation effect, significantly increased the average daily net photosynthetic rate of C. pilosula, promoted the absorption of intercellular CO&#95;2, decreased the transpiration rate, and reduced the evaporation of water. Moreover, it effectively avoided the problem of weakened photosynthesis, maintained the carbon balance of individual plants, and promoted the growth and development of the C. pilosula roots. In terms of the seed yield of C. pilosula, it was ranked as H2&gt;H1&gt;H3&gt;CK. To be specific, H1 increased by 213.41% compared with CK, H2 increased by 282.43% compared with CK, and H3 increased by 133.95% compared with CK. The yield and quality of C. pilosula were the highest in the H3 treatment group, with the fresh yield of 6 858.33 kg·hm~(-2), 50.59% higher than CK, dry yield of 2 398.33 kg·hm~(-2), 76.54% higher than CK, and lobetyolin content of 0.56 mg·g~(-1), 45.22% higher than CK. Therefore, the stereoscopic traction height has a great influence on the photosynthetic characteristics, yield, and quality of C. pilosula. Particularly, the yield and quality of C. pilosula can be optimized and improved in the traction height treatment of H3(120 cm). This planting method is worth popularizing and applying in the cultivated management of C. pilosula.

The leaves of Vernonia amygdalina Delile of the family Asteraceae(also known as &quot;bitter leaf&quot;), rich in biological activities, are used as both medicine and food for a long time in West tropical Africa. They have been introduced into Southeast Asia and Fujian and Guangdong provinces of China in recent years. However, little is known about the properties of the plant in traditional Chinese medicine(TCM), which limits its combination with other Chinese medicinal herbs. In this study, 473 articles on V. amygdalina leaves were selected from PubMed, Web of Science, CNKI, Wanfang Data and VIP to summarize their components, pharmacological effects and clinical research. V. amygdalina leaves presented anti-microbial, hypoglycemic, anti-hypertensive, lipid-lowering, anti-tumor, anti-inflammatory, antioxidant, and other pharmacological effects. On the basis of the theory of TCM properties, the leaves were inferred to be cold in property and bitter and sweet in flavor, acting on spleen, liver, stomach and large intestine and with the functions of clearing heat, drying dampness, purging fire, removing toxin, killing insects and preventing attack of malaria. They can be used to treat dampness-heat diarrhea, interior heat and diabetes, malaria, insect accumulation and eczema(5-10 g dry leaves by decoction per day and an appropriate amount of crushed fresh leaves applying to the affected area for external use). Due to the lack of TCM properties, V. amygdalina leaves are rarely used medicinally in China. The determination of medicinal properties of the leaves is conducive to the introduction of new exotic medicinal herbs and the development of new TCM resources, which facilitated further clinical application and research and development of Chinese medicinal herbs.

Two-dimensional liquid chromatography (2D-LC) has gained increased attention because of its high peak capacity for separating complex samples. However, preparative 2D-LC aimed at isolating compounds is significantly different compared with one-dimensional liquid chromatography (1D-LC) in terms of method development and system configuration; thus, it is less developed than its analytical counterpart. The use of 2D-LC in large-scale product preparation has rarely been reported. Hence, a preparative 2D-LC system was developed in this study. The system was composed of one set of preparative LC modules as a separation system, with a dilution pump, switch valves, and trap column array as the interface, to enable the simultaneous isolation of several compounds. Tobacco was used as a sample, and the developed system was applied to isolate nicotine, chlorogenic acid, rutin, and solanesol. The chromatographic conditions were developed by investigating the trapping efficiency of different types of trap column packings, and chromatographic behaviors under different overload conditions. The four compounds were isolated in one 2D-LC run with high purity. The developed system features low cost because it employs medium-pressure isolation, excellent automation owing to its use of an online column switch, high stability, and capability for large-scale production. The isolation of chemicals from tobacco leaves as pharmaceutical raw materials could aid in the development of the tobacco industry and promote the local agricultural economy.

Phytoremediation plays an important role in the treatment of heavy metal pollution in soil. In order to elucidate the mechanism of salicylic acid (SA) on copper absorption, seedlings from Xuzhou (with strong Cu-tolerance) and Weifang Helianthus tuberosus cultivars (with weak Cu-tolerance) were selected for pot culture experiments. 1 mmol/L SA was sprayed upon 300 mg/kg soil copper stress, and the photosynthesis, leaf antioxidant system, several essential mineral nutrients and the changes of root upon copper stress were analyzed to explore the mechanism of copper resistance. The results showed that Pn , Tr , Gs and Ci upon copper stress decreased significantly compared to the control group. Meanwhile, chlorophyll a, chlorophyll b and carotenoid decreased with significant increase in initial fluorescence ( F 0 ), maximum photochemical quantum yield of PSⅡ ( Fv/Fm ), electron transfer rate (ETR) and photochemical quenching coefficient ( qP ) content all decreased. The ascorbic acid (AsA) content was decreased, the glutathione (GSH) value was increased, the superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activity in the leaves were decreased, and the peroxidase (POD) activity was significantly increased. SA increased the Cu content in the ground and root system, and weakened the nutrient uptake capacity of K, Ca, Mg, and Zn in the root stem and leaves. Spray of exogenous SA can maintain the opening of leaf stomata, improve the adverse effect of copper on photosynthetic pigment and PSⅡ reaction center. Mediating the SOD and APX activity started the AsA-GSH cycle process, effectively regulated the antioxidant enzyme system in chrysanthemum taro, significantly reduced the copper content of all parts of the plant, and improved the ion exchange capacity in the body. External SA increased the content of the negative electric group on the root by changing the proportion of components in the root, promoted the absorption of mineral nutrient elements and the accumulation of osmoregulatory substances, strengthened the fixation effect of the root on metal copper, and avoided its massive accumulation in the H . tuberosus body, so as to alleviate the inhibitory effect of copper on plant growth. The study revealed the physiological regulation of SA upon copper stress, and provided a theoretical basis for planting H . tuberosus to repair soil copper pollution.

