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Spike length (SL) is one of the most important agronomic traits affecting yield potential and stability in wheat. In this study, a major stable quantitative trait locus (QTL) for SL, i.e., qSl-2B, was detected in multiple environments in a recombinant inbred line (RIL) mapping population, KJ-RILs, derived from a cross between Kenong 9204 (KN9204) and Jing 411 (J411). The qSl-2B QTL was mapped to the 60.06–73.06 Mb region on chromosome 2B and could be identified in multiple mapping populations. An InDel molecular marker in the target region was developed based on a sequence analysis of the two parents. To further clarify the breeding use potential of qSl-2B, we analyzed its genetic effects and breeding selection effect using both the KJ-RIL population and a natural mapping population, which consisted of 316 breeding varieties/advanced lines. The results showed that the qSl-2B alleles from KN9204 showed inconsistent genetic effects on SL in the two mapping populations. Moreover, in the KJ-RILs population, the additive effects analysis of qSl-2B showed that additive effect was higher when both qSl-2D and qSl-5A harbor negative alleles under LN and HN. In China, a moderate selection utilization rate for qSl-2B was found in the Huanghuai winter wheat area and the selective utilization rate for qSl-2B continues to increase. The above findings provided a foundation for the genetic improvement of wheat SL in the future via molecular breeding strategies. Key message: A major stable QTL for spike length was identified in wheat, and its genetic effect on yield related-traits as well as its potential use value in molecular breeding programs were characterized. [ABSTRACT FROM AUTHOR]

The rheological properties and end-use qualities of many foods are mainly determined by the types and levels of grain storage proteins (GSPs) in wheat. GSP levels are influenced by various factors, including tillage management, irrigation, and fertiliser application. However, the effects of irrigation and nitrogen on GSPs remain unclear. To address this knowledge gap, a stationary split–split block design experiment was carried out in low- and high-fertility (LF and HF) soil, with the main plots subjected to irrigation treatments (W0, no irrigation; W1, irrigation only during the jointing stage; W2, irrigation twice during both jointing and flowering stages), subplots subjected to nitrogen application treatments (N0, no nitrogen application; N180, 180 kg/ha; N240, 240 kg/ha; N300, 300 kg/ha), and cultivars tested in sub–sub plots (FDC5, the strong-gluten cultivar Fengdecun 5; BN207, the medium-gluten cultivar Bainong 207). The results showed that GSP levels and processing qualities were significantly influenced by nitrogen application (p < 0.01), N240 was the optimal nitrogen rate, and the influence of irrigation was dependent on soil fertility. Optimal GSP levels were obtained under W2 treatment at LF conditions, and the content was increased by 17% and 16% for FDC5 and BN207 compared with W0 under N240 treatment, respectively. While the optimal GSP levels were obtained under W1 treatments at HF conditions, and the content was increased by 3% and 21% for FDC5 and BN207 compared with W0 under N240 treatment, respectively. Irrigation and nitrogen application increased the glutenin content by increasing Bx7 and Dy10 levels in FDC5, and by increasing the accumulation of Ax1 and Dx5 in BN207. Gliadins were mainly increased by enhancing α/β-gliadin levels. Correlation analysis indicated that a higher soil nitrate (NO3-N) content increased nitrogen remobilisation in leaves. Path analysis showed that Dy10, Dx5, and γ-gliadin largely determined wet glutenin content (WGC), dough stability time (DST), dough water absorption rate (DWR), and sedimentation value (SV). Therefore, appropriate irrigation and nitrogen application can improve nitrogen remobilisation, GSP levels, and processing qualities, thereby improving wheat quality and production. [ABSTRACT FROM AUTHOR]

