Cyclic nucleotide-gated ion channels are ligand-gated cationic channels that exist in animals and plants, which are an important part of eukaryotic signaling cascades. In this study, OsCNGC10 (cyclic nucleotide-gated channel) gene in rice was used, and the overexpression vector pU1301-CNGC10-Flag and the double-target knockout vector pRGEB32-CRISPR/cas9-cngc10 were constructed. The knockout and overexpression materials were obtained by Agrobacterium-mediated genetic transformation. Homozygous plants oscngc10-2 and OE-CNGC10-6 were isolated from T₂ generation. The analysis of stem characteristics and lodging resistance of transgenic plants showed that oscngc10-2 had enhanced stem strength and lodging resistance. Stem cell wall sections and tissue composition analysis showed that oscngc10-2 increased lodging resistance due to the increase of stem wall thickness, parenchyma cell abundance, and lignin content. The knockout of OsCNGC10 increased the lignin content and the abundance of stem-cell wall parenchyma cells. The overexpression of OsCNGC10 reduced stem wall thickness, lignin content, and cell abundance in stem cell wall, while the knockdown of OsCNGC10 increased lignin content and increased the abundance of thin-walled cells in stem cell wall, suggesting that OsCNGC10 was associated with the composition of stem cell wall and negatively regulated lodging resistance in rice. T₂ generation field experiment indicated that compared with the wild type, oscngc10-2 significantly increased plant height, the effective panicle length, panicle number, seed setting rate, 1000-grain weight, and yield per plant. The results of drought stress at seedling stage showed that malondialdehyde (MDA) content accumulated rapidly in OsCNGC10 defective plants under drought stress and insufficient free proline (Pro) was formed, while the free Pro content in OsCNGC10 plants was significantly increased. Moreover, the MDA accumulation rate was relatively slow, which preliminarily indicated that OsCNGC10 positively regulated the drought resistance at seedling stage. The results of this study indicated that OsCNGC10 might have a potential function in lodging resistance and drought resistance in rice, which providing a theoretical basis and new germplasm resources for the breeding lodging resistance and high yield of new rice varieties.

Based on the soil fertility and fertilization level in the Chongqing region, to ensure the stable and high-quality crop yields, we explored the effects of reducing nitrogen and potassium application on sweet potato yield, quality, nutrient utilization, and soil fertility, in order to determine whether there is any space for reducing fertilizer application in sweet potatoes in this area and propose the appropriate reduction application strategy. Field experiments were conducted in two consecutive years from 2021 to 2022 at the base of the Potato Crops Research Institute of Southwest University in Xiema Street, Beibei District, Chongqing. Double factor randomized block experimental design was adopted with three levels of nitrogen and potassium applied in this study. The conventional N application rate was 126.00 kg hm^-2 (A1), the N application rate was reduced by 10% (A2) and 20% (A3), respectively. The conventional application amount of K₂O was 96.00 kg hm^-2 (B1), the application amount of K₂O was reduced by 5% (B2) and 10% (B3), respectively. The results showed that moderate N and K₂O reduction combined application would not significantly reduce the yield of sweet potato, but reducing N by 20% significantly reduced the number of sweet potato per plant, and the yield of A3 significantly reduced by 9.25% compared to A1. Compared to the control, the soluble sugar content of A2 and A3 significantly increased by 0.25% and 0.36%, respectively, while B3 significantly increased by 0.47% compared to B1. However, it was unfavorable to the starch content and soluble protein content of sweet potato. Therefore, compared with local conventional N and K₂O fertilizer application, both reducing N by 10% (A2, 119.70 kg hm^-2) and K₂O by 5% (B2, 86.40 kg hm^-2) did not significantly decrease the yield of Yushu-198 and soil enzyme activity, which could be recommended as the appropriate fertilization recommendation for sweet potato production in this region.

