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小麦耕作栽培Wheat Physiology · Biochemistry · Cultivation · Tillage

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For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails Select Wheat growth, photosynthesis and physiological characteristics under different soil Zn levels LI Si-ping, ZENG Lu-sheng, SU Zhong-liang 2022, 21 (7): 1927-1940.   DOI: 10.1016/S2095-3119(21)63643-2 Abstract （259）      PDF in ScienceDirect       In recent years, heavy metal hazards in the soil have seriously affected agricultural production.  This study aims to examine the effects of different levels of heavy metal Zn on the growth, photosynthesis and physiological characteristics of wheat, and provide a theoretical basis for the diagnosis and control of heavy metal pollution in agricultural production.  The field test method was used to explore the changes of wheat agronomic traits, photosynthetic capacity, chlorophyll fluorescence parameters, spectral characteristic curve, active oxygen metabolism system, cell ultrastructure, and yield, under different Zn levels (0, 250, 500, 750, and 1 000 mg kg–1).  The results show that, low-level Zn treatments can effectively promote the synthesis of wheat chlorophyll, improve photosynthetic capacity, and increase yield.  The yield of ZnL1 (250 mg kg–1) was the highest in the two-year test, which increased by 20.4% in 2018 and 13.9% in 2019 compared with CK (0 mg kg–1).  However, a high Zn level had a significant stress effect on the photosystem of wheat.  PIabs (reaction center performance index) and Fv/Fm (maximum photochemical efficiency) were significantly reduced, the active oxygen metabolism system was damaged, and the photosynthetic capacity was reduced, which in turn led to reduced yield.  Among them, the yield of ZnL4 (1 000 mg kg–1) was the lowest in the two-year test, which was 28.1 and 16.4% lower than CK in 2018 and 2019, respectively.  The green peak position of ZnL3 and ZnL4 had “red shift” to the long wave direction, while the red valley position of ZnL4 had “blue shift” to the short wave direction.  Under ZnL4, some wheat leaf organelles began to decompose, vacuoles increased, cytoplasm decreased, cell walls thickened, chloroplast basal lamellae were disordered, and mitochondrial membranes disintegrated.  Stepwise regression and Path analysis showed that Pn (net photosynthetic rate) played a leading role in the formation of yield.  Redundancy (RDA) analysis showed that the optimal Zn level for wheat growth was about 250 mg kg–1, and wheat would be stressed when the soil Zn level exceeded 500 mg kg–1 in the test condition of this study.  Findings of this study provide a theoretical basis for the diagnosis and prevention of heavy metal (Zn) pollution in the soil. Reference | Related Articles | Metrics Select Source–sink relations and responses to sink–source manipulations during grain filling in wheat WU Xiao-li, LIU Miao, LI Chao-su, Allen David (Jack) MCHUGH, LI Ming, XIONG Tao, LIU Yu-bin, TANG Yong-lu 2022, 21 (6): 1593-1605.   DOI: 10.1016/S2095-3119(21)63640-7 Abstract （229）      PDF in ScienceDirect       The source–sink ratio during grain filling is a critical factor that affects crop yield in wheat, and the main objective of this study was to determine the source–sink relations at both the canopy scale and the individual culm level under two nitrogen (N) levels at the post-jointing stage.  Nine widely-used cultivars were chosen for analyzing source–sink relations in southwestern China; and three typical cultivars of different plant types were subjected to artificial manipulation of the grain-filling source–sink ratio to supplement crop growth measurements.  A field experiment was conducted over two consecutive seasons under two N rates (N+, 150 kg ha–1; N–, 60 kg ha–1), and three manipulations were imposed after anthesis: control (Ct), removal of flag and penultimate leaves (Lr) and removal of spikelets on one side of each spike (Sr).  The results showed that the single grain weights in the three cultivars were significantly decreased by Lr and increased by Sr, which demonstrated that wheat grain yield potential seems more source-limited than sink-limited during grain filling, but the source–sink balance was obviously changed by climatic variations and N deficient environments.  Grain yield was highly associated with sink capacity (SICA), grain number, biomass, SPAD values, and leaf area index during grain filling, indicating a higher degree of source limitation with an increase in sink capacity.  Therefore, source limitation should be taken into account by breeders when SICA is increased, especially under non-limiting conditions.  Chuanmai 104, a half-compact type with a mid-sized spike and a long narrow upper leaf, showed relatively better performance in source–sink relations.  Since this cultivar showed the characteristics of a lower reduction in grain weight after Lr, a larger increase after Sr, and a lower reduction in post-anthesis dry matter accumulation, then the greater current photosynthesis during grain filling contributed to the grain after source and sink manipulation.  Reference | Related Articles | Metrics Select Genotype×tillage interaction and the performance of winter bread wheat genotypes in temperate and cold dryland conditions Ebrahim ROOHI, Reza MOHAMMADI, Abdoul Aziz NIANE, Javad VAFABAKHSH, Mozaffar ROUSTAEE, Mohammad Reza JALAL KAMALI, Shahriar SOHRABI, Shahriar FATEHI, Hossain TARIMORADI 2022, 21 (11): 3199-3215.   DOI: 10.1016/j.jia.2022.08.096 Abstract （186）      PDF in ScienceDirect       Growing concerns for food security and the alleviation of hunger necessitate knowledge-based crop management technologies for sustainable crop production.  In this study, 13 winter bread wheat genotypes (old, relatively old, modern, and breeding lines) were evaluated under three different tillage systems, i.e., conventional tillage (CT, full tillage with residue removed), reduced tillage (RT, chisel tillage with residue retained) and no-tillage (NT, no-tillage with residue retained on the soil surface) in farmer’s fields under rainfed conditions using strip-plot arrangements in a randomized complete block design with three replications in the west of Iran (Kamyaran and Hosseinabad locations) over two cropping seasons (2018–2019 and 2019–2020).  The main objectives were to investigate the effects of tillage systems and growing conditions on the agronomic characteristics, grain yield and stability performance of rainfed winter bread wheat genotypes.  Significant (P<0.01) genotype×tillage system interaction effects on grain yield and agronomic traits suggested that the genotypes responded differently to the different tillage systems.  The number of grains per spike and plant height were positively (P<0.0) associated with grain yield under the NT system, so they may be considered as targeted traits for future wheat breeding.  Using statistical models, the modern cultivars (“Sadra” and “Baran”) were identified as high yielding and showed yield stability across the different tillage systems.  As per each tillage system, genotype “Sadra” followed by “Zargana-6//Dari 1-7 Sabalan” exhibited higher adaption to CT; while cultivars “Jam” and “Azar2” showed better performance under the RT system; and cultivars “Varan” and “Baran” tended to have better performance expression in the NT condition.  The increased grain yields achieved in combination with lower costs and greater profits from conservation agriculture suggest that adapted cultivar and NT systems should be evaluated and promoted more widely to farmers in the west of Iran as an attractive package of crop management technologies.  In conclusion, variations in the performance of genotypes and the significant genotype×tillage system interaction effects on grain yield and some agronomic traits assessed in this study suggest that the development and selection of cultivars adapted to the NT system should be considered and included in the strategies and objectives of winter wheat breeding programs for the temperate and cold dryland conditions of Iran. Reference | Related Articles | Metrics Select Analysis of combining ability for stem-related traits and its correlations with lodging resistance heterosis in hybrid wheat YANG Wei-bing, QIN Zhi-lie, SUN Hui, HOU Qi-ling, GAO Jian-gang, CHEN Xian-chao, ZHANG Li-ping, WANG Yong-bo, ZHAO Chang-ping, ZHANG Feng-ting 2022, 21 (1): 26-35.   DOI: 10.1016/S2095-3119(20)63408-6 Abstract （241）      PDF in ScienceDirect       With the application of hybrid wheat, lodging is becoming one of the major factors limiting high yield in its production.  However, few studies have focused on combining ability and heterosis analysis of stem-related traits.  In this study, 24 crosses were made according to NCII genetic design, using the three (photo-sensitive male sterile lines)×eight (restorer lines) incomplete diallel crosses.  The length of basal second internode (LBSI) and breaking strength of basal second internode (BSBSI) as well as other stem-related traits were used to perform the principal component analysis (PCA), combining ability and heterosis analysis.  The PCA results showed that the variables could be classified into two main factors, which were named as the positive factor (factor 1) and the negative factor (factor 2), and accounted for 52.3 and 33.2%, respectively, of the total variance in different variables, combined with the analysis for index weight indicated that the factor 1-related traits play positive roles in lodging resistance formation of hybrids.  Combining ability variance analysis indicated that its genetic performance was mainly dominated by additive gene effects, and the hybrid combinations with higher lodging resistance can be selected by using of 14GF6085 (R1), 14GF6343-2 (R4), 14GF6937 (R6), 14GF7433-1 (R7), and BS1086 (M3), which are with the features with lower general combining ability (GCA) effects of factor 2-related traits whereas higher GCA effects of factor 1-related traits.  The heterosis analysis showed that the wide range of heterosis varied with the traits and combinations, and GCA or specific combining ability (SCA) effects of factor 1-related traits except wall thickness of basal second internode (WTBSI) were positively and closely related to the heterosis of lodging resistance.  Generally, the correlation coefficients of heterosis to GCA effects of sterile lines (GCAm) of factor 1-related traits are significantly higher than that to GCA of restorer lines (GCAr) and SCA, combined with the higher GCAm variance values of factor 1-related traits compared to GCAr, the GCAm of factor 1-related traits should be particularly considered when breeding hybrid combinations.  The heritability analysis showed that the narrow-sense heritability of the diameter of basal second internode (DBSI) and the center of gravity height (TCGH) were obviously lower (<60%) than other traits, suggesting that these two traits were suitable for selection in higher generation for parental breeding.  