The objective of this work was to characterize the accumulation of carbon (C) and nitrogen (N), and the translocation of wheat (Triticum aestivum L.) cultivars to achieve both high-quality and high-yield. Twenty-four wheat cultivars, including 12 cultivars containing high-quality gluten subunit 5 + 10 at Glu-D1, and 12 cultivars with no Glu-D1 5 + 10, were planted at Yuanyang and Xuchang in Henan Province, during 2016–2017, and 2017–2018 cropping seasons. Wheat cultivars containing Glu-D1 5 + 10 had an advantage in grain quality traits. Significant difference (P < 0.05) was observed for grain protein concentration (GPC) between 5 + 10 group and no 5 + 10 group. Grain yield (GY) was significantly correlated with kernel number (KN) (r = 0.778, P < 0.01), thousand-kernel weight (TKW) (r = 0.559, P < 0.01), dry matter accumulation at post-anthesis (r = 0.443, P < 0.05), and stem water-soluble carbohydrate (WSC) accumulation (r = 0.487, P < 0.05) and translocation amount (r = 0.490, P < 0.05). GPC, dough stability time (DST) and nitrogen agronomic efficiency (NAE) were significantly correlated with nitrogen accumulation (NAA) at maturity stage (r = 0.524, = 0.404, = 0.418, P < 0.01, < 0.05, < 0.05, respectively), and nitrogen translocation amount (r = 0.512, = 0.471, = 0.405, P < 0.05, < 0.05, < 0.05, respectively). These results suggest that good-quality, high-yield, and high-efficiency could achieve through the selection of high-quality wheat cultivars and coordination of C and N accumulation and translocation. High-quality gluten subunit gene Glu-D1 5 + 10 and stem WSC could be used as a selection index for breeding and production of high-quality and high-yield wheat. [ABSTRACT FROM AUTHOR]

Excessive or improper nitrogen (N) application rates negatively affect crop production and thereby environmental quality, particularly for winter wheat production in the North China Plain. Therefore, it is very important to optimize N fertilizer input to balance grain yield, environmental risk, and benefits under irrigated conditions. Three long-term stationary field experiments including five N levels, from 0 to 300 kg ha-1 [0 (N0), 90 (N90), 180 (N180), 240 (N240), and 300 (N300) kg ha-1] were carried out to investigate the effects of N regime on wheat yield, photosynthesis, and N balance at different sites. The grain yield and protein content increased quadratically with N rate, and the maximum values were 8087 kg ha-1 and 13.9% at N application rates of 250 and 337 kg N ha-1, respectively. N application increased the photosynthetic fluorescence parameters (Pn, Gs, and Tr) and N metabolism enzyme activities (NR and GS) which then increased grain yield. The leaching of soil nitrate into the deeper soil layers (> 100 cm) increased with higher N fertilization and experimental years. The partial factor productivity (PFPN) was decreased by N because the apparent N loss increased with N application rate. In order to balance grain yield, N use efficiency (NUE), and N loss, the recommended N rate should be 120–171 kg N ha-1, and the corresponding yields and apparent N loss were 7278–7787 ka ha-1 and 22–37 kg ha-1, respectively. [ABSTRACT FROM AUTHOR]

Excessive nitrogen (N) application combined with water shortage has a negative effect on crop production, particularly wheat (Triticum aestivum L.) production in the North China Plain. This study examined root growth and water and nitrogen use efficiencies in wheat grown on loam soil in the North China Plain, from 2012 to 2014 using a fixed-position experiment initiated in 2010. The experiment followed a completely randomized split-plot design with four replications, taking irrigation [no irrigation (W0) versus irrigation at jointing plus flowering (W2)] as the main plot and N treatment (0, 180, 240, and 300 kg N ha-1) as the subplot. Compared with W0, W2 increased grain yield and root weight density (RWD) by up to 91.3 and 57.7% in 2012–2013, and 15.5 and 43.0% in 2013–2014, respectively, across all N application rates. Irrigation had no effect on grain water use efficiency (WUEY), but caused a decrease in biomass WUE at vegetative growth stage (WUEF) and at grain-filling stage (WUEM). Significant improvements in grain yield and biomass WUE during vegetative growth stage, and reductions in nitrogen-use efficiency (NUE) and RWD, were observed with increasing N application. Compared with non-N treatment, N treatment increased yield by up to 98.9 and 93.7% in 2012–2013 and 2013–2014, respectively, decreasing RWD by 12.0 and 16.9%. Correlation analysis further revealed that RWD was positively correlated with grain yield, evapotranspiration (ET) and NUE. NUE was also positively correlated with nitrogen uptake efficiency (UPE). Overall, the findings suggest that optimal N application improves NUE by increasing above–ground nitrogen uptake as a result of optimized RWD and a synchronous increase in WUE, thus increasing yield. Under the experimental conditions, an N application rate of 240 kg N ha-1 plus irrigation at jointing and flowering is recommended. [ABSTRACT FROM AUTHOR]