GI (GIGANTEA) is one of the output key genes for circadian clock in the plant. The JrGI gene was cloned and its expression in different tissues was analyzed to facilitate the functional research of JrGI . RT-PCR (reverse transcription-polymerase chain reaction) was used to clone JrGI gene in present study. This gene was then analyzed by bioinformatics, subcellular localization and gene expression. The coding sequence (CDS) full length of JrGI gene was 3 516 bp, encoding 1 171 amino acids with a molecular mass of 128.60 kDa and a theoretical isoelectric point of 6.13. It was a hydrophilic protein. Phylogenetic analysis showed that JrGI of 'Xinxin 2' was highly homologous to GI of Populus euphratica . The result of subcellular localization showed that JrGI protein was located in nucleus. The JrGI , JrCO and JrFT genes in female flower buds undifferentiated and early differentiated of 'Xinxin 2' were analyzed by RT-qPCR (real-time quantitative PCR). The results showed that the expression of JrGI , JrCO and JrFT genes were the highest on morphological differentiation, implying the temporal and special regulation of JrGI in the differential process of female flower buds of'Xinxin 2'. In addition, RT-qPCR analysis showed that JrGI gene was expressed in all tissues examined, whereas the expression level in leaves was the highest. It is suggested that JrGI gene plays a key role in the development of walnut leaves.

The present study investigated the chemical constituents from the leaves of Craibiodendron yunnanense. The compounds were isolated and purified from the leaves of C. yunnanense by a combination of various chromatographic techniques including column chromatography over polyamide, silica gel, Sephadex LH-20, and reversed-phase HPLC. Their structures were identified by extensive spectroscopic analyses including MS and NMR data. As a result, 10 compounds, including melionoside F(1), meliosmaionol D(2), naringenin(3), quercetin-3-O-α-L-arabinopyranoside(4), epicatechin(5), quercetin-3'-glucoside(6), corbulain Ib(7), loliolide(8), asiatic acid(9), and ursolic acid(10), were isolated. Compounds 1 and 2 were two new compounds, and compound 7 was isolated from this genus for the first time. All compounds showed no significant cytotoxic activity by MTT assay.

With a large artificial climate chamber, we examined the effects of warming (control, +1.5 ℃, +2.0 ℃), photoperiod (10, 14, 18 h) and nitrogen addition (0, 5, 10, 20 g N·m -2 ·a -1 ) on the main phenological phases of Quercus mongolica in Northeast China. The results showed that 1.5 and 2.0 ℃ warming significantly advanced the bud swelling stage and delayed the leaf fully coloring stage, which prolonged the growing season. The extended days increased with the increases of warming range. Photoperiod significantly affected autumn phenology (leaf coloration onset stage, leaf coloration in general stage, leaf fully coloring stage). Compared with photoperiod of 14 h, short photoperiod (10 h) significantly delayed leaf coloration onset stage by 7.0 d, and prolonged the peak of growth season. Nitrogen addition significantly advanced the bud swelling stage, bud opening stage, first leaf unfolding stage and full leaf unfolding stage. The leaf fully coloring stage was significantly delayed by 9.5 d only at the high nitrogen level of 20 g N·m -2 ·a -1 , indicating that high nitrogen addition prolonged the growing season of Q. mongolica . The synergistic effects of warming and high nitrogen addition (20 g N·m -2 ·a -1 ) significantly delayed the leaf fully coloring stage, which prolonged leaf coloration stage, and the synergistic effects of warming and short photoperiod, the synergistic effects of nitrogen addition and short photoperiod. The synergistic effects of warming, nitrogen addition and short photoperiod all significantly delayed the leaf coloration onset stage, which relatively prolonged the peak of growing season.

Epimedii Folium is a well-known Chinese herbal medicine with the effect of nourishing kidney and strengthening Yang. Its main active ingredients are flavonoids. In this study, 60 samples of Epimedium sagittatum were collected for the determination of total flavonoids(TF) including the total amount of epimedin A, epimedin B, epimedin C, and icariin(abbreviated as ABCI) specified in the Chinese Pharmacopoeia as well as rhamnosylicariside Ⅱ and icariside Ⅱ. The calibration parameters of &quot;first derivativemultiva-riate scattering correction in 1 900-650 cm~(-1) band(4-point smoothing)&quot; and &quot;first derivativestandard normal variable correction in 4 000-650 cm~(-1) full band(4-point smoothing)&quot; were confirmed respectively. The quantitative model was established via Fourier infrared spectroscopy plus attenuated total reflection(FTIR-ATR) accessory combined with partial least squares(PLS) method and then used to predict the flavonoid content of 11 validation sets. The average prediction accuracy for ABCI in calibration set and validation set was 98.985% and 96.087%, respectively. The average prediction accuracy for TF in calibration set and validation set was 98.998% and 94.771%, respectively. These results indicated that FTIR-ATR combined with PLS model could be used for rapid prediction of flavonoid content in E. sagittatum, with the prediction accuracy above 94.7%. The establishment of this method provides a new solution for the detection of a large number of E. sagittatum samples.