These could provide a theoretical basis for parental breeding and heterosis utilization of lodging resistance.  Reference | Related Articles | Metrics Select Characteristics of lodging resistance of high-yield winter wheat as affected by nitrogen rate and irrigation managements LI Wen-qian, HAN Ming-ming, PANG Dang-wei, CHEN Jin, WANG Yuan-yuan, DONG He-he, CHANG Yong-lan, JIN Min, LUO Yong-li, LI Yong, WANG Zhen-lin 2022, 21 (5): 1290-1309.   DOI: 10.1016/S2095-3119(20)63566-3 Abstract （278）      PDF in ScienceDirect       High yields of wheat are mainly obtained through a high level of nitrogen and irrigation supplementation.  However, excessive nitrogen and irrigation supplication increase the risk of lodging.  The main objectives of this work were to clarify the capacity of lodging resistance of wheat in response to nitrogen and irrigation, as well as to explore the effective ways of improving lodging resistance in a high-yield wheat cultivar. In this study, field experiments were conducted in the 2015–2016 and 2016–2017 growing seasons.  A wheat cultivar Jimai 22 (JM22), which is widely planted in the northern of Huang-Huai winter wheat region, was grown at Tai’an, Shandong Province, under three nitrogen rates and four irrigation treatments.  The lodging risk was increased with increased nitrogen rate, as indicated by increasing lodging index (LI) and lodging rate across both growing seasons.  With nitrogen increasing, the plant height, the basal internode length and the center of gravity height, which were positively correlated with LI, increased significantly.  While the density of the basal 2nd internode (for culm and leaf sheath) and cell wall component contents, which were negatively correlated with LI, decreased conspicuous along with nitrogen increased.  Increasing irrigation supplementation increased the 2nd internode culm wall thickness, breaking strength and leaf sheath density within limits which increased stem strength.  Among the treatments, nitrogen application at a rate of 240 kg ha–1 and irrigation application at 600 m3 ha–1 at both the jointing and anthesis stages resulted in the highest yield and strongest stem.  A suitable plant height ensures sufficient biomass for high yield, and higher stem stiffness, which was primarily attributed to thicker culm wall, greater density of the culm and leaf sheaths and higher cell wall component contents are the characteristics that should be taken into account to improving wheat lodging resistance. Reference | Related Articles | Metrics Select An economic and viable approach to improve wheat quality in Qinghai–Tibetan Plateau, China WANG Yu-jiao, TAO Zhi-qiang, WANG De-mei, WANG Yan-jie, YANG Yu-shuang, ZHAO Guang-cai, SHI Shu-bing, CHANG Xu-hong 2022, 21 (8): 2227-2240.   DOI: 10.1016/S2095-3119(21)63677-8 Abstract （156）      PDF in ScienceDirect       Wheat flour products are the main dietary component of the Qinghai–Tibetan Plateau (QTP) population in China.  However, the high altitude restricts the local wheat quality and quantity, and the applied nitrogen rate is higher than the optimal rate for wheat planting.  In this study, we considered whether reducing the amount of nitrogen fertilizer and introducing the superior varieties from the North China Plain (NCP) are viable ways to increase the wheat quality and quantity in the QTP.  Three and four winter wheat cultivars from QTP and NCP, respectively, were planted in Lhasa at an altitude of 3 647 m with reduced topdressing nitrogen application at the jointing stage.  The wheat from NCP exhibited higher grain hardness index and test weight, and better flour and dough quality.  Reducing the topdressing nitrogen fertilizer from 135 to 75 kg N ha−1 at the jointing stage (with the same basal fertilization of 105 kg N ha−1) did not significantly (P<0.05) affect the grain yield, grain quality, flour quality or dough quality in any of the cultivars.  In summary, introducing high-quality winter wheat varieties from the NCP to the Lhasa plateau is a viable way to enhance the wheat supply and quality in the QTP.  Reducing a certain amount of the nitrogen fertilizer is an economic and feasible approach for the QTP region. Reference | Related Articles | Metrics Select Effects of sodium benzoate on growth and physiological characteristics of wheat seedlings under compound heavy metal stress LIANG Pan-pan, ZHAO Chen, LIN Yuan, GENG Ji-jia, CHEN Yuan, CHEN De-hua, ZHANG Xiang 2020, 19 (4): 1010-1018.   DOI: 10.1016/S2095-3119(19)62723-1 Abstract （106）      PDF in ScienceDirect       In this study, we investigated the effect of exogenous sodium benzoate on wheat seedlings (Yangmai 16) grown under heavy metal stress.  The results showed that 2.4 mmol kg–1 of heavy metals significantly inhibited growth and delayed emergence of wheat seedlings.  Under compound heavy metal stress, application of 2–4 g L–1 sodium benzoate significantly increased (P<0.01) chlorophyll content and chlorophyll fluorescence parameters Fv/Fm and Fv/Fo of wheat, compared to the control (water treatment).  Further analysis showed that application of 2–4 g L–1 sodium benzoate alleviated osmotic stress by promoting the accumulation of osmolytes such as soluble proteins and free proline, increased the activity of superoxide dismutase (SOD) and reduced malondialdehyde content (MDA).  In contrast, higher concentrations of sodium benzoate solution (>6 g L–1) inhibited the growth of wheat seedlings and even caused damage to seedlings.  Correlation analysis showed that when the sodium benzoate concentration was in the range of 1.97–3.12 g L–1 (2016) and 1.58–3.27 g L–1 (2017), values of chlorophyll and its components, root activity, SOD activity, soluble protein, and free proline content were the highest.  When the sodium benzoate concentration was raised to 2.59 g L–1 (2016) or 3.02 g L–1 (2017), MDA content was the lowest.  Ultimately, exogenous sodium benzoate (2–4 g L–1) facilitates root development and improves the root activity of wheat seedlings grown under compound heavy metals stress, thereby effectively alleviating the damage of compound heavy metal stress in wheat seedlings. Reference | Related Articles | Metrics Select Improved soil characteristics in the deeper plough layer can increase grain yield of winter wheat CHEN Jin, PANG Dang-wei, JIN Min, LUO Yong-li, LI Hao-yu, LI Yong, WANG Zhen-lin 2020, 19 (5): 1215-1226.   DOI: 10.1016/S2095-3119(19)62679-1 Abstract （135）      PDF in ScienceDirect       In the North China Plain (NCP), soil deterioration threatens winter wheat (Triticum aestivum L.) production.  Although rotary tillage or plowing tillage are two methods commonly used in this region, research characterizing the effects of mixed tillage on soil characteristics and wheat yield has been limited.  A fixed-site field trial was carried out during 2011–2016 to examine the impacts of three tillage practices (5-year rotary tillage with maize straw removal (RT); 5-year rotary tillage with maize straw return (RS); and annual RS and with a deep plowing interval of 2 years (RS/DS)) on soil characteristics and root distribution in the plough layer.  Straw return significantly decreased soil bulk density, increased soil organic carbon (SOC) storage and SOC content, macro-aggregate proportion (R0.25) and its stability in the plough layer.  The RS/DS treatment significantly increased the SOC content, total nitrogen (TN), and root length density (RLD) in the 10–40 cm layer, and enhanced the proportion of RLD in the 20–30 and 30–40 cm layers.  In the 20–30 and 30–40 cm layers, an increase in SOC and TN could lead to higher grain production than commensurate increases in the surface layer, resulting in a sustainable increase in grain yield from the RS/DS treatment.  Thus, the RS/DS treatment could lead to high productivity of winter wheat by improving soil characteristics and root distribution at the deeper plough layer in the NCP. Reference | Related Articles | Metrics Select The effects of intraspecific competition and light transmission within the canopy on wheat yield in a wide-precision planting pattern LIU Xin, WANG Wen-xin, LIN Xiang, GU Shu-bo, WANG Dong 2020, 19 (6): 1577-1585.   DOI: 10.1016/S2095-3119(19)62724-3 Abstract （107）      PDF in ScienceDirect       The wide-precision planting pattern has become widely used in the North China Plain as a practice for increasing wheat yield.  However, the effects of tillering development and light transmission within canopy on wheat yield under different sowing widths have not been clearly described.  Therefore, a two-year experiment was conducted, including four different seeding widths (6 cm, W6; 8 cm, W8; 10 cm, W10; 12 cm, W12) and the traditional planting pattern with seeding width of 4 cm (W4).  The results indicated mainly positive effects by the reduced intraspecific competition, specifically all three yield components of W6 and W8 were higher than those for W4.  The configurations with more than 10-cm seeding width were mainly affected by the negative effect of a relative homogeneous canopy, leading to the weakened light transmission, leaf senescence, and reduced grain number per spike.  Finally, the yields of W6 and W8 were significantly higher than that of W4, whereas the yield in W12 was lower (though not significantly) than W4.  In wheat production, therefore, the appropriate seeding width of 6–8 cm is recommended for farmers, whereas the too wide seeding width, with more than 10 cm, should be avoided.   Reference | Related Articles | Metrics Select Heat stability of winter wheat depends on cultivars, timing and protective methods LI Qiang, CHANG Xu-hong, MENG Xiang-hai, LI Ding, ZHAO Ming-hui, SUN Shu-luan, LI Hui-min, QIAO Wen-chen 2020, 19 (8): 1984-1997.   DOI: 10.1016/S2095-3119(19)62760-7 Abstract （146）      PDF in ScienceDirect       Heat stress negatively affects wheat production in many regions of the world.  At present, sensitivity to heat stress remains one of the least understood aspects of wheat genetics and breeding, and measures for preventing heat stress are understudied. In this study, we used three cultivars of winter wheat (GY2018, SL02-1 and SY20) to evaluate the effect of heat stress at different days after anthesis (DAA) on yield and quality.  Heat stability of the cultivars were analyzed and evaluated for the effects of two kinds of regulators on wheat under heat stress conditions.  Heat treatment at 7 DAA led to the most substantial reduction in yield while GY2018 had the best heat stability with respect to yield, and demonstrated the most positive effects on several quality traits including protein content, sedimentation volume and glutenin and gliadin contents.  Heat treatment at 14 DAA had the least reduction in yield, while SY20 had the best heat stability with respect to yield and heat treatment had minimal effects on quality.  