At present, rotary tillage is a conventional farming method in wheat-maize rotation system in North China Plain, however, under the rotary tillage year after year, plough pan tends to become shallow and harden, which results in poor ventilation and drainage, and also is hard to increase grain production, especially in the farmland of lime concretion black soil. Using 'Zhoumai27' as the test material, the field experiment was conducted to research the effects of 3 tillage practices (no tillage, rotary tillage and deep tillage) on grain yield of winter wheat, soil bulk density, soil organic carbon and soil inorganic nitrogen, in order to select the appropriate tillage practices and further improve the potential of grain production in the farmland of lime concretion black soil. The results showed: 1) In terms of soil bulk density, there were no significant differences among 3 tillage treatments in 0-10 cm soil layer during wheat growth period, and also no differences at maturity period of wheat in >30-40 cm soil layer, but deep tillage practice could significantly decrease (P<0.05) soil bulk density in >10-30 cm soil layer compared with no tillage. 2) There were no significant differences among 3 tillage practices in 0-20 cm soil layer, but deep tillage could increase (P<0.05) the content of soil organic carbon in >20-40 cm soil layer compared with no tillage. 3) In 0-20 cm soil layer, compared with no tillage or deep tillage, rotary tillage significantly increased (P<0.05) the contents of nitrate nitrogen in the seedling, wintering and anthesis period of winter wheat. However, the content of nitrate nitrogen at jointing stage did not reach significant difference among 3 treatments, and was significantly higher (P<0.05) under no tillage than under rotary tillage and deep tillage at maturity of wheat. In >20-40 cm soil layer, the higher content of nitrate nitrogen was detected in rotary tillage in seedling and anthesis period, and no tillage was higher at other growth stages of winter wheat. 4) In terms of the content of ammonium nitrogen in soil, in 0-20 cm soil layer, during the seedling, wintering and anthesis period of winter wheat there were no significant differences between rotary tillage and deep tillage, but no tillage showed higher values. At jointing stage, the order of the content of ammonium nitrogen was rotary tillage > deep tillage > no tillage, and also there was significant differences among 3 tillage treatments (P<0.05), but at maturity stage, the content of ammonium nitrogen in 3 treatments did not reach significant differences. In >20-40 cm soil layer, the order of the content of ammonium nitrogen was deep tillage > rotary tillage > no tillage during the whole growth period of winter wheat. 5) Compared with no tillage, deep tillage could significantly increase (P<0.05) grain yield of winter wheat mainly, for deep tillage increased 1000-grain weight and grain number. To sum up, under the condition of our field experiment, deep tillage could decrease soil bulk density in >10-30 cm soil layer, improve the content of organic carbon and ammonium nitrogen in >20-40 cm soil layers, and also increase grain yield of winter wheat in the end. Therefore, deep tillage practice should be selected as an appropriate tillage practice in the farmland of lime concretion black soil. [ABSTRACT FROM AUTHOR]

High temperature (HT) and drought stress (DS) pose serious limitations to wheat ( Triticum aestivum L.) grain development, which strongly influences grain yield and quality. In this study, we investigated changes in starch characteristics and starch granules of the high-yielding winter wheat cultivar Zhengmai 366 in response to HT and DS, both alone and in combination. HT, DS and the combination of these stressors led to a significant reduction in the proportion of A-type starch granules (>9.9 µm) to B-type starch granules (<9.9 µm), and the effects of HT and DS were significantly additive. The volume proportion of A-type starch granules (>9.9 µm) was positively correlated with the contents of AM, AP and starch as well as the grain yield (thousand grains weight) and was negatively correlated with the ratio of AM to AP, whereas there was a contrary correlation between the volume proportion of B-type starch granules (<9.9 µm) and these values. HT, DS and HT plus DS led to a significant reduction in the content of AP and starch and grain yield, but these treatments had less of an impact on AM content. DS reduced the size of the small starch granules, while HT reduced the size of the large granules. The changes in morphology and size distribution of starch granules led to a reduction in starch content under both stress conditions, consequently reducing grain yield. HT plus DS had a much greater influence on starch characteristics and yield than HT or DS alone. [ABSTRACT FROM AUTHOR]