Grape ( Vitis vinifera L.) in production is frequently exposed to inadequate light, which significantly affects its agronomic traits via inhibiting their physiological, metabolic and developmental processes. To explore the mechanism how the grape plants respond to the weak light stress, we used 'Yinhong' grape and examined their physiology-biochemistry characteristics and transcriptional profile under different levels of weak light stress. The results showed that grape seedlings upon low intensity shading treatments were not significantly affected. As the shading stress intensity was strengthened, the epidermis cells, palisade tissue, and spongy tissue in the leaves were thinner, the intercellular space between the palisade tissue and spongy tissue was larger compared with that of the control, and the activities of superoxide dismutase, catalase and peroxidase were decreased gradually. Additionally, the soluble protein content increased and the free proline content decreased gradually. Compared with the control, significant changes in plant photosynthetic characteristics and physiology-biochemistry characteristics were observed under high intensity of shading (80%). RNA-seq data showed that the differentially expressed genes between CK and T2, CK and T4, T2 and T4 were 13 913, 13 293 and 14 943, respectively. Most of the enrichment pathways were closely related with the plant's response to stress. Several signaling pathways in response to stress-resistance, e.g. JA/MYC2 pathway and MAPK signal pathway, were activated under weak light stress. The expression level of a variety of genes related to antioxidation (such as polyphenol oxidase and thioredoxin), photosynthesis (such as phytochrome) was altered under weak light stress, indicating that 'Yinhong' grape may activate the antioxidation related pathways to cope with reactive oxygen species (ROS). In addition, it may activate the expression of photosynthetic pigment and light reaction structural protein to maintain the photosynthesis activity. This research may help better understand the relevant physiological response mechanism and facilitate cultivation of grape seedlings under weak light.

Living vegetation volume (LVV) can objectively and accurately reflect the urban greenery quality, and provide a reliable data foundation for the quantitative study aiming to reveal the mechanisms underlying urban greenery ecological functions. According to the characteristics of dispersion and small scale of unit affiliated green space, we proposed a LVV estimation scheme for such urban green space, which included data acquisition, processing, entity segmentation, classification, single tree canopy extraction, and LVV calculation. First, point cloud data was obtained with a backpack LiDAR system, and the ground point clouds were eliminated by a multi-scale algorithm. Second, the Density Based Spatial Clustering of Application with Noise (DBSCAN) algorithm was used to cluster the non-ground point clouds, and density feature-based competitive algorithm was used to re-segmented for the overlapping area to generate independent objects. Third, the PointNet++ network model was used to extracted plant point clouds. Then, the canopy point clouds were extracted using the similarity of principal direction between neighboring points and distribution density of branch and leaf points. Finally, the LVV of individual tree canopy was calculated by the convex hull method, and then the LVV of the accessory greenland was summed up. Taking a science and technology park as an example, its total LVV was 21034.95 m 3 , among which the number of mango trees was the highest, and the total LVV was the largest (4868.64 m 3 , accounting for 23.2%). The tree species with the largest LVV per plant was Terminalia neotaliala tree, with an average of 120.37 m 3 per plant. The relative error between LVV of trees estimated by this scheme compared with traditional method and convex hull method was 10.7%-33.7% and 2.7%-16.0%, with average value of 20.9% and 8.7%, respectively. This scheme could make full use of the characteristics of the three-dimensional point cloud and use a convex polyhedron to simulate the original form of the tree crown, which was more consistent with the actual situation of trees. The measurement and estimation solution of the LVV provided new ideas for rapid and accurate estimation of urban LVV.

In situ measurement of albedo is important for estimating ecosystem energy budget and its remote sensing application. However, the measurement method of albedo on sloping land is limited and the difference in temporal variation in albedo between visible and near-infrared bands remains unclear. Taking a deciduous broad-leaved forest at the Maoershan Forest Ecological Station in Northeast China as an example, we explored the temporal variation and influencing factors of albedo for three bands: incident and reflected solar radiation (SR, 300-2800 nm), photosynthetically active radiation (PAR, 400-700 nm), and near infrared radiation (NIR, 700-2800 nm). The temporal difference in albedo measurements between the two installation methods of radiometers was analyzed. The results showed that, in sunny days, the diurnal variation in SR and NIR albedo had an asymmetric U-shaped curve around the local noon, while PAR increased from sunrise to sunset. In cloudy days, the albedo decreased sharply and then tended to be stable. The measurement with parallel sensors to the slope increased the daily mean value of albedo, but reduced the daily asymmetry of SR and NIR. For the whole growing season, the maximum albedos of SR, NIR and PAR in horizontal measurement were 0.16, 0.27 and 0.11, respectively, and the minimums were 0.07, 0.11 and 0.03, respectively. Albedo in the SR and NIR wavebands increased first and then decreased (the peak value was in July), while PAR showed a contrasting pattern. SR albedo was mainly controlled by NIR rather than PAR. The contribution of the influencing factors was ranked in the order of normalized difference vegetation index (61.7%-78.5%, representing leaf area index) > solar altitude angle (15.4%-36.9%) > clearness index (0.4%-36.9%).

The spatial variation of leaf functional traits in Phragmites australis could reflect the changes of resource allocation. The coupling relationship between leaf functional traits and soil environmental factors represents the ecological adaptation strategies of clonal plants to heterogeneous environments. The research object clonal plant, P. australis , was selected from an inland wetland in northwest China. We examined leaf functional traits of P. australis and their responses to soil environmental factors in wetland, salt marsh, and desert habitats. The results showed that from wetland to desert habitat, foliar contents of C, N and P decreased by 7.2%, 40.0% and 64.1%, respectively, and N and P use efficiency increased, leaf length, leaf width, leaf area, leaf dry weight, specific leaf area and leaf thickness showed a decreasing trend. The coevolution of leaf functional traits was observed, indicating a significant correlation between leaf nutrient elements and specific leaf area. Soil bulk density, salinity, and water availability were the most important environmental factors driving the variation of leaf functional traits of P. australis in wetland, salt marsh and desert habitats, respectively.