Heat treatment at 21 DAA had only a limited effect on yield, while SL02-1 had the best heat stability with respect to yield, but it showed the most negative effects on quality.  Stable time at 14 DAA and protein content at 21 DAA can be used as indicators for detecting the stability of quality under heat stress.  Among the three studied cultivars, SY20 was the most sensitive to heat stress with the stable time decreasing from 26.4 to 9.1 min, a higher sedimentation volume at 7 DAA, and a lower γ-gliadin content which increased 2.4-fold under high-temperature treatment.  The addition of various regulators had different effects: potassium dihydrogen phosphate (KDP) was more protective of yield with heat stress at 7 DAA, while Duntianbao (DTB) had better effects on quality with heat stress at 21 DAA.   Reference | Related Articles | Metrics Select Detection and enumeration of wheat grains based on a deep learning method under various scenarios and scales WU Wei, YANG Tian-le, LI Rui, CHEN Chen, LIU Tao, ZHOU Kai, SUN Cheng-ming, LI Chun-yan, ZHU Xin-kai, GUO Wen-shan 2020, 19 (8): 1998-2008.   DOI: 10.1016/S2095-3119(19)62803-0 Abstract （145）      PDF in ScienceDirect       Grain number is crucial for analysis of yield components and assessment of effects of cultivation measures.  The grain number per spike and thousand-grain weight can be measured by counting grains manually, but it is time-consuming, tedious and error-prone.  Previous image processing algorithms cannot work well with different backgrounds and different sizes.  This study used deep learning methods to resolve the limitations of traditional image processing algorithms.  Wheat grain image datasets were collected in the scenarios of three varieties, six background and two image acquisition devices with different heights, angles and grain numbers, 1 748 images in total.  All images were processed through color space conversion, image flipping and rotation.  The grain was manually annotated, and the datasets were divided into training set, validation set and test set.  We used the TensorFlow framework to construct the Faster Region-based Convolutional Neural Network Model.  Using the transfer learning method, we optimized the wheat grain detection and enumeration model.  The total loss of the model was less than 0.5 and the mean average precision was 0.91.  Compared with previous grain counting algorithms, the grain counting error rate of this model was less than 3% and the running time was less than 2 s.  The model can be effectively applied under a variety of backgrounds, image sizes, grain sizes, shooting angles, and shooting heights, as well as different levels of grain crowding.  It constitutes an effective detection and enumeration tool for wheat grain.  This study provides a reference for further grain testing and enumeration applications.   Reference | Related Articles | Metrics Select The influence of drought stress on malt quality traits of the wild and cultivated barleys HONG Ye, ZHANG Guo-ping 2020, 19 (8): 2009-2015.   DOI: 10.1016/S2095-3119(19)62794-2 Abstract （107）      PDF in ScienceDirect       As a major abiotic stress, drought causes instability and deterioration of malt barley quality.  There is distinct difference among barley cultivars in the responses of the main malt quality traits to drought stress.  In the previous study, we identified some Tibetan wild barley accessions with relatively less change of malt quality traits under drought.  In this study, we examined the impact of drought stress during grain filling stage on grain weight and several important malt quality traits, including total protein content, β-glucan content, limit dextrinase activity, β-amylase activity, and protein fractions in four barley genotypes (two Tibetan wild accessions and two cultivars).  Drought treatment reduced grain weight, β-glucan content, and increased total protein content, β-amylase activity.  These changes differed among barley genotypes and treatments, and are closely associated with grain filling process and kernel weight.  All the results indicated Tibetan wild barley had great potential for developing drought tolerant barley cultivars.  Relatively stable kernel weight or filling process under water stress should be highlighted in malt barley breeding in order to reduce the effect of water stress on malt barley quality.   Reference | Related Articles | Metrics Select Calibration and validation of SiBcrop Model for simulating LAI and surface heat fluxes of winter wheat in the North China Plain CHEN Ying, LIU Feng-shan, TAO Fu-lu, GE Quan-sheng, JIANG Min, WANG Meng, ZHAO Feng-hua 2020, 19 (9): 2206-2215.   DOI: 10.1016/S2095-3119(20)63178-1 Abstract （127）      PDF in ScienceDirect       The accurate representation of surface characteristic is an important process to simulate surface energy and water flux in land-atmosphere boundary layer.  Coupling crop growth model in land surface model is an important method to accurately express the surface characteristics and biophysical processes in farmland.  However, the previous work mainly focused on crops in single cropping system, less work was done in multiple cropping systems.  This article described how to modify the sub-model in the SiBcrop to realize the accuracy simulation of leaf area index (LAI), latent heat flux (LHF) and sensible heat flux (SHF) of winter wheat growing in double cropping system in the North China Plain (NCP).  The seeding date of winter wheat was firstly reset according to the actual growing environment in the NCP.  The phenophases, LAI and heat fluxes in 2004–2006 at Yucheng Station, Shandong Province, China were used to calibrate the model.  The validations of LHF and SHF were based on the measurements at Yucheng Station in 2007–2010 and at Guantao Station, Hebei Province, China in 2009–2010.  The results showed the significant accuracy of the calibrated model in simulating these variables, with which the R2, root mean square error (RMSE) and index of agreement (IOA) between simulated and observed variables were obviously improved than the original code.  The sensitivities of the above variables to seeding date were also displayed to further explain the simulation error of the SiBcrop Model.  Overall, the research results indicated the modified SiBcrop Model can be applied to simulate the growth and flux process of winter wheat growing in double cropping system in the NCP.  Reference | Related Articles | Metrics Select Yield-related agronomic traits evaluation for hybrid wheat and relations of ethylene and polyamines biosynthesis to filling at the mid-grain filling stage YANG Wei-bing, QIN Zhi-lie, SUN Hui, LIAO Xiang-zheng, GAO Jian-gang, WANG Yong-bo, HOU Qi-ling, CHEN Xian-chao, TIAN Li-ping, ZHANG li-ping, MA Jin-xiu, CHEN Zhao-bo, ZHANG Feng-ting, ZHAO Chang-ping 2020, 19 (10): 2407-2418.   DOI: 10.1016/S2095-3119(19)62873-X Abstract （106）      PDF in ScienceDirect       Because of the yield increase of 3.5–15% compared to conventional wheat, hybrid wheat is considered to be one of the main ways to greatly improve the wheat yield in the future.  In this study, we performed a principal component analysis (PCA) on two-line hybrids wheat and their parents using the grain weight (GW), the length of spike (LS), the kernel number of spike (KSN), and spike number (SPN) as variables.  The results showed that the variables could be classified into three main factors, the weight factor (factor 1), the quantity factor 1 (factor 2) and the quantity factor 2 (factor 3), which accounted for 37.1, 22.6 and 18.5%, respectively of the total variance in different agronomic variables, suggesting that the GW is an important indicator for evaluating hybrid combinations, and the grain weight of restorer line (RGW) could be used as a reference for parents selection.  The hybrid combination with a higher score in factor 1 direction and larger mid-parent heterosis (MPH) of the GW and its parents were used to carry out the analysis of grain filling, 1-aminocylopropane-1-carboxylicacid (ACC) and polyamine synthesis related genes.  The results suggested that the GW of superior grain was significantly higher than that of inferior grains in BS1453×JS1 (H) and its parents.  Both grain types showed a weight of H between BS1453 (M) and JS1(R), and a larger MPH, which may be caused by their differences in the active filling stage and the grain filling rate.  The ADP-glucose pyrophosphorylase (AGPase), granule bound starch synthase I (GBSSI), starch synthase III (SSS), and starch branching enzyme-I (SBE-I) expression levels of H were intermediated between M and R, which might be closely related to MPH formation of the GW.  Compared with R and H, the GW of M at maturity was the lowest.  The expression levels of spermidine synthase 2 (Spd2), ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAMDC) had significantly positive correlations with the grain filling rate (r=0.77*, 0.51*, 0.59*), suggesting their major roles in the grain filling and heterosis formation.  These provide a theoretical basis for improving the GW of photo-thermo-sensitive male sterile lines (PTSMSL) by changing the endogenous polyamine synthesis in commercial applications.    Reference | Related Articles | Metrics Select Effects of post-heading high temperature on some quality traits of malt barley NI sheng-jing, ZHAO Hui-fang, ZHANG Guo-ping 2020, 19 (11): 2674-2679.   DOI: 10.1016/S2095-3119(19)62878-9 Abstract （102）      PDF in ScienceDirect       Global change is bringing barley with more frequency of suffering from high temperature.  However, little has been known about the influence of high temperature on malt quality traits.  In this study, we investigated the impact of 1-wk heat stress (32°C/26°C, day/night, 12 h/12 h) initiating from the 7th (HT7) and 14th (HT14) days after heading on some grain and malt quality traits of two barley cultivars.  In comparison with normal temperature (24°C/18°C, day/night, 12 h/12 h), heat stress significantly reduced kernel weight, seed setting rate and grains per spike: HT7 having a larger effect than HT14.  Meanwhile, total protein and β-glucan contents, and β-amylase and limit dextrinase activities were significantly increased under high temperature, with HT7-treated plants showing larger changes.  Moreover, the different changes of four protein fractions under heat stress were found in the two barley cultivars, indicating the possibility of breaking positive association between protein content and enzyme activity. Reference | Related Articles | Metrics Select Changes of oxidative metabolism in the roots of wheat (Triticum aestivum L.) seedlings in response to elevated ammonium concentrations LIU Yang, LI Yu-xiang, LI Yi-xiang, TIAN Zhong-wei, HU Jin-ling, Steve ADKINS, DAI Ting-bo 2021, 20 (5): 1216-1228.   