As the growing population and the environment deterioration worldwide, it is a great challenge to explore how to use the available cropland and resource to feed more people with less environmental cost. Here, we performed a planting survey about winter wheat involving 1496 smallholders across the Huang-Huai-Hai Region. Based on this survey, we summarized the farmers' cultivation pattern (FP). By water and fertilizer coupling effects, we proposed a lower carbon-emission pattern (T1) and an equal carbon-emission pattern (T2). FP treatment included 270–330 kg ha−1 nitrogen (N), 120 kg ha−1 P 2 O 5 , 120 kg ha−1 K 2 O and irrigated once - three times; T1 treatment included 180–240 kg ha−1 N, 120 kg ha−1 P 2 O 5 , 80–120 kg ha−1 K 2 O, 0–15 kg ha−1 ZnSO 4 and irrigated once - twice; T2 treatment included 240–300 kg ha−1 N, 120–180 kg ha−1 P 2 O 5 , 120–150 kg ha−1 K 2 O, 15–30 kg ha−1 ZnSO 4 and irrigated once - three times. A 4-year cultivation experiment was conducted in 10 cities. The results showed that T1 and T2 treatments exhibited similar positive effects in promoting sustainable intensification in the region compared with FP. Compared with FP treatment, T1 and T2 increased the yields by 10.0% and 19.6%, water use efficiency by 19.8% and 15.2%, and partial factor productivity from applied N by 48.4% and 20.4% in the region, respectively; meanwhile, T1 treatment decreased carbon emissions by 25.2%. The yield of T1 and T2 treatments was higher than that of FP, mainly due to increased spike number, dry matter accumulation, and harvest index, which may be affected by the lower proportion of nitrogen fertilizer in the applied water and fertilizer. To facilitate sustainable intensification in the region, encouraging local farmers to adjust applied nutrients and water structures for lower carbon emissions will be a universal orientation. This research provides a reference for other similar regions. • The trial design was based on a survey of 1496 smallholders. • Adjusting applied water and fertilizer structure is a way to control carbon emissions. • Water and fertilizer coupling can promote wheat sustainable intensification. • Two effective wheat cultivation patterns at regional scale were proposed. [ABSTRACT FROM AUTHOR]

• The wavelet feature potential is enormous in estimating CCC under multiple stressors. • RFR and SVR models are applicable to the data of N and PM stress, respectively. • CWT-CARS-VIF-SVR mode is promising for CCC estimation under multiple stressors. As an important indicator of the photosynthetic capacity of crops, the canopy chlorophyll content (CCC) is nondestructively estimated by reflectance using various spectrometers. Crop growth is often severely affected by Nitrogen (N) deficiency and diseases, and the compatibility of the data collected for different stressors needs further clarification to develop unified estimation models. In this field experimental study, hyperspectral data of the wheat canopy were collected, along with canopy chlorophyll content, to assess nitrogen deficiency and powdery mildew stress. Comparative analysis of hyperspectral remote sensing data input features (original reflectance (OR), spectral index (SI) and wavelet features (WF)) was conducted. A combination of feature selection and machine learning was used to determine the best estimation mode for the accurate inversion of CCC under these two stressors. The results showed that the canopy spectra under nitrogen deficiency and powdery mildew stress had the same change trend. Under nitrogen deficiency, the sensitive wavelengths to CCC mainly reflected canopy structure characteristics, followed by pigments. Under powdery mildew stress, the sensitive wavelengths mainly reflected pigment characteristics, followed by canopy structure. Eight input features (two reflectance wavelengths, two spectral indices and four wavelet features) were selected using competitive adaptive reweighted sampling (CARS) and variance inflation factor (VIF) methods. Machine learning (ML) produced better estimates for both stressors. For CCC estimation under nitrogen stress, random forest regression (RFR) was more suitable (R2 = 0.828; RMSE = 0.363 g/m2) and showed a higher accuracy for both the calibration and validation sets. For CCC estimation under powdery mildew stress, support vector machine regression (SVR) was more suitable (R2 = 0.787; RMSE = 0.126 g/m2), especially when OR and WF data were used as input features. For the unified estimation of CCC under both stressors, WF is most effective as an input feature and good accuracy is achieved for both SVR (R2 = 0.846; RMSE = 0.296 g/m2) and RFR (R2 = 0.844; RMSE = 0.297 g/m2), and their differences are very small. The results demonstrated that the CWT-CARS-VIF-ML mode was appropriate for CCC estimation under two different stressors, which provides an ideal reference and technical guidance for the evaluation of photosynthetic potential and improved crop management. [ABSTRACT FROM AUTHOR]