Aiming at the problems such as prominent seasonal drought, large loss of precipitation and runoff, low yield-benefit of sorghum in southwest sloping farmland in China. During 2020-2021, the 7° yellow soil gentle slope cultivated land of previous spring corn was taken as the research object in the southwestern mountains area of Guizhou Province. The effects of three different treatments of traditional open field plain cropping (CK), alternating plastic film strip mulching only on ridge and furrow planting (RFM), and alternating whole maize straw strip mulching only on ridge and furrow planting (RSM) on runoff, water consumption characteristics, water use efficiency, yield and net economic benefits of sorghum were studied under the Transverse Slope Planting Model (TSPM: crop row direction is perpendicular to slope direction). Compared with CK, both RFM and RSM treatments under the TSPM significantly decreased rain-runoff depth during the whole growth period by 27.3% and 42.1% on average, and the water intake coefficient increased by 9.5 and 14.6 percentage points on average, respectively. The water consumption during the growth period of sorghum was significantly increased by the two strip-mulching only on ridges and cross planting in furrows, and the water consumption during the jointing stage to heading stage and the grain-filling stage to maturity stage were significantly (r = 0.51^*) and extremely significantly (r = 0.81^**) positively correlated with the grain yield, respectively. Compared with CK, RFM and RSM significantly increased biomass, kernels per spike and 1000-grain weight at maturity, and grain yield for sorghum was significantly increased by 8.5% and 6.2%, respectively, while water use efficiency was significantly decreased by 12.6% and 21.4%, respectively. Strip-mulching ridge treatments could increase the soil water storage of 0-100 cm soil profile during the whole sorghum growth stage, increase water consumption amount from jointing to heading and from grain-filling to maturity stage. Strip-mulching also improved the growth and development of sorghum plants and the formation of grain yield. Compared with CK, the increase of sorghum straw yield (21.4%) in maturity was significantly higher than that of grain yield (7.3%). Although the increase of straw yield reduced the water use efficiency, it was an important guarantee for grain yield increase. Compared with CK, the average net economic benefit and the output/input for RSM treatment increased by 2962.9 Yuan hm^-2 and 2.3%, respectively, while the average net economic benefit and the output/input for RFM treatment decreased by 1502.6 Yuan hm^-2 and 32.6%, respectively, due to the obvious increase of labor intensity, mechanical and plastic film input. Therefore, RSM treatment can significantly improve effectiveness of precipitation and achieve double increase yield and net economic benefit, which is a feasible model to increase the yield-income of sorghum in yellow soil slope farmland in southwest China.

The objectives of this study were to improve the water use efficiency of spring maize in the valley plains of the eastern Loess Plateau and to identify the most suitable surface mulching measure for spring maize cultivation in this region. Field experiments were conducted from 2021 to 2022 based on a seven-year long-term positioning experiment. Three treatments including no mulching control (CK), plastic film mulching (FM), and straw mulching (SM) were selected. The effects of different mulching measures on moisture content and temperature of soil as well as yield and water use efficiency of spring maize were investigated, and the dynamics of soil moisture, soil temperature, and the water productivity of spring maize at each growth stage during the two-year experimental period were systematically analyzed, so as to provide a scientific management measure of efficient water and fertilizer use in spring maize growing, which is beneficial to the sustainable agricultural development of the region. The results indicated that plastic film mulching had a temperature-raising effect compared with the control, showing an increase of 0.72-2.63℃ in soil temperature in two years. Straw mulching had a cooling effect and the soil temperature was reduced by 0.20-1.51℃ in two years. Compared with the control, the soil moisture content at the early growth stage of spring maize was increased in both FM and SM treatments, and the “alternation of wetting and drying” in soil was induced to promote water absorption, water use efficiency, and eventually crop yield. However, shallow roots were found in the plastic film mulching treatment although the growth of spring maize was promoted at the early stage of growth, which lowered water use efficiency at the later stage of growth and posed a risk of lodging (the lodging percentage reached 72.14% in 2021), and consequently affected yield formation. Compared with the FM treatment, the SM treatment exhibited stronger buffering capability to the fluctuation of soil moisture content as the “alternation of wetting and drying” in soil, coordinated the growth and development of spring maize at different stages. As a result, the water use efficiency was significantly improved by 25.17%-34.71% at the later growth stage, and the risk of lodging was reduced in SM. The mean values of the data in two years showed that, compared to plastic film mulching, straw mulching significantly improved the yield, water use efficiency, and the economic benefits by 8.55%, 10.23%, and by 12.57%, respectively. In summary, straw mulching could serve as the scientific management measure for the efficient and sustainable utilization of water and fertilizer in spring maize plantation in this region.