DOI: 10.1016/S2095-3119(20)63216-6 Abstract （157）      PDF in ScienceDirect       To elucidate the response of oxidative metabolism, triggered by elevated ammonium (NH4+) concentrations, on root growth of wheat seedlings, Yumai 49 (NH4+-tolerant) and Lumai 15 (NH4+-sensitive) cultivars were supplied with either 5.0 mmol L–1 NH4+-N (EAC) or 5.0 mmol L–1 NO3–-N (CON) under hydroponic conditions.  Root growth in both cultivars was significantly reduced under EAC, and the negative effect was greater in Lumai 15.  EAC enhanced the activities of monodehydroascorbate reductase and dehydroascorbate reductase in the roots of both cultivars, while it decreased ascorbic acid (ASA) content and GDP-mannose pyrophosphorylase (GMPase) activity at the 12th day after treatment in Lumai 15 by 62.0 and 71.4%; and in Yumai 49 by 38.8 and 62.2%, respectively, indicating that the regeneration of ASA was increased, but the biosynthesis of ASA was reduced under EAC treatment.  Moreover, EAC increased DHA/ASA, reactive oxygen species (ROS), and malondialdehyde contents, as well as antioxidant enzyme activities in the roots of both cultivars.  Relatively greater increases in ROS and soluble sugar, and lower antioxidant enzyme activities in Lumai 15 indicate severe disruption of oxidative metabolism when compared to Yumai 49.  Results reveal that the reduction of ASA biosynthesis via decreased GMPase activity under the EAC condition probably acts as a trigger for accumulated ROS and imbalanced redox status, resulting in root growth inhibition during wheat seedling growth stage.  Yumai 49, being an NH4+-tolerant cultivar, had the stronger capacity to protect itself from oxidative stress, which allowed it to retain a lower DHA to ASA ratio by maintaining a better redox homeostasis than could be maintained in the NH4+-sensitive cultivar Lumai 15. Reference | Related Articles | Metrics Select Physiological response of flag leaf and yield formation of winter wheat under different spring restrictive irrigation regimes in the Haihe Plain, China LIU Xue-jing, YIN Bao-zhong, HU Zhao-hui, BAO Xiao-yuan, WANG Yan-dong, ZHEN Wen-chao 2021, 20 (9): 2343-2359.   DOI: 10.1016/S2095-3119(20)63352-4 Abstract （158）      PDF in ScienceDirect       In order to identify the optimum period of spring water-restrictive irrigation for winter wheat (Triticum aestivum L.) in the Haihe Plain, China and elucidate its effects on flag leaf senescence and yield formation, field experiments were conducted at the Xinji Experimental Station of Hebei Agricultural University from 2016 to 2019 by using different irrigation regimes in spring, including the conventional regime involving two irrigation periods (control (CK), the 3-leaf unfolding stage and the anthesis stage) and a series of single, restrictive irrigation regimes (SRI) comprising irrigation at the 3-leaf unfolding stage (3LI), 4LI, 5LI, and 6LI.  There are five major findings: (1) The senescence (determined by the green leaf area, GLA) in the 4LI treatment occurred moderately earlier than that in CK, showed no significant difference with that in 5LI and 6LI, and occurred significantly later than that in 3LI.  (2) Compared with other SRI treatments, the GLA value and photosynthetic rate in 4LI were 14.82 and 20.1% higher, respectively.  Microstructural analysis of flag leaf also revealed that the mesophyll cells and chloroplasts were irregularly arranged under drought stress in 3LI and 6LI; however, drought stress had minimal negative effects on the microstructure in 4LI and 5LI.  (3) Postponed irrigation in spring could significantly increase superoxide dismutase (SOD) and catalase (CAT) activities in the early stage of grain filling; however, these activities would subsequently decrease.  Among the four SRI treatments, the overall enzyme activities were the highest in 4LI, and the combined malondialdehyde (MDA) content in flag leaves in 4LI and 5LI was 14.5% lower on average than that in 3LI and 6LI.  (4) The soluble sugar (SS) and proline (Pro) contents in 4LI were the highest among the four SRI treatments; however, they were lower than those in CK.  The abscisic acid (ABA) hormone content in 4LI and 5LI was lower than that in 3LI and 6LI, respectively, suggesting a smaller drought stress effect in 4LI and 5LI.  (5) In two growing seasons, there was a larger number of spikes per unit area in 4LI (i.e., 13.4% higher than that in 5LI and 6LI) and the 1 000-grain weight in 4LI was the highest among the four SRI treatments (i.e., 6.0% higher than that in the other three SRI treatments).  Therefore, a single restrictive irrigation regime at the 4-leaf unfolding stage is recommended to be effective in slowing down the senescence process of flag leaves and achieving high yield.   Reference | Related Articles | Metrics Select Impacts of climate change on drought risk of winter wheat in the North China Plain ZHANG Li, CHU Qing-quan, JIANG Yu-lin, CHEN Fu, LEI Yong-deng 2021, 20 (10): 2601-2612.   DOI: 10.1016/S2095-3119(20)63273-7 Abstract （194）      PDF in ScienceDirect       Drought is a major natural disaster causing crop yield losses, while its occurrence mechanism and spatiotemporal variations in a changing climate are still not clear. Based on a long-term climatic dataset (during 1958–2015) from weather stations in the North China Plain (NCP), the influencing mechanism of various climatic factors on drought risk of winter wheat was quantified by using sensitivity analysis, Mann-Kendall trend test and slope estimation. The results indicated that climatic factors have changed considerably over the past six decades in the growth season of winter wheat. As a result, winter wheat suffered from severe droughts (with 350 mm of water deficit during its growth season), particularly at the jointing–heading and heading–mature stages, which were critical to crop yield formation. There were large spatial and temporal variations in drought risk and climatic change factors at different growth stages of winter wheat. Despite precipitation playing a vital role in determining the spatiotemporal patterns of drought risk, high temperature and low humidity along with other climatic factors at key growth stages of winter wheat aggravated drought risk. Particularly, temperature at nearly 90% weather stations showed a notablely upward trend, which exacerbated water deficit and drought risk of winter wheat. Given the complexity and high uncertainty of climate change, these findings provide important information for adapting crop production to future climate change and accompanied droughts while ensuring food security and agricultural sustainability. Reference | Related Articles | Metrics Select Rapid determination of leaf water content for monitoring waterlogging in winter wheat based on hyperspectral parameters YANG Fei-fei, LIU Tao, WANG Qi-yuan, DU Ming-zhu, YANG Tian-le, LIU Da-zhong, LI Shi-juan, LIU Sheng-ping 2021, 20 (10): 2613-2626.   DOI: 10.1016/S2095-3119(20)63306-8 Abstract （224）      PDF in ScienceDirect       Waterlogging is becoming an obvious constraint on food production due to the frequent occurrence of extremely high-level rainfall events.  Leaf water content (LWC) is an important waterlogging indicator, and hyperspectral remote sensing provides a non-destructive, real-time and reliable method to determine LWC.  Thus, based on a pot experiment, winter wheat was subjected to different gradients of waterlogging stress at the jointing stage.  Leaf hyperspectral data and LWC were collected every 7 days after waterlogging treatment until the winter wheat was mature.  Combined with methods such as vegetation index construction, correlation analysis, regression analysis, BP neural network (BPNN), etc., we found that the effect of waterlogging stress on LWC had the characteristics of hysteresis and all waterlogging stress led to the decrease of LWC.  LWC decreased faster under severe stress than under slight stress, but the effect of long-term slight stress was greater than that of short-term severe stress.  The sensitive spectral bands of LWC were located in the visible (VIS, 400–780 nm) and short-wave infrared (SWIR, 1 400–2 500 nm) regions.  The BPNN Model with the original spectrum at 648 nm, the first derivative spectrum at 500 nm, the red edge position (λr), the new vegetation index RVI (437, 466), NDVI (437, 466) and NDVI´ (747, 1 956) as independent variables was the best model for inverting the LWC of waterlogging in winter wheat (modeling set: R2=0.889, RMSE=0.138; validation set: R2=0.891, RMSE=0.518).  These results have important theoretical significance and practical application value for the precise control of waterlogging stress.  Reference | Related Articles | Metrics Select Estimating wheat fractional vegetation cover using a density peak k-means algorithm based on hyperspectral image data LIU Da-zhong, YANG Fei-fei, LIU Sheng-ping 2021, 20 (11): 2880-2891.   DOI: 10.1016/S2095-3119(20)63556-0 Abstract （152）      PDF in ScienceDirect       Fractional vegetation cover (FVC) is an important parameter to measure crop growth.  In studies of crop growth monitoring, it is very important to extract FVC quickly and accurately.  As the most widely used FVC extraction method, the photographic method has the advantages of simple operation and high extraction accuracy.  However, when soil moisture and acquisition times vary, the extraction results are less accurate.  To accommodate various conditions of FVC extraction, this study proposes a new FVC extraction method that extracts FVC from a normalized difference vegetation index (NDVI) greyscale image of wheat by using a density peak k-means (DPK-means) algorithm.  In this study, Yangfumai 4 (YF4) planted in pots and Yangmai 16 (Y16) planted in the field were used as the research materials.  With a hyperspectral imaging camera mounted on a tripod, ground hyperspectral images of winter wheat under different soil conditions (dry and wet) were collected at 1 m above the potted wheat canopy.  Unmanned aerial vehicle (UAV) hyperspectral images of winter wheat at various stages were collected at 50 m above the field wheat canopy by a UAV equipped with a hyperspectral camera.  The pixel dichotomy method and DPK-means algorithm were used to classify vegetation pixels and non-vegetation pixels in NDVI greyscale images of wheat, and the extraction effects of the two methods were compared and analysed.  The results showed that extraction by pixel dichotomy was influenced by the acquisition conditions and its error distribution was relatively scattered, while the extraction effect of the DPK-means algorithm was less affected by the acquisition conditions and its error distribution was concentrated.  The absolute values of error were 0.042 and 0.044, the root mean square errors (RMSE) were 0.028 and 0.030, and the fitting accuracy R2 of the FVC was 0.87 and 0.93, under dry and wet soil conditions and under various time conditions, respectively.  