Pruning branches and leaves is the measure to stimulate the growth of Lonicera japonica flower buds, and consequently, the resources of pruned leaves are inevitably and seriously wasted in production. High-performance liquid chromatography(HPLC) was applied for content determination of seven active ingredients(chlorogenic acid, galuteolin, isochlorogenic acids A, B, and C, secologanic acid, and secoxyloganin) in L. japonica leaves from March to November. The results showed that the tillering removed from the trunk of L. japonica in March, the leaves pruned from May to July, and the leaves after the first frost date in November were rich in active ingredients, which deserved further exploitation and utilization. The total content(TC) of active ingredients in pruned L. japonica leaves in early March was the highest. The content of active ingredients in L. japonica leaves increased significantly after the first frost date, which was close to that in the bud tillers pruned in early and middle March. After the first frost date, L. japonica leaves are incapable of photosynthesis, and the harvesting of L. japonica leaves does not affect the physiological activities of the tree. In addition to huge resources, the content of active ingredients is high during this period, which is the best harvesting period of L. japonica leaves.

In this study, 10 PA-type Perilla germplasms were selected to detect the content of two phenolic acids, i.e., rosmarinic acid(RA) and caffeic acid(CA), and six flavonoids, including scutellarin-7-O-diglucuronoside(SDG), luteolin-7-O-diglucuronoside(LDG), apigenin-7-O-diglucuronoside(ADG), scutellarin-7-O-glucuroside(SG), luteolin-7-O-glucuroside(LG), and apigenin-7-O-glucuroside(AG) in leaves, stems, and fruits. The total content of phenolic acids and flavonoids in leaves was 3.991-12.028 mg·g~(-1) and 12.309-25.071 mg·g~(-1), respectively, which was much higher than that in stems(0.586-2.015 mg·g~(-1) and 0.879-1.413 mg·g~(-1), respectively) and fruits(0.004-2.222 mg·g~(-1) and 0.651-1.936 mg·g~(-1), respectively). RA was detected in five fruit samples, and RA content between leaves and fruits showed a significant negative correlation in the other five samples. For flavonoids, only LG and LDG could be detected in stems, and SG and SDG were not detected in fruits, while other flavonoids were not detected in some samples. The content of total flavonoids and LG in leaves and fruits was significantly positively correlated, and the content of LG in stems and fruits was significantly positively correlated. In 10 stem samples, seven met the standard that the content of RA in the stem should be not less than 0.1% specified in the Chinese Pharmacopoeia(2020 edition). Only one fruit sample reached the standard of RA content in the fruit not less than 0.25% specified in the Chinese Pharmacopoeia.

Mosses are poikilohydric plants. The duration of leaf spreading time is a key factor affecting their growth and development in the field. The dynamics of field growth and development and influencing factors of mosses in arid and semi-arid areas are largely unknown. In the study, we examined leaf spreading situation under natural conditions from September 5th to November 25th for Didymodon vinealis and Barbula unguiculata , two common species in hilly Loess Plateau. The results showed that the leaves of both species showed a regular diurnal dynamic change of 'spreading-closing-spreading' from September to October, and that the average leaf closing time of D. vinealis in the morning was 0.68 hours earlier than that of B. unguiculata , while leaf spreading time was delayed by 1.79 hours in the afternoon. Both species spread their leaves for longer time in the rainy season. The average leaf spreading duration of D. vinealis was 251 min, which was 30.4% lower than B. unguiculata of 361 min. The relative humidity near the surface was the key factor affecting leaf spreading duration. The morphological structure of moss species would affect leaf spreading duration. Compared with D. vinealis , B. unguiculata was relatively short, with a large proportion of costa in leaves, and the mosaic structure of stem cortex cells was more prominent. The humidity threshold during leaf spreading of B. unguiculata (54.3%) was lower than that of D. vinealis (60.1%). The leaf spreading duration was mainly affected by humidity. B. unguiculata was more adaptable to the environment than D. vinealis .

In this study, we examined the regularity of phenological rhythmical change of plant water-soluble compound δ 13 C (δ 13 C wsc ) in spring for two typical tree species in the warm temperate zone of China, Pinus tabuliformis and Robinia pseudoacacia . The δ 13 C wsc in each organ of those two species in the spring phenological period were measured to explore the relationship between δ 13 C wsc and related environmental factors. The results showed that there were significant differences in δ 13 C wsc values of each organ between P. tabuliformi s and R. pseudoacacia , with higher δ 13 C wsc (-25.03‰±0.01‰) in the new shoot of P. tabuliformis . The δ 13 C wsc value in the non-photosynthetic organs were 0.83‰-1.8‰ higher than that in the photosynthetic organs, while the δ 13 C wsc value in the aboveground part was generally lower than that in the underground part. As spring progressing, different carbon storage strategies were found between two species. When the terminal bud of P. tabuliformis opened, the carbon was obtained from the proximal old leaves. At the beginning of leaf development, photosynthetic products accumulated by old leaves could not meet the growth requirements for new leaves and roots, with 90% of which depending on the carbon reserve in branches and stems. When full leaf having developed, the photosynthetic function of both new and old leaves recovered and the carbon consumed by branches and stems was gradually replenished. For R. pseudoacacia , at the beginning of leaf bud opening and leaf spreading, branches were the main carbon source for new leaves and roots. When leaves were fully unfolded, mature leaves with high capacity of carbon sequestration became the primary carbon source. Results of principal component analysis showed that temperature during observation period, ≥10 ℃ accumulated temperature, sunshine duration and solar radiation were the main factors influencing δ 13 C wsc , which could explained 86.3% of the total variation. The δ 13 C wsc values of both species was negatively correlated with temperature and relative humidity, but positively correlated with the difference of saturated water pressure, ≥10 ℃ accumulated temperature and sunshine duration. The main environmental factors affecting plant δ 13 C wsc varied during the phenological process. Our results could provide a reference for more accurate estimation of spring organ carbon distribution pattern of regional typical tree species, and also a theoretical basis for formulating scientific and reasonable forest management strategy.