The optimization of agricultural practices such as nitrogen and straw input may be an effective option for maintaining environmental sustainability. However, previous studies on the effects of nitrogen and straw inputs on wheat growth and N₂O emission reduction were limited. Therefore, the present study was based on the literature published from 2000 to 2022 about wheat yield and N₂O emissions under different nitrogen and straw inputs amendment in the middle and lower reaches of the Yangtze River, a random forest (RF) model of wheat yield and N₂O emission was constructed. And the influence of nitrogen and straw inputs on wheat yield and N₂O emissions was quantified. Based on the developed model, wheat yield and N₂O emission simulations at the experimental site were carried out in combination with scenario settings, and the carbon emission intensity (CEE) and net ecosystem economic benefits (NEEB) were evaluated. The results were as follow: On the regional scale, an RF model was established for the response of wheat yield and N₂O emission to the application of nitrogen fertilizer and straw returning. The verification results were R² of 0.66 and 0.65, and RMSE of 0.70 and 1.11, respectively. Quantifying the importance of independent variables showed that nitrogen application rate and soil organic matter were essential for yield and N₂O models. For nitrogen fertilizer and straw management under different targets, the amount of nitrogen fertilizer required to achieve the highest yield was 208-212 kg hm^-2, the amount of nitrogen fertilizer required to achieve the minimum CEE was 113-130 kg hm^-2, and the amount of nitrogen fertilizer required to achieve the highest NEEB was 202-205 kg hm^-2, of which the highest ecological benefit of 13,669.18 CHY could be obtained by applying 202 kg hm^-2 nitrogen fertilizer under the straw input of 6.75 t hm^-2. Our results indicate that optimizing nitrogen fertilizer and straw inputs has the potential to reduce crop carbon emission intensity and maximize net ecological and environmental benefits.

To ensure national food and edible oil security, it is important to identify the yield gap and yield-limiting factors of rice-rapeseed cropping system at farmer level. In this study, Wuxue city, Hubei province, a typical rice-rapeseed cropping system production area in China was selected for the research. The annual system yield gap was evaluated by a mixed approach of crop modeling and field investigation. Comparisons were conducted among smallholders in terms of soil conditions and management practices by the methods of one-way ANOVA and conditional inference tree. The objective of this study is to identify the crucial yield-limiting factors for smallholders, to explore practical strategies to further increase system yield, and to provide innovative insight into how to adapt specific strategies to close the yield gap based on local conditions. The results showed as follows: (1) The potential yields of rice and rapeseed seasons in Wuxue were 11.79 t hm^-2 and 4.43 t hm^-2, respectively, and the maximum annual system potential energy was 284 GJ hm^-2 based on the equivalent energy of rice and rapeseed. The actual yields for rice and rapeseed seasons were 8.11 t hm^-2 and 1.82 t hm^-2, respectively, and the average annual actual system energy was 165 GJ hm^-2. The average annual relative yield gap (the ratio of yield gap to potential yield) was 42%, and rapeseed (59%) had a greater space for yield increase than rice (31%) within the system. Compared with the average yields of Hubei province and Yangtze River Valley (YRV), the annual potential yield in Wuxue was similar, while the annual actual yield was 13% and 5% lower, respectively, resulting in a relatively large system yield gap in Wuxue. Specifically, approximately 83% and 61% of smallholders in Wuxue had larger relative yield gaps than the average levels in Hubei and the YRV, respectively. (2) Smallholders with relative low system yields presented the following characteristics: sandy-loam soil and low plowing depths, severe weed and pest damage, all fertilizers were applied as basal fertilizer in rice season, low annual fertilization input in rice season and high input in rapeseed season, and high rapeseed mechanical harvesting damage. (3) Most (89%) of smallholders in Wuxue planted the conventional rice Huanghuazhan, which has reached approximately 90% of its potential yield. In addition, rapeseed yield varied among different varieties. In conclusion, the rice-rapeseed system in Wuxue still had a large space for increasing production. The technical measures to reduce the yield gap of the local rice-rapeseed system including: appropriate deep plowing to increase soil production capacity, choosing suitable rapeseed high-yielding varieties in the rapeseed season. For rice season promoting hybrid rice varieties with high potential yield and good quality, increasing planting density, and strengthening weed control at sowing stage in rice season, and emphasizing topdressing in which only basal fertilizer is applied in rice season. Moreover, for the whole seoson fertilizer management it is important for local smallholders to reduce the amount in rapeseed season and increase the amount in rice season.