This study found that the DPK-means algorithm was capable of achieving more accurate results than the pixel dichotomy method in various soil and time conditions and was an accurate and robust method for FVC extraction.  Reference | Related Articles | Metrics Select Agronomic management practices in dryland wheat result in variations in precipitation use efficiency due to their differential impacts on the steps in the precipitation use process YANG Wen-jia, LI Yu-lin, LIU Wei-jian, WANG Shi-wen, YIN Li-na, DENG Xi-ping 2023, 22 (1): 92-107.   DOI: 10.1016/j.jia.2022.08.102 Abstract （279）      PDF in ScienceDirect       Yield loss due to low precipitation use efficiency (PUE) occurs frequently in dryland crop production.  PUE is determined by a complicated process of precipitation use in farmland, which includes several sequential steps: precipitation infiltrates into the soil, the infiltrated precipitation is stored in soil, the soil-stored precipitation is consumed through transpiration or evaporation, transpired precipitation is used to produce dry-matter, and finally dry-matter is re-allocated to grains.  These steps can be quantified by six ratios: precipitation infiltration ratio (SW/SWe; SW, total available water; SWe, available soil water storage at the end of a specific period), precipitation storage ratio (SWe/P; P, effective precipitation), precipitation consumption ratio (ET/SW; ET, evapotranspiration), ratio of crop transpiration to evapotranspiration (T/ET; T, crop transpiration), transpiration efficiency (B/T; B, the increment of shoot biomass) and harvest index (Y/B; Y, grain yield).  The final efficiency is then calculated as: PUE=SWe/P×SW/SWe×ET/SW×T/ET×B/T×Y/B.  Quantifying each of those ratios is crucial for the planning and execution of PUE improvements and for optimizing the corresponding agronomic practices in a specific agricultural system.  In this study, those ratios were quantified and evaluated under four integrated agronomic management systems.  Our study revealed that PUE and wheat yield were significantly increased by 8–31% under manure (MIS) or biochar (BIS) integrated systems compared to either conventional farmers’ (CF) or high N (HN) integrated systems.  In the infiltration and storage steps, MIS and BIS resulted in lower SWe/P but higher SW/SWe compared with CF and HN.  Regarding the consumption step, the annual ET/SW under MIS and BIS did not increase due to the higher ET after regreening and the lower ET before regreening compared with CF or HN.  The T/ET was significantly higher under MIS and BIS than under CF or HN.  In the last two steps, transpiration efficiency and harvest index were less strongly affected by the agronomic management system, although both values varied considerably across the different experimental years.  Therefore, attempts to achieve higher PUE and yields in rainfed wheat through agronomic management should focus on increasing the T/ET and SW/SWe, while maintaining ET/SW throughout the year and keeping SWe/P relatively low at harvest time. Reference | Related Articles | Metrics Select Late sowing enhances lodging resistance of wheat plants by improving the biosynthesis and accumulation of lignin and cellulose DONG Xiu-chun, QIAN Tai-feng, CHU Jin-peng, ZHANG Xiu, LIU Yun-jing, DAI Xing-long, HE Ming-rong 2023, 22 (5): 1351-1365.   DOI: 10.1016/j.jia.2022.08.024 Abstract （273）      PDF in ScienceDirect       Delayed sowing mitigates lodging in wheat.  However, the mechanism underlying the enhanced lodging resistance in wheat has yet to be fully elucidated.  Field experiments were conducted to investigate the effects of sowing date on lignin and cellulose metabolism, stem morphological characteristics, lodging resistance, and grain yield.  Seeds of Tainong 18, a winter wheat variety, were sown on October 8 (normal sowing) and October 22 (late sowing) during both of the 2015–2016 and 2016–2017 growing seasons.  The results showed that late sowing enhanced the lodging resistance of wheat by improving the biosynthesis and accumulation of lignin and cellulose.  Under late sowing, the expression levels of key genes (TaPAL, TaCCR, TaCOMT, TaCAD, and TaCesA1, 3, 4, 7, and 8) and enzyme activities (TaPAL and  TaCAD) related to lignin and cellulose biosynthesis peaked 4–12 days earlier, and except for the TaPAL, TaCCR, and TaCesA1 genes and TaPAL, in most cases they were significantly higher than under normal sowing.  As a result, lignin and cellulose accumulated quickly during the stem elongation stage.  The mean and maximum accumulation rates of lignin and cellulose increased, the maximum accumulation contents of lignin and cellulose were higher, and the cellulose accumulation duration was prolonged.  Consequently, the lignin/cellulose ratio and lignin content were increased from 0 day and the cellulose content was increased from 11 days after jointing onward.  Our main finding is that the improved biosynthesis and accumulation of lignin and cellulose were responsible for increasing the stem-filling degree, breaking strength, and lodging resistance.  The major functional genes enhancing lodging resistance in wheat that are induced by delayed sowing need to be determined. Reference | Related Articles | Metrics Select Raised bed planting promotes grain number per spike in wheat grown after rice by improving spike differentiation and enhancing photosynthetic capacity DU Xiang-bei, XI Min, WEI Zhi, CHEN Xiao-fei, WU Wen-ge, KONG Ling-cong 2023, 22 (6): 1631-1644.   DOI: 10.1016/j.jia.2022.08.035 Abstract （364）      PDF in ScienceDirect       The yield of wheat in wheat–rice rotation cropping systems in the Yangtze River Plain, China, is adversely impacted by waterlogging. A raised bed planting (RBP) pattern may reduce waterlogging and increase the wheat yield after rice cultivation by improving the grain number per spike. However, the physiological basis for grain formation under RBP conditions remains poorly understood. The present study was performed over two growing seasons (2018/2019 and 2019/2020) to examine the effects of the planting pattern (i.e., RBP and flat planting (FP)) on the floret and grain formation features and leaf photosynthetic source characteristics of wheat. The results indicated that implementation of the RBP pattern improved the soil–plant nitrogen (N) supply during floret development, which facilitated balanced floret development, resulting in a 9.5% increase in the number of fertile florets per spike. Moreover, the RBP pattern delayed wheat leaf senescence and increased the photosynthetic source capacity by 13.9%, which produced more assimilates for grain filling. Delayed leaf senescence was attributed to the resultant high leaf N content and enhanced antioxidant metabolism. Correspondingly, under RBP conditions, 7.6–8.6% more grains per spike were recorded, and the grain yield was ultimately enhanced by 10.4–12.7%. These results demonstrate that the improvement of the spike differentiation process and the enhancement of the leaf photosynthetic capacity were the main reasons for the increased grain number per spike of wheat under the RBP pattern, and additional improvements in this technique should be achievable through further investigation. Reference | Related Articles | Metrics Select Effects of sowing date and ecological points on yield and the temperature and radiation resources of semi-winter wheat ZHANG Zhen-zhen, CHENG Shuang, FAN Peng, ZHOU Nian-bing, XING Zhi-peng, HU Ya-jie, XU Fang-fu, GUO Bao-wei, WEI Hai-yan, ZHANG Hong-cheng 2023, 22 (5): 1366-1380.   DOI: 10.1016/j.jia.2022.08.029 Abstract （223）      PDF in ScienceDirect       Exploring the effects of sowing date and ecological points on the yield of semi-winter wheat is of great significance.  This study aims to reveal the effects of sowing date and ecological points on the climate resources associated with wheat yield in the Rice–Wheat Rotation System.  With six sowing dates, the experiments were carried out in Donghai and Jianhu counties, Jiangsu Province, China using two semi-winter wheat varieties as the objects of this study.  The basic seedlings of the first sowing date (S1) were planted at 300×104 plants ha−1, which was increased by 10% for each of the delayed sowing dates (S2–S6).  The results showed that the delay of sowing date decreased the number of days, the effective accumulated temperature and the cumulative solar radiation in the whole growth period.  The yields of S1 were higher than those of S2 to S6 by 0.22–0.31, 0.5–0.78, 0.86–0.98, 1.14–1.38, and 1.36–1.59 t ha–1, respectively.  For a given sowing date, the growth days increased as the ecological point was moved north, while both mean daily temperature and effective accumulative temperature decreased, but the cumulative radiation increased.  As a result, the yields at Donghai County were 0.01–0.39 t ha–1 lower than those of Jianhu County for the six sowing dates.  The effective accumulative temperature and cumulative radiation both had significant positive correlations with yield.  The average temperature was significantly negatively correlated with the yield.  The decrease in grain yield was mainly due to the declines in grains per spike and 1 000-grain weight caused by the increase in the daily temperature and the decrease in the effective accumulative temperature. Reference | Related Articles | Metrics Select Tiller fertility is critical for improving grain yield, photosynthesis and nitrogen efficiency in wheat DING Yong-gang, ZHANG Xin-bo, MA Quan, LI Fu-jian, TAO Rong-rong, ZHU Min, Li Chun-yan, ZHU Xin-kai, GUO Wen-shan, DING Jin-feng 2023, 22 (7): 2054-2066.   DOI: 10.1016/j.jia.2022.10.005 Abstract （242）      PDF in ScienceDirect       Genetic improvement has promoted wheat’s grain yield and nitrogen use efficiency (NUE) during the past decades. Therefore, the current wheat cultivars exhibit higher grain yield and NUE than previous cultivars in the Yangtze River Basin, China since the 2000s. However, the critical traits and mechanisms of the increased grain yield and NUE remain unknown. This study explores the mechanisms underlying these new cultivars’ increased grain yield and NUE by studying 21 local cultivars cultivated for three growing seasons from 2016 to 2019. Significantly positive correlations were observed between grain yield and NUE in the three years. The cultivars were grouped into high (HH), medium (MM), and low (LL) grain yield and NUE groups. The HH group exhibited significantly high grain yield and NUE. High grain yield was attributed to more effective ears by high tiller fertility and greater single-spike yield by increasing postanthesis single-stem biomass. Compared to other groups, the HH group demonstrated a longer leaf stay-green ability and a greater flag leaf photosynthetic rate after anthesis. It also showed higher N accumulation at pre-anthesis, which contributed to increasing N accumulation per stem, including stem and leaf sheath, leaf blade, and unit leaf area at preanthesis, and promoting N uptake efficiency, the main contribution of high NUE. Moreover, tiller fertility was positively related to N accumulation per stem, N accumulation per unit leaf area, leaf stay-green ability, and flag leaf photosynthetic rate, which indicates that improving tiller fertility promoted N uptake, leaf N accumulation, and photosynthetic ability, thereby achieving synchronous improvements in grain yield and NUE. Therefore, tiller fertility is proposed as an important kernel indicator that can be used in the breeding and management of cultivars to improve agricultural efficiency and sustainability. Reference | Related Articles | Metrics Select Effect of delayed sowing on grain number, grain weight, and protein concentration of wheat grains at specific positions within spikes CHU Jin-peng, GUO Xin-hu, ZHENG Fei-na, ZHANG Xiu, DAI Xing-long, HE Ming-rong 2023, 22 (8): 2359-2369.   