Morus alba, a traditional economic crop, is also a significant medicinal plant. The branches(Mori Ramulus), leaves(Mori Folium), roots and barks(Mori Cortex), and fruits(Mori Fructus) of M. alba are rich in chemical components, such as alkaloids, flavonoids, flavanols, anthocyanins, benzofurans, phenolic acids, and polysaccharides, and possess hypoglycemic, hypolipidemic, anti-inflammatory, anti-tumor, anti-microbial, liver protective, immunoregulatory, and other pharmacological activities. This study analyzed the sources, classification, and functions of the main chemical components in M. alba and systematically summarized the latest research results of essential active components in M. alba and their pharmacological effects to provide references for in-depth research and further development as well as utilization of active components in M. alba.

In recent years, the MYB-related gene family has been found pivotal in plant growth and development. MYB-related gene family in Angelica dahurica var. formosana was systematically investigated based on &quot;Chuanzhi No. 2&quot; through transcriptome database search and bioinformatics and the temporal and spatial expression patterns were analyzed through real-time fluorescence-based quantitative polymerase chain reaction(PCR). The results showed that 122 MYB-related proteins family were identified, mainly including the unstable hydrophilic proteins with good thermal stability. Most of the proteins were located in nuclei. The majority of the proteins had the structures of random coil and α-helix. Five MYB-related proteins family of A. dahurica var. formosana had membrane-binding domains. The conserved domain analysis of MYB-related proteins family of A. dahurica var. formosana showed that the MYB domains of genes in five subgroups, similar to 2 R-, 3 R-, and 4 R-MYB proteins, contained three evenly distributed Trp(W) residues in the MYB repeat sequence. The phylogenetic analysis of MYB-related proteins family in A. dahurica var. formosana and Arabidopsis thaliana showed that the MYB-related members were unevenly distributed in five subgroups, and A. thaliana and A. dahurica var. formosana had almost the same number of genes in the CCA1-like subgroup. There were differences in the number, type, and distribution of motifs contained in 122 encoded proteins. Transcription factors with similar branches had similar domains and motifs. The expression pattern analysis showed that the transcription factors AdMYB53, AdMYB83, and AdMYB89 responded to hormones to varying degrees, and they were highly expressed in leaves and responded quickly in roots. This study lays a foundation for further investigating the function of MYB-related transcription factors of A. dahurica var. formosana and solving the corresponding biological problems such as bolting early.

Timing of leaf senescence is important to ensure maize yield. In this study, we investigated the dynamics of carbon and nitrogen balance during leaf senescence in two maize inbred lines PH6WC and PH4CV under normal (4 mmol·L -1 , CK) and low nitrogen (0.04 mmol·L -1 , LN) treatments. Leaf phenotype, photosynthetic characteristics, nitrogen and sugar contents, and carbon to nitrogen ratio of the second and third leaves were analyzed after 2, 4, 6 and 8 days of cultivation. Results showed that leaf size, biomass, relative chlorophyll content, net photosynthetic rate, soluble sugar content, and starch content of the second and third leaves were decreased, while nitrogen production capacity was increased under low nitrogen treatment compared to the control, with the changes of the second leaf being earlier than that of the third leaf. For all the leaf traits, the variation scales of PH6WC were larger than that of PH4CV under low nitrogen stress, and only the C/N ratio in the seedling leaves was significantly increased. In addition, leaf senescence of PH4CV was slower than PH6WC due to its stronger ability in maintaining carbon and nitrogen balance. In conclusion, low nitrogen could induce leaf senescence of maize seedlings. High C/N ratio could promote leaf senescence. There are significant differences in carbon and nitrogen balance ability of seedling leaves between two maize genotypes under low nitrogen stress.

Variations of functional traits with leaf age reflect plant life history strategy and indicate allocation pattern and trade-off characteristics in the limiting resource. In this study, leaves with different ages of Taxus wallichiana var. chinensis saplings were taken as experimental materials. Fourteen leaf functional traits of leaves at three differebt ages were measured in order to reveal changes of the saplings' ecological strategies with leaf aging. The results showed that one-year-old leaves had significantly higher specific leaf area than two- and three-year-old lea-ves, while three-year-old leaves had significantly greater leaf thickness, leaf area, volume, fresh weight and dry weight than leaves at other ages. In addition, one-year-old leaves had significantly greater nitrogen content (N), phosphorus content (P) and N:P than two- and three-year-old leaves, but lower C:N than three-old-year leaves. The slope of allometric relationship between leaf water content and dry weight, leaf thickness and leaf area of one-year-old leaves, leaf thickness and leaf area of three-year-old leaves were all significantly lower than 1.0. Two-year-old leaves showed significantly allometric relationships between many leaf traits, with slope being not equal to 1.0. In conclusion, one-year-old leaves of T. wallichiana var . chinensis saplings tended to have higher photosynthetic capacity, two-year-old leaves had stronger dry matter accumulation, and three-year-old leaves would construct defense system. The coordination and complementation of functional traits among leaves with different ages might have great significance for maintaining individual homeostasis and survival.

Stem photosynthesis ( P g ) is an alternative and significant carbon source, playing a crucial role in plant survival under extreme environment. The main aims of this study were to quantify stem and leaf photosynthesis, find out the main drivers of P g , and estimate the contributions of P g to plant individual carbon balance of two dominant species Haloxylon ammodendron and Tamarix ramosissima in Gurbantunggut Desert. A Li-Cor 6400 portable photosynthesis system and a special chamber were used to measure leaf and stem photosynthesis. Ancillary measurements included leaf/stem functional trait (chlorophyll content, water content, leaf/stem area, carbon/nitrogen content, etc .) and environmental factors (air temperature and humidity, photosynthetically active radiation, soil temperature, and soil water content). Our results showed that P g of H. ammodendron and T. ramosissima was 2.37 and 0.98 μmol·m -2 ·s -1 , P g refixation CO 2 of stem respiration by 65%-76% and 57%-77% in H. ammodendron and T. ramosissima . P g was influenced by photosynthetically active radiation, air temperature, soil temperature and water vapor deficit. P g assimilation CO 2 accounted for 8.2%-16.6% and 3.6%-8.3% of CO 2 assimilation of H. ammodendron and T. ramosissima , respectively. The maximum value appeared at noon when temperature was high. There might be fundamental defects if we ignore the contribution of branch photosynthesis when predicting carbon process of desert ecosystem under the background of climate change.