Glutamine synthetase (GS) plays a central role in plant nitrogen (N) metabolism, which improves crops grain protein content. A pot experiment in field condition was carried out to evaluate GS expression and activity, and grain protein content in high (Wanmai16) and low grain protein (Loumai24) wheat cultivars under two N levels (0.05 and 0.15 g N kg −1 soil). High nitrogen (HN) resulted in significant increases in GS1 and GS2 expression at 10 days after anthesis (DAA), and higher GS activity during the entire grain filling stage. HN also significantly increased yield, grain protein content and protein fraction (except for glutenin of Luomai24) in two wheat cultivars, which indicated that it increased grain yield and protein content by improving nitrogen metabolism. Wanmai16 showed higher grain protein content, gliadin and glutenin content, and had higher expression level of GS2 both in flag leaves and grains at early grain filling stage. However, Luomai24 had greater yield and higher expression level of GS1 . The difference expression of GS2 and GS1 genes indicates they had various contributions to the accumulation of protein and starch in wheat grains, respectively. The results suggest that GS2 would be serving as a potential breeding target for improving wheat quality. [ABSTRACT FROM AUTHOR]

The number of grains per unit land area is the most important component to determine grain yield in wheat. Survival of floret primordia seems to be critical for the determination of grain number, which is related to the number of fertile florets at anthesis and the growth of the florets have been frequently considered the determinant key to establish grain number. The objective of this study was to explore the dynamics pattern of floret generation/degeneration/abortion and the grain setting characteristics in winter wheat under contrasting conditions of foliar spraying. Field experiments were carried out during the 2011–2012 and 2012–2013 growing seasons at the Experiment Station of Henan Agricultural University. The experiment involved the wheat cultivar Yumai 49-198 and three foliar applications; water, 6-benzylaminopurine (6-BA), and boron, which were applied 25 days after the jointing stage. This study analysed in detail floret development in wheat as affected by resource availability (mainly foliar spraying), and found that the degeneration rates of the basal spikelet florets decreased by 24% and 6%, respectively, following application of 6-BA and boron. Similarly, the floret abortion rates were reduced by 73% (6-BA) and 22% (boron) when compared to the water control. The degeneration rates of florets from central spikelets decreased by 15% and 8%, after treatment with 6-BA and boron, respectively, while the abortion rates were reduced by 76% and 44%, respectively, when compared to the control. Spraying 6-BA significantly enhances the process by which florets became grains at different floret and spikelet positions, and especially promoted the grain setting of distal florets, respect to the rachis, into the spikelets ( i.e ., Florets 3 and 4). [ABSTRACT FROM AUTHOR]

Highlights: [•] Optimized cultivation patterns enhance the growth of roots in the middle and lower soil layers. [•] Roots in the middle and lower soil layers play important role in grain yields. [•] Optimized cultivation patterns increase water and fertilizer efficiency and grain yields. [ABSTRACT FROM AUTHOR]

Abstract: D-myo-Inositol-3-phosphate (D-Ins(3)P1) synthase (MIPS EC 5.5.1.4) catalyzes the first step in the phytic acid biosynthetic pathway. To understand the function of the MIPS gene and phytic acid accumulation, the TaMIPS gene was characterized, and changes in gene expression and MIPS activity were analyzed. The full-length genomic DNA sequence of the TaMIPS gene, located in homologous group 4 chromosomes, was characterized. TaMIPS comprises ten exons and nine introns, with 3910 bp in total, with a cDNA open reading frame (ORF) of 1533 bp encoding a protein with 510 amino acids. The transcription of this gene was detected in roots, stems, flag leaves and immature seeds at 15 day after flowering (DAF), and high levels of gene transcripts were detected in immature seeds at 14 DAF. The enzymatic activity of MIPS was found to be high before 14 DAF, followed by a gradual reduction until seed maturity. The phytic acid concentration also gradually increased with seed maturity. A wheat cultivar with a high phytic acid content had higher enzymatic activity and higher levels of expression of MIPS than did a cultivar with low phytic acid content. The results show that the TaMIPS gene may play an important role in regulating phytate synthesis. [Copyright &y& Elsevier]