DOI: 10.1016/j.jia.2023.02.002 Abstract （283）      PDF in ScienceDirect       Delays in sowing have significant effects on the grain yield, yield components, and grain protein concentrations of winter wheat.  However, little is known about how delayed sowing affects these characteristics at different positions in the wheat spikes.  In this study, the effects of sowing date were investigated in a winter wheat cultivar, Shannong 30, which was sown in 2019 and 2020 on October 8 (normal sowing) and October 22 (late sowing) under field conditions.  Delayed sowing increased the partitioning of 13C-assimilates to spikes, particularly to florets at the apical section of a spike and those occupying distal positions on the same spikelet.  Consequently, the increase in grain number was the greatest for the apical sections, followed by the basal and central sections.  No significant differences were observed between sowing dates in the superior grain number in the basal and central sections, while the number in apical sections was significantly different.  The number of inferior grains in each section also increased substantially in response to delayed sowing.  The average grain weights in all sections remained unchanged under delayed sowing because there were parallel increases in grain number and 13C-assimilate partitioning to grains at specific positions in the spikes.  Increases in grain number m–2 resulted in reduced grain protein concentrations as the limited nitrogen supply was diluted into more grains.  Delayed sowing caused the greatest reduction in grain protein concentration in the basal sections, followed by the central and apical sections.  No significant differences in the reduction of the grain protein concentration were observed between the inferior and superior grains under delayed sowing.  In conclusion, a 2-week delay in sowing improved grain yield through increased grain number per spike, which originated principally from an increased grain number in the apical sections of spikes and in distal positions on the same spikelet.  However, grain protein concentrations declined in each section because of the increased grain number and reduced N uptake. Reference | Related Articles | Metrics Select Modelling the crop yield gap with a remote sensing-based process model: A case study of winter wheat in the North China Plain YANG Xu, ZHANG Jia-hua, YANG Shan-shan, WANG Jing-wen, BAI Yun, ZHANG Sha 2023, 22 (10): 2993-3005.   DOI: 10.1016/j.jia.2023.02.003 Abstract （237）      PDF in ScienceDirect       Understanding the spatial distribution of the crop yield gap (YG) is essential for improving crop yields.  Recent studies have typically focused on the site scale, which may lead to considerable uncertainties when scaled to the regional scale.  To mitigate this issue, this study used a process-based and remote sensing driven crop yield model for winter wheat (PRYM-Wheat), which was derived from the boreal ecosystem productivity simulator (BEPS), to simulate the YG of winter wheat in the North China Plain from 2015 to 2019.  Yield validation based on statistical yield data revealed good performance of the PRYM-Wheat Model in simulating winter wheat actual yield (Ya).  The distribution of Ya across the North China Plain showed great heterogeneity, decreasing from southeast to northwest.  The remote sensing-estimated results show that the average YG of the study area was 6 400.6 kg ha–1.  The YG of Jiangsu Province was the largest, at 7 307.4 kg ha–1, while the YG of Anhui Province was the smallest, at 5 842.1 kg ha–1.  An analysis of the responses of YG to environmental factors showed no obvious correlation between YG and precipitation, but there was a weak negative correlation between YG and accumulated temperature.  In addition, the YG was positively correlated with elevation.  In general, studying the specific features of the YG can provide directions for increasing crop yields in the future Reference | Related Articles | Metrics Select Combining controlled-release urea and normal urea with appropriate nitrogen application rate to reduce wheat stem lodging risk and increase grain yield and yield stability ZHANG Guang-xin, ZHAO De-hao, FAN Heng-zhi, LIU Shi-ju, LIAO Yun-cheng, HAN Juan 2023, 22 (10): 3006-3021.   DOI: 10.1016/j.jia.2023.02.039 Abstract （223）      PDF in ScienceDirect       A mixture of controlled-release urea and normal urea (CRUNU) is an efficient nitrogen (N) fertilizer type, but little is known about its effects on stem lodging resistance, grain yield, and yield stability of wheat.  In this study, a 4-year field experiment (from 2017 to 2021) was conducted to analyze the effects of N fertilizer types (CRUNU and normal urea (NU)) and application rates (low level (L), 135 kg ha–1; medium level (M), 180 kg ha–1; high level (H), 225 kg ha–1) on population lodging resistance, basal internode strength, lignin content and synthetase activity, stem lodging resistance, grain yield, and yield stability of wheat.  Our results showed that the two N fertilizer types had the highest lodging rate under high N application rates, and the M-CRUNU treatment showed the lowest lodging rate.  Compared with NU, CRUNU improved the wheat population lodging resistance under the three N application rates, mainly related to improving wheat population characteristics and breaking the strength of the second basal internode.  Correlation analysis showed that the breaking strength of the second basal internode was related to the physical characteristics, chemical components, and micro-structure of the internode.  Compared with NU, CRUNU significantly increased wheat grain yield by 4.47, 14.62, and 3.12% under low, medium, and high N application rates, respectively.  In addition, CRUNU showed no significant difference in grain yield under medium and high N application rates, but it presented the highest yield stability under the medium N application rate.  In summary, CRUNU, combined with the medium N application rate, is an efficient agronomic management strategy for wheat production. Reference | Related Articles | Metrics Select No-tillage with straw mulching boosts grain yield of wheat via improving the eco-physiological characteristics in arid regions YIN Wen, FAN Zhi-long, HU Fa-long, FAN Hong, HE Wei, SUN Ya-li, WANG Feng, ZHAO Cai, YU Ai-zhong, CHAI Qiang 2023, 22 (11): 3416-3429.   DOI: 10.1016/j.jia.2023.02.041 Abstract （235）      PDF in ScienceDirect       Straw returning to the field is a technical measure of crop production widely adopted in arid areas.  It is unknown whether crop yield can be further increased by improving the eco-physiological characteristics when straw returning is applied in the crop production system.  So, a three-year field experiment was conducted with various straw returning treatments for wheat production: (i) no-tillage with straw mulching (NTSM), (ii) no-tillage with straw standing (NTSS), (iii) conventional tillage with straw incorporation (CTS), and (iv) conventional tillage with no straw returning (CT, control).  The eco-physiological and yield formation indicators were investigated to provide the basis for selecting the appropriate straw returning method to increase wheat yield and clarifying its regulation mechanism on eco-physiology.  The results showed that NTSM and NTSS treatments had better regulation of eco-physiological characteristics and had a higher yield increase than CTS and CT.  Meanwhile, NTSM had a relatively higher yield than NTSS through better regulation of eco-physiological characteristics.  Compared to CT, the leaf area index of NTSM was decreased by 6.1–7.6% before the Feekes 10.0 stage of wheat, but that of NTSM was increased by 38.9–45.1% after the Feekes 10.0 stage.  NTSM effectively regulated the dynamics of the photosynthetic source of green leaves during the wheat growth period.  NTSM improved net photosynthetic rate by 10.2–21.4% and 11.0–21.6%, raised transpiration rate by 4.4–10.0% and 5.3–6.1%, increased leaf water use efficiency by 5.6–10.4% and 5.4–14.6%, at Feekes 11.0 and 11.2 stages of wheat, compared to CT, respectively.  NTSM had higher leaf water potential (LWP) by 7.5–12.0% and soil water potential (SWP) by 8.9–24.0% from Feekes 10.3 to 11.2 stages of wheat than CT.  Meanwhile, the absolute value of difference on LWP and SWP with NTSM was less than that with CT, indicating that NTSM was conducive to holding the stability of water demand for wheat plants and water supply of soil at arid conditions.  Thus, NTSM had a greater grain yield of wheat by 18.6–27.3% than CT, and the high yield was attributed to the synchronous increase and cooperative development of ear number, grain number per ear, and 1 000-grain weight.  NTSM had a positive effect on regulating the eco-physiological characteristics and can be recommended to enhance wheat grain yield in arid conditions. Reference | Related Articles | Metrics Select Effect of chemical regulators on the recovery of leaf physiology, dry matter accumulation and translocation, and yield-related characteristics in winter wheat following dry-hot wind Yanan Xu, Yue Wu, Yan Han, Jiqing Song, Wenying Zhang, Wei Han, Binhui Liu, Wenbo Bai 2024, 23 (1): 108-121.   DOI: 10.1016/j.jia.2023.04.019 Abstract （238）      PDF in ScienceDirect       Dry-hot wind stress causes losses in wheat productivity in major growing regions worldwide, especially winter wheat in the Huang-Huai-Hai Plain of China, and both the occurrence and severity of such events are likely to increase with global climate change.  To investigate the recovery of physiological functions and yield formation using a new non-commercial chemical regulator (NCR) following dry-hot wind stress, we conducted a three-year field experiment (2018–2021) with sprayed treatments of tap water (control), monopotassium phosphate (CKP), NCR at both the jointing and flowering stages (CFS), and NCR only at the jointing stage (FSJ) or flowering stage (FSF).  