Water use efficiency (WUE) of five dominant tree species ( Pinus koraiensis , Fraxinus mandshurica , Acer mono , Quercus mongolica , and Tilia amurensis ) was estimated using the stable carbon isotope method in a broadleaved Korean pine forest in Changbai Mountains. Leaf carbon (C), nitrogen (N), and phosphorus (P) contents were measured to analyze nutrient utilization of the dominant species. The relationship between WUE and leaf nutrient contents was systematically assessed. WUE was different due to the variations of micrometeorological factors at different locations in the canopy. The four broadleaved tree species showed upper layer > middle layer > lower layer, while P. koraiensis showed upper layer > lower layer > middle layer. WUE of evergreen coniferous P. koraiensis was higher than that of two broadleaved species with diffuse-porous wood ( T. amurensis and A. mono ) and lower than that of two broadleaved species with ring-porous wood ( F. mandshurica and Q. mongolica ). The compound-leaved species ( F. mandshurica ) had the highest WUE. The WUE of new leaves was significantly higher than old leaves in P. koraiensis . The carbon content and C/N of the old and new leaves of evergreen coniferous P. koraiensis were significantly higher than those of the other four broadleaved tree species, while nitrogen content and N/P were significantly lower than those of the four broadleaved tree species. P content of old leaves of P. koraiensis was significantly lower than that of the four broadleaved tree species. P content of new leaves of current year was not significantly different from that of the broadleaved tree species. The WUE of five tree species had a poor correlation with leaf C content, but a positive correlation with leaf N content. The WUE of evergreen coniferous and deciduous broadleaved tree species was correlated with leaf P content but in opposite direction.

This study was designed to identify the pathogen causing soft rot of Pinellia ternata in Qianjiang of Hubei province and screen out the effective bactericides, so as to provide a theoretical basis for the control of soft rot of P. ternata. In this study, the pathogen was identified based on molecular biology and physiological biochemistry, followed by the detection of pathogenicity and pathogenicity spectrum via plant tissue inoculation in vitro and the indoor toxicity determination using the inhibition zone method to screen out bactericide with good antibacterial effects. The control effect of the bactericide against P. ternata soft rot was verified by the leave and tuber inoculation in vitro. The phylogenetic tree was constructed based on the 16 S rDNA, dnaX gene, and recA gene sequences, respectively, and the result showed that the pathogen belonged to the same branch as the type strain Dickeya fangzhongdai JS5. The physiological and biochemical tests showed that the pathogen was identical to D. fangzhongdai, which proved that the pathogen was D. fangzhongdai. The pathogenicity test indicated that the pathogen could obviously infect leaves at 24 h and tubers in 3 d. As revealed by the indoor toxicity test, 0.3% tetramycin, 5% allicin, and 80% ethylicin had good antibacterial activities, with EC&#95;(50) values all less than 50 mg·L~(-1). Tests in tissues in vitro showed that 5% allicin exhibited the best control effect, followed by 0.3% tetramycin and 10% zhongshengmycin oligosaccharide, and their preventive effects were better than curative effects. Therefore, 5% allicin can be used as the preferred agent for the control of P. ternata soft rot, and 0.3% tetramycin and 10% zhongshengmycin oligosaccharide as the alternatives. This study has provided a certain theoretical basis for the control of P. ternata soft rot.

Oolong tea is a semi-fermented tea with strong flavor, which is widely favored by consumers because of its floral and fruity aroma as well as fresh and mellow taste. During the processing of oolong tea, withering is the first indispensable process for improving flavor formation. However, the molecular mechanism that affects the flavor formation of oolong tea during withering remains unclear. Transcriptome sequencing was used to analyze the difference among the fresh leaves, indoor-withered leaves and solar-withered leaves of oolong tea. A total of 10 793 differentially expressed genes were identified from the three samples. KEGG enrichment analysis showed that the differentially expressed genes were mainly involved in flavonoid synthesis, terpenoid synthesis, plant hormone signal transduction and spliceosome pathways. Subsequently, twelve differentially expressed genes and four differential splicing genes were identified from the four enrichment pathways for fluorescence quantitative PCR analysis. The results showed that the expression patterns of the selected genes during withering were consistent with the results in the transcriptome datasets. Further analysis revealed that the transcriptional inhibition of flavonoid biosynthesis-related genes, the transcriptional enhancement of terpenoid biosynthesis-related genes, as well as the jasmonic acid signal transduction and the alternative splicing mechanism jointly contributed to the flavor formation of high floral and fruity aroma and low bitterness in solar-withered leaves. The results may facilitate better understanding the molecular mechanisms of solar-withering treatment in flavor formation of oolong tea.