The leaf physiology, biomass accumulation and translocation, grain-filling process, and yield components in winter wheat were assessed.  Among the single spraying treatments, the FSJ treatment was beneficial for the accumulation of dry matter before anthesis, as well as larger increases in the maximum grain-filling rate and mean grain-filling rate.  The FSF treatment performed better in maintaining a high relative chlorophyll content as indicated by the SPAD value, and a low rate of excised leaf water loss in flag leaves, promoting dry matter accumulation and the contribution to grain after anthesis, prolonging the duration of grain filling, and causing the period until the maximum grain-filling rate reached earlier.  The CFS treatment was better than any other treatments in relieving the effects of dry-hot wind.  The exogenous NCR treatments significantly increased grain yields by 12.45–18.20% in 2018–2019, 8.89–13.82% in 2019–2020, and 8.10–9.00% in 2020–2021.  The conventional measure of the CKP treatment only increased grain yield by 6.69% in 2020–2021.  The CFS treatment had the greatest mitigating effect on yield loss under dry-hot wind stress, followed by the FSF and FSJ treatments, and the CKP treatment only had a minimal effect.  In summary, the CFS treatment could be used as the main chemical control measure for wheat stress resistance and yield stability in areas with a high incidence of dry-hot wind.  This treatment can effectively regulate green retention and the water status of leaves, promote dry matter accumulation and efficient translocation, improve the grain-filling process, and ultimately reduce yield losses. Reference | Related Articles | Metrics Select The first factor affecting dryland winter wheat grain yield under various mulching measures: Spike number Yingxia Dou, Hubing Zhao, Huimin Yang, Tao Wang, Guanfei Liu, Zhaohui Wang, Sukhdev Malhi 2024, 23 (3): 836-848.   DOI: 10.1016/j.jia.2023.05.034 Abstract （117）      PDF in ScienceDirect       Water is the key factor limiting dryland wheat grain yield.  Mulching affects crop yield and yield components by affecting soil moisture.  Further research is needed to determine the relationships between yield components and soil moisture with yield, and to identify the most important factor affecting grain yield under various mulching measures.  A long-term 9-year field experiment in the Loess Plateau of Northwest China was carried out with three treatments: no mulch (CK), plastic mulch (MP) and straw mulch (MS).  Yield factors and soil moisture were measured, and the relationships between them were explored by correlation analysis, structural equation modeling and significance analysis.  The results showed that compared with CK, the average grain yields of MP and MS increased by 13.0 and 10.6%, respectively.  The average annual grain yield of the MP treatment was 134 kg ha–1 higher than the MS treatment.  There were no significant differences in yield components among the three treatments (P<0.05).  Soil water storage of the MS treatment was greater than the MP treatment, although the differences were not statistically significant.  Soil water storage during the summer fallow period (SWSSF) and soil water storage before sowing (SWSS) of MS were significantly higher than in CK, which increased by 38.5 and 13.6%, respectively.  The relationship between MP and CK was not statistically significant for SWSSF, but the SWSS in MP was significantly higher than in CK.  In terms of soil water storage after harvest (SWSH) and water consumption in the growth period (ET), there were no significant differences among the three treatments.  Based on the three analysis methods, we found that spike number and ET were positively correlated with grain yield.  However, the relative importance of spike number to yield was the greatest in the MP and MS treatments, while that of ET was the greatest in CK.  Sufficient SWSSF could indirectly increase spike number and ET in the three treatments.  Based on these results, mulch can improve yield and soil water storage.  The most important factor affecting the grain yield of dryland wheat was spike number under mulching, and ET with CK.  These findings may help us to understand the main factors influencing dryland wheat grain yield under mulching conditions compared to CK. Reference | Related Articles | Metrics Select Spectral purification improves monitoring accuracy of the comprehensive growth evaluation index for film-mulched winter wheat Zhikai Cheng, Xiaobo Gu, Yadan Du, Zhihui Zhou, Wenlong Li, Xiaobo Zheng, Wenjing Cai, Tian Chang 2024, 23 (5): 1523-1540.   DOI: 10.1016/j.jia.2023.05.036 Abstract （170）      PDF in ScienceDirect       In order to further improve the utility of unmanned aerial vehicle (UAV) remote-sensing for quickly and accurately monitoring the growth of winter wheat under film mulching, this study examined the treatments of ridge mulching, ridge–furrow full mulching, and flat cropping full mulching in winter wheat.  Based on the fuzzy comprehensive evaluation (FCE) method, four agronomic parameters (leaf area index, above-ground biomass, plant height, and leaf chlorophyll content) were used to calculate the comprehensive growth evaluation index (CGEI) of the winter wheat, and 14 visible and near-infrared spectral indices were calculated using spectral purification technology to process the remote-sensing image data of winter wheat obtained by multispectral UAV.   Four machine learning algorithms, partial least squares, support vector machines, random forests, and artificial neural network networks (ANN), were used to build the winter wheat growth monitoring model under film mulching, and accuracy evaluation and mapping of the spatial and temporal distribution of winter wheat growth status were carried out.  The results showed that the CGEI of winter wheat under film mulching constructed using the FCE method could objectively and comprehensively evaluate the crop growth status.  The accuracy of remote-sensing inversion of the CGEI based on the ANN model was higher than for the individual agronomic parameters, with a coefficient of determination of 0.75, a root mean square error of 8.40, and a mean absolute value error of 6.53.  Spectral purification could eliminate the interference of background effects caused by mulching and soil, effectively improving the accuracy of the remote-sensing inversion of winter wheat under film mulching, with the best inversion effect achieved on the ridge–furrow full mulching area after spectral purification.  The results of this study provide a theoretical reference for the use of UAV remote-sensing to monitor the growth status of winter wheat with film mulching. Reference | Related Articles | Metrics Select Heterogeneous population distribution enhances resistance to wheat lodging by optimizing the light environment Yibo Hu, Feng Qin, Zhen Wu, Xiaoqin Wang, Xiaolong Ren, Zhikuan Jia, Zhenlin Wang, Xiaoguang Chen, Tie Cai 2024, 23 (7): 2211-2226.   DOI: 10.1016/j.jia.2023.07.006 Abstract （229）      PDF in ScienceDirect       Lodging is still the key factor that limits continuous increases in wheat yields today, because the mechanical strength of culms is reduced due to low-light stress in populations under high-yield cultivation.  The mechanical properties of the culm are mainly determined by lignin, which is affected by the light environment.  However, little is known about whether the light environment can be sufficiently improved by changing the population distribution to inhibit culm lodging.  Therefore, in this study, we used the wheat cultivar “Xinong 979” to establish a low-density homogeneous distribution treatment (LD), high-density homogeneous distribution treatment (HD), and high-density heterogeneous distribution treatment (HD-h) to study the regulatory effects and mechanism responsible for differences in the lodging resistance of wheat culms under different population distributions.  Compared with LD, HD significantly reduced the light transmittance in the middle and basal layers of the canopy, the net photosynthetic rate in the middle and lower leaves of plants, the accumulation of lignin in the culm, and the breaking resistance of the culm, and thus the lodging index values increased significantly, with lodging rates of 67.5% in 2020–2021 and 59.3% in 2021–2022.  Under HD-h, the light transmittance and other indicators in the middle and basal canopy layers were significantly higher than those under HD, and the lodging index decreased to the point that no lodging occurred.  Compared with LD, the activities of phenylalanine ammonia-Lyase (PAL), 4-coumarate: coenzyme A ligase (4CL), catechol-O-methyltransferase (COMT), and cinnamyl-alcohol dehydrogenase (CAD) in the lignin synthesis pathway were significantly reduced in the culms under HD during the critical period for culm formation, and the relative expression levels of TaPAL, Ta4CL, TaCOMT, and TaCAD were significantly downregulated.  However, the activities of lignin synthesis-related enzymes and their gene expression levels were significantly increased under HD-h compared with HD.  A partial least squares path modeling analysis found significant positive effects between the canopy light environment, the photosynthetic capacity of the middle and lower leaves of plants, lignin synthesis and accumulation, and lodging resistance in the culms.  Thus, under conventional high-density planting, the risk of wheat lodging was significantly higher.  Accordingly, the canopy light environment can be optimized by changing the heterogeneity of the population distribution to improve the photosynthetic capacity of the middle and lower leaves of plants, promote lignin accumulation in the culm, and enhance lodging resistance in wheat.  These findings provide a basis for understanding the mechanism responsible for the lower mechanical strength of the culm under high-yield wheat cultivation, and a theoretical basis and for developing technical measures to enhance lodging resistance. Reference | Related Articles | Metrics Select Twice-split phosphorus application alleviates low-temperature impacts on wheat by improved spikelet development and setting XU Hui, HOU Kuo-yang, FANG Hao, LIU Qian-qian, WU Qiu, LIN Fei-fei, DENG Rui, ZHANG Lin-jie, CHEN Xiang, LI Jin-cai 2023, 22 (12): 3667-3680.   DOI: 10.1016/j.jia.2023.09.013 Abstract （156）      PDF in ScienceDirect       Extreme low-temperature incidents have become more frequent and severe as climate change intensifies.  In Huang-Huai-Hai wheat growing area of China, the late spring coldness occurring at the jointing-booting stage (the anther interval stage) has resulted in significant yield losses of winter wheat.  This study attempts to develop an economical, feasible, and efficient cultivation technique for improving the low-temperature (LT) resistance of wheat by exploring the effects of twice-split phosphorus application (TSPA) on wheat antioxidant characteristics and carbon and nitrogen metabolism physiology under LT treatment at the anther interval stage using Yannong 19 as the experimental material.  