Trees are characterized with selective absorption of different forms of nitrogen. Ammonium nitrogen (NH 4 + -N) and nitrate nitrogen (NO 3 - -N) are the main forms of nitrogen for plant absorption. We examined the differences of absorption between NH 4 + -N and NO 3 - -N for 1-year-old Machilus pauhoi seedlings planted in local hilly red soil in a pot experiment. A controlled experiment with 7 different NH 4 + -N/NO 3 - -N treatments was conducted, to study the effects of nitrogen forms and different NH 4 + -N/NO 3 - -N ratios on the growth and leaf traits of M. pauhoi seedlings. The results showed that there were no significant differences in the relative growth rate of ground diameter (GD), plant height (TH), and biomass (RGR) of M. pauhoi seedlings with different NH 4 + -N/NO 3 - -N ratios for four months, but these parameters were relatively high under the treatment of NH 4 + -N:NO 3 - -N=5:5. The seedlings of M. pauhoi didn't show obvious preference for NH 4 + -N and NO 3 - -N in short term. The extremely low NH 4 + -N/NO 3 - -N ratio application was unsuitable for their growth. Different NH 4 + -N/NO 3 - -N application had significant effects on leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC), leaf relative water content (LRWC), net photosynthetic rate ( P n ), intercellular CO 2 concentration ( C i ), water use efficiency (WUE), and photosynthetic nitrogen use efficiency (PNUE). M. pauhoi seedlings under the treatment of NH 4 + -N:NO 3 - -N=1:9 had the highest LA, SLA, P n , WUE and PNUE. However, the seedlings under the treatment of NH 4 + -N:NO 3 - -N=9:1 had the lowest LDMC, leaf tissue density (LTD), LRWC and C i . Different NH 4 + -N/NO 3 - -N combined application did not affect leaf nitrogen content (LN) and leaf phosphorus content (LP), which were highest under the treatment of NH 4 + -N:NO 3 - -N=5:5. Across different NH 4 + -N/NO 3 - -N combined treatments, GD, TH, and RGR were significantly negatively correlated with SLA, while both GD and RGR were significantly negatively correlated with PNUE. Our results could provide theoretical basis for precise nutrient management and high-efficiency cultivation techniques during the seedling stage of the M. pauhoi .

Cambodia is rich in medicinal plant resources. One hundred and thirty-three medicinal material samples, including the hole herb, root, stem/branch, leaf, flower, fruit, seed, and resin, were collected from the Orussey Herbal Market in Phnom Penh, Cambodia, and then authenticated by ITS and psbA-trnH. A total of 46 samples were identified based on ITS sequences, belonging to 24 families, 40 genera, and 42 species. A total of 100 samples were identified by psbA-trnH sequences to belong to 42 families, 77 genera, and 84 species. A total of 103 samples were identified by two DNA barcodes. According to the morphological characteristics of the medicinal materials, 120 samples classified into 50 species, 86 genera, and 86 families were identified, and the majority of them were from Zingiberaceae, Fabaceae, and Acanthaceae. Such samples have been commonly used in traditional Cambodian medicine, Ayurvedic medicine, Unani medicine, traditional Chinese medicine, and ethnomedicine, but different medical systems focus on different functional aspects of the same medicinal material. The results of this study have demonstrated that DNA barcoding has a significant advantage in identifying herbal products, and this study has provided basic data for understanding the traditional medicinal materials used in Cambodia.

The damage mechanism of salt stress on plants has attracted much attention. In order to reveal the damage mechanism of different salt stresses, we compared osmotic regulation and photosynthetic characteristics of seedlings of wheat cultivar Xianhan 3 under sodium salt (150 mmol·L -1 ) and calcium salt (5, 30 mmol·L -1 ) treatments alone or in combination. The results showed that sodium salt or calcium salt stress alone significantly inhibited the growth of roots and stems, but increased the amount of soluble sugar and proline, regulatory energy-dissipated electron yield, non-photochemical quenching and relative content of zeaxanthin contents in leaves. In contrast, salt treatments alone significantly decreased the levels of chlorophyll a and chlorophyll b, maximum photochemical efficiency, PSⅡ photochemical efficiency, photochemical quenching and photosynthetic electron transport efficiency. Furthermore, the inhibition of wheat seedling growth was more sensitive to calcium salt than to sodium salt stress, whereas the decreases of chlorophyll content and chlorophyll fluorescence parameters were more prominent in response to sodium salt stress. Except for the amount of soluble protein, lutein and the relative level of zeaxanthin, the changes of other parameters in the leaves due to sodium salt stress were effectively blocked by the application of low calcium concentration, but further increased by the presence of high calcium salt concentration. Taken together, sodium or calcium salt stress alone significantly inhibited seedling growth. The toxicity of sodium salt to wheat seedlings was effectively alleviated by low calcium concentration, but was aggravated by high calcium concentration, which were associated with the changes of photosynthetic pigment content, light energy capture, and photosynthetic electron transport process in the leaves of wheat seedlings. Moreover, osmotic regulators played an important role in enhancing the resistance of wheat seedlings to sodium or/and calcium environment.

Mechanisms underlying leaf photosynthetic acclimation in winter wheat under elevation of CO 2 concentration ([CO 2 ]) remain unclear. The aim of the study was to investigate the effects of source-sink variation on photosynthetic acclimation induced by drought under elevated [CO 2 ]. A winter wheat ( Triticum aestivum L. 'Zhengmai 9023') pot experiment was conducted in open top climate chambers with [CO 2 ] of 400μmol·mol -1 or 600 μmol·mol -1 and soil water content at 80%±5% or 55%±5% of field capacity. The parameters of chlorophyll fluorescence, electron transport rate, photosynthetic curve, leaf nitrogen content, and grain yield were measured at the elongation and heading stages. Under drought condition, leaf PSⅡ photochemical efficiency was not affected by elevated [CO 2 ], but the maximum electron transport rate and the ratio of electron partitioned to carboxylation reaction in Calvin cycle was increased at the elongation stage, and thus the Rubisco carboxylation rate and maximum photosynthetic rate were increased. Although the maximum electron transportation rate and partitioning ratio of electron to carboxylation reaction in Calvin cycle remained high at the heading stage, the PSⅡ photochemical efficiency, Rubisco carboxylation rate, and triose phosphate utilization rate were decreased by elevated [CO 2 ], which consequently reduced the maximum photosynthetic rate for plant under drought stress. Under drought condition, elevated [CO 2 ] increased wheat tiller biomass, kernel number, and kernel weight per ear, but decreased infertile kernel number, resulting in an overall increase in grain weight. In conclusion, the elevated [CO 2 ]-induced increase in wheat grain yield per tiller under drought condition was mainly caused by enhanced photosynthetic performance at the elongation stage. The photosynthetic acclimation in source leaves during the heading stage under elevated [CO 2 ] was mainly attributed to the reduction in PSⅡ photochemical efficiency and triose phosphate utilization rate, but not to the maximum electron transportation rate, ratio of electron partitioned to carboxylation in Calvin cycle or sink leaf strength.

Soil fauna are important regulators of litter decomposition and nutrient transformation. Nitrogen deposition and rainfall changes driven by global changes could affect litter decomposition by changing environment and soil faunal community. Different mesh size (2 mm and 0.01 mm) litter bags were used to explore how soil meso- and micro-fauna contribute to decomposition of Stipa breviflora litter under nitrogen deposition and rainfall changes. The experiment followed split-plot design, with rainfall change (natural rainfall, CK; rainfall addition 30%, W; rainfall reduction 30%, R) as the main trement and nitrogen addition (0, N 0 ; 30, N 30 ; 50, N 50 ; 100 kg·hm -2 ·a -1 , N 100 ) as the sub-treatment. The results showed that: 1) Rainfall change significantly affected litter decomposition rate, which was increased by rainfall addition. Moreover, litter decomposition rate was accelerated with increasing nitrogen addition rates. Litter residual rate decreased gradually with increasing N addition, and got to the highest in N 100 . Litter decomposition rate decreased first and then increased, and peaked in N 50 in rain reduction and natural rainfall treatment. There was no significant interactions between rainfall change and nitrogen addition in affecting litter decomposition. 2) During the whole decomposition process, a total of 1577 soil meso- and micro-fauna were captured, belonged to 1 phyla, 3 classes, 13 orders (including suborders) and 49 families. The dominant groups were Acarina, Coleoptera larvae, and Collembola. Nitrogen addition significantly increased abundance and group numbers of soil meso- and micro-fauna. 3) The litter mass residue rate was significantly negatively correlated with abundance and group numbers of soil meso- and micro-fauna. The contribution rate of soil meso- and micro-fauna to litter decomposition increased with increasing rainfall. In summary, soil meso- and micro-fauna had a positive effect on decomposition of Stipa breviflora litter in desert steppe. Their contribution to litter was promoted by the enhancement of soil mesofauna abundance and group under rainfall and nitrogen addition. Excessive nitrogen would inhibit soil meso- and micro-fauna community and group density when water was insufficient, and would thus weaken the function of soil mesofauna to litter decomposition.

Ground-level ozone pollution(O 3 ) and climate change have become key global problems threatening the environment and sustainable development of urban forests. At present, various studies have assessed the O 3 impacts on trees; however, it is difficult to accurately evaluate the complex ecological effects caused by multiple factors on the natural urban environment. In this paper, the interactions between O 3 and carbon dioxide(CO 2 ), drought, nitrogen deposition, and warming, as well as the effects of the physiology, biochemistry, and growth of urban trees in China were reviewed. Elevated CO 2 could alleviate the negative effects of elevated O 3 on the photosynthetic metabolism, antioxidant system, and growth of trees. There is a complex interaction between O 3 and drought, which may synergistically aggravate, alleviate, or have no effect on trees. However, there was no correlation between O 3 and N deposition, only a significant interaction between elevated temperatures and O 3 , which slowed down the adverse effects of O 3 on tree growth and photosynthesis. Finally, suggestions are put forward to manage and sustainable develop urban forests in China under future climate change and air pollution.

To explore the effects of carbonized apple branches on cadmium(Cd) accumulation and its damage to apple rootstock, the rootstocks of apple( Malus hupehensis Rehd.) in pots containing soil together with 0.5% and 1%( ω ) carbonized apple branches were irrigated by a nutrient solution containing CdSO 4 . The content of DTPA-Cd(cadmium extracted by diethylenetriamine pentaacetic acid) in the potting soil, and the accumulation of Cd in the roots, stems, and leaves of apple rootstocks, were subsequently monitored. The activities of antioxidant enzymes in roots and leaves, root cell death, and the net photosynthesis rate were further analyzed. The results showed that the concentration of DTPA-Cd in the potting soil with carbonized apple branches was significantly lower than that without carbonized apple branches(Cd-only). Compared with the Cd-only treatment, the concentration of DTPA-Cd in the potting soil decreased by 17.50% and 25.55% in the treatment with 0.5% and 1%( ω ) carbonized apple branches for 12 days. The Cd accumulation in roots, stems, and leaves; the accumulations of superoxide anions(·O 2 - ), hydrogen peroxide(H 2 O 2 ), and malondialdehyde(MDA) in roots and leaves; and the amount of cell death in the roots of apple rootstock treated by carbonized apple branches were significantly lower compared to the Cd-only treatment. However, the activities of superoxide dismutase(SOD), peroxidase(POD), and catalase(CAT) in the roots and leaves, and the net photosynthesis rate of apple rootstock treated by carbonized apple branches, were significantly higher than under the Cd-only treatment. Compared with the Cd-only treatment, Cd accumulation in roots decreased by 29.49% and 37.18% in the treatment with 0.5% and 1%( ω ) carbonized apple branches for 12 days, and the amount of cell death decreased by 22.73% and 29.09%, respectively. Our results show that carbonized apple branches reduce the uptake and accumulation of Cd in apple rootstock by reducing the content of DTPA-Cd in the soil, thereby alleviating the damaging effect of Cd on cells and photosynthesis. Moreover, the use of 1%( ω ) carbonized apple branches was more effective than 0.5%( ω ).