The treatments consisted of traditional phosphorus application and TSPA, followed by a –4°C LT treatment and natural temperature (NT) control at the anther interval stage.  Our analyses showed that, compared with the traditional application, the TSPA increased the net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr) of leaves and reduced the intercellular carbon dioxide concentration (Ci).  The activity of carbon and nitrogen metabolism enzymes in the young wheat spikes was also increased by the TSPA, which promoted the accumulation of soluble sugar (SS), sucrose (SUC), soluble protein (SP), and proline (Pro) in young wheat spike and reduced the toxicity of malondialdehyde (MDA).  Due to the improved organic nutrition for reproductive development, the young wheat spikes exhibited enhanced LT resistance, which reduced the sterile spikelet number (SSN) per spike by 11.8% and increased the spikelet setting rate (SSR) and final yield by 6.0 and 8.4%, respectively, compared to the traditional application.  The positive effects of split phosphorus application became more pronounced when the LT treatment was prolonged.   Reference | Related Articles | Metrics Select Transcriptomic and metabolomic analysis of changes in grain weight potential induced by water stress in wheat Yanmei Gao, Maoya Jing, Meng Zhang, Zhen Zhang, Yuqing Liu, Zhimin Wang, Yinghua Zhang 2024, 23 (11): 3706-3722.   DOI: 10.1016/j.jia.2023.12.015 Abstract （142）      PDF in ScienceDirect       The sink strength of developing ovaries in wheat determines the grain weight potential.  The period from booting to the grain setting stage is critical for ovary growth and development and potential sink capacity determination.  However, the underlying regulatory mechanism during this period by which the wheat plant balances and coordinates the floret number and ovary/grain weight under water stress has not been clarified.  Therefore, we designed two irrigation treatments of W0 (no seasonal irrigation) and W1 (additional 75 mm of irrigation at the jointing stage) and analyzed the responses of the ovary/grain weight to water stress at the phenotypic, metabolomic, and transcriptomic levels.  The results showed that the W0 irrigation treatment reduced the soil water content, plant height, and green area of the flag leaf, thus reducing grain number, especially for the inferior grains.  However, it improved the grain weight of the superior and inferior grains as well as average grain weight at maturity, while the average ovary/grain weight and volume during –3 to 10 days after anthesis (DAA) also increased.  Transcriptomic analysis indicated that the genes involved in both sucrose metabolism and phytohormone signal transduction were prominently accelerated by the W0 treatment, accompanied by greater enzymatic activities of soluble acid invertase (SAI) and sucrose synthase (Sus) and elevated abscisic acid (ABA) and indole-3-acetic acid (IAA) levels.  Thus, the sucrose content decreased, while the glucose and fructose contents increased.  In addition, several TaTPP genes (especially TaTPP-6) were down-regulated and the IAA biosynthesis genes TaTAR1 and TaTAR2 were up-regulated under the W0 treatment before anthesis, which further increased the IAA level.  Collectively, water stress reduced the growth of vegetative organs and eliminated most of the inferior grains, but increased the ABA and IAA levels of the surviving ovaries/grains, promoting the enzymatic activity of Sus and degrading sucrose into glucose and fructose.  As a result, the strong sucrose utilization ability, the enhanced enzymatic activity of SAI and the ABA- and IAA-mediated signaling jointly increased the weight and volume of the surviving ovaries/grains, and ultimately achieved the trade-off between ovary/grain weight and number in wheat under water stress. Reference | Related Articles | Metrics Select Effects of water and nitrogen rate on grain-filling characteristics under high-low seedbed cultivation in winter wheat Junming Liu, Zhuanyun Si, Shuang Li, Lifeng Wu, Yingying Zhang, Xiaolei Wu, Hui Cao, Yang Gao, Aiwang Duan 2024, 23 (12): 4018-4031.   DOI: 10.1016/j.jia.2023.12.002 Abstract （220）      PDF in ScienceDirect       A high-efficiency mode of high-low seedbed cultivation (HLSC) has been listed as the main agricultural technology to increase land utilization ratio and grain yield in Shandong Province, China.  However, limited information is available on the optimized water and nitrogen management for yield formation, especially the grain-filling process, under HLSC mode.  A three-year field experiment with four nitrogen rates and three irrigation rates of HLSC was conducted to reveal the response of grain-filling parameters, grain weight percentage of spike weight (GPS), spike moisture content (SMC), and winter wheat yield to water and nitrogen rates.  The four nitrogen rates were N1 (360 kg ha–1 pure N), N2 (300 kg ha–1 pure N), N3 (240 kg ha–1 pure N), and N4 (180 kg ha–1 pure N), respectively, and the three irrigation quotas were W1 (120 mm), W2 (90 mm), and W3 (60 mm), respectively.  Results showed that the determinate growth function generally performed well in simulating the temporal dynamics of grain weight (0.989<R2<0.999, where R2 is the determination coefficient).  The occurrence time of maximum filling rate (Tmax) and active grain-filling period (AGP) increased with the increase in the water or nitrogen rate, whereas the average grain-filling rate (Gmean) had a decreasing trend.  The final 1,000-grain weight (FTGW) increased and then decreased with the increase in the nitrogen rates and increased with the increase in the irrigation rates.  The GPS and SMC had a highly significant quadratic polynomial relationship with grain weight and days after anthesis.  Nitrogen, irrigation, and year significantly affected the Tmax, AGP, Gmean, and FTGW.  Particularly, the AGP and FTGW were insignificantly different between high seedbed (HLSC-H) and low seedbed (HLSC-L) across the water and nitrogen levels.  Moreover, the moderate water and nitrogen supply was more beneficial for grain yield, as well as for spike number and grain number per hectare.  The principal component analysis indicated that combining 240–300 kg N ha–1 and 90–120 mm irrigation quota could improve grain-filling efficiency and yield for the HLSC-cultivated winter wheat.   Reference | Related Articles | Metrics Select Prediction of the potential distribution and analysis of the freezing injury risk of winter wheat on the Loess Plateau under climate change Qing Liang, Xujing Yang, Yuheng Huang, Zhenwei Yang, Meichen Feng, Mingxing Qing, Chao Wang, Wude Yang, Zhigang Wang, Meijun Zhang, Lujie Xiao, Xiaoyan Song 2024, 23 (9): 2941-2954.   DOI: 10.1016/j.jia.2024.02.006 Abstract （80）      PDF in ScienceDirect       Determining the suitable areas for winter wheat under climate change and assessing the risk of freezing injury are crucial for the cultivation of winter wheat.  We used an optimized Maximum Entropy (MaxEnt) Model to predict the potential distribution of winter wheat in the current period (1970–2020) and the future period (2021–2100) under four shared socioeconomic pathway scenarios (SSPs).  We applied statistical downscaling methods to downscale future climate data, established a scientific and practical freezing injury index (FII) by considering the growth period of winter wheat, and analyzed the characteristics of abrupt changes in winter wheat freezing injury by using the Mann-Kendall (M-K) test.  The results showed that the prediction accuracy AUC value of the MaxEnt Model reached 0.976.  The minimum temperature in the coldest month, precipitation in the wettest season and annual precipitation were the main factors affecting the spatial distribution of winter wheat.  The total suitable area of winter wheat was approximately 4.40×107 ha in the current period.  In the 2070s, the moderately suitable areas had the greatest increase by 9.02×105 ha under SSP245 and the least increase by 6.53×105 ha under SSP370.  The centroid coordinates of the total suitable areas tended to move northward.  The potential risks of freezing injury in the high-latitude and -altitude areas of the Loess Plateau, China increased significantly.  The northern areas of Xinzhou in Shanxi Province, China suffered the most serious freezing injury, and the southern areas of the Loess Plateau suffered the least.  Environmental factors such as temperature, precipitation and geographical location had important impacts on the suitable area distribution and freezing injury risk of winter wheat.  In the future, greater attention should be paid to the northward boundaries of both the winter wheat planting areas and the areas of freezing injury risk to provide the early warning of freezing injury and implement corresponding management strategies. Reference | Related Articles | Metrics Select Response of wheat to winter night warming based on physiological and transcriptome analyses Yonghui Fan, Yue Zhang, Yu Tang, Biao Xie, Wei He, Guoji Cui, Jinhao Yang, Wenjing Zhang, Shangyu Ma, Chuanxi Ma, Haipeng Zhang, Zhenglai Huang 2025, 24 (3): 1044-1064.   DOI: 10.1016/j.jia.2024.04.016 Abstract （50）      PDF in ScienceDirect       Global warming is primarily characterized by asymmetric temperature increases, with greater temperature rises in winter/spring and at night compared to summer/autumn and the daytime.  We investigated the impact of winter night warming on the top expanded leaves of the spring wheat cultivar Yangmai 18 and the semi-winter wheat cultivar Yannong 19 during the 2020–2021 growing season.  Results showed that the night-time mean temperature in the treatment group was 1.27°C higher than the ambient temperature, and winter night warming increased the yields of both wheat cultivars, the activities of sucrose synthase and sucrose phosphate synthase after anthesis, and the biosynthesis of sucrose and soluble sugars.  Differentially expressed genes (DEGs) were identified using criteria of P-value<0.05 and fold change>2, and they were subjected to Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses.  Genes differentially expressed in wheat leaves treated with night warming were primarily associated with starch and sucrose metabolism, amino acid biosynthesis, carbon metabolism, plant hormone signal transduction, and amino sugar and nucleotide sugar metabolism.  Comparisons between the groups identified 14 DEGs related to temperature.  These results highlight the effects of winter night warming on wheat development from various perspectives.  Our results provide new insights into the molecular mechanisms of the response of wheat to winter night warming and the candidate genes involved in this process. 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