In double-cropping rice areas in the Yangtze River Basin (YRB), ensuring the yield of late-seeded rapeseed is essential to reduce the winter fallow fields. Additionally, promoting the accumulation of dry matter before winter and improving cold resistance during the overwintering period are effective ways to increase the yield of late-seeded rapeseed. Soaking seeds with exogenous substances is an effective measure to improve the cold resistance during the overwintering period and promote the rapid growth before winter. In this experiment, the early maturing rapeseed variety Huayouza 137 was selected, while soaking-seed treatments of water (CK); 0.01 mmol L^-1, 0.05 mmol L^-1, 0.10 mmol L^-1 betaine (T1-1, T1-2, T1-3); 0.1 mmol L^-1, 0.5 mmol L^-1, 1.0 mmol L^-1 proline (T2-1, T2-2, T2-3); 0.03%, 0.15%, 0.30% hydrogen peroxide (T3-1, T3-2, T3-3); 0.001 mmol L^-1, 0.01 mmol L^-1, 0.05 mmol L^-1 malic acid (T4-1, T4-2, T4-3); 25 mg L^-1, 100 mg L^-1, 300 mg L^-1 nano zinc oxide (T5-1, T5-2, T5-3); 0.5 mmol L^-1, 1.0 mmol L^-1 polyamines (T6-1, T6-2) were conducted between 2021 and 2023 rapeseed growing season. We studied the effects of soaking seeds with different exogenous substances and their levels on the cold resistance in winter and yield of late-seeded rapeseed. The results showed that the different exogenous substances and their levels of soaking seeds affected the germination rate of late-seeded rapeseed, and part of them, such as T3-3, T4-2, and T5-3, significantly increased by 19.2%, 15.3%, and 17.3% versus CK. Soaking seeds with some exogenous substances significantly improved the cold resistance of late-seeded rapeseed in winter. On the one hand, the activities of peroxidase, catalase, and the content of glutathione were improved, and the contents of hydrogen peroxide, active oxygen and MDA reduced; on the other hand, the contents of soluble sugar, proline, malic acid, polyamine, and mannitol were increased; at the same time, the content of membrane cold response protein kinase was increased. The increase of leaf cold resistance was beneficial to the accumulation of leaf biomass and the increase of effective branches and pod number per plant, thus promoting yield. In addition, 9 positive and 3 negative cold resistance indicators were comprehensively evaluated. The results showed that the two-year average yield ranking and the comprehensive evaluation value ranking of cold resistance were basically the same over the two years. While the soaking-seed treatments with the best yield and cold resistance were T5-3, T5-2, T2-3, and T1-2. These results of this study provide theoretical and technical support for the cultivation of late-seeded rapeseed seedlings before winter and the improvement of cold resistance in the YRB, and provide a basis for the stress resistance and stable production of late-seeded rapeseed and the development and utilization of winter fallow fields.

This study aims to investigate the formation characteristics of yield advantage of japonica/indica hybrid rice under field conditions of coastal saline-alkali land. From 2021 to 2022, three types of rice cultivars, including japonica/indica hybrid rice (Yongyou 2640 and Yongyou 4949), conventional japonica rice (Nanjing 9108 and Huaidao 5), and hybrid indica rice (Fengyouxiangzhan and Y Liangyou 372), were grown in two typical fields of medium saline-alkali soil (MS, the average soil conductivity 2.7 dS m^-1) and heavy medium saline-alkali soil (HS, the average soil conductivity 7.2 dS m^-1) selected in coastal saline-alkali land of Jiangsu province to investigate the effects of salinity stress on the yield and formation characteristics of different types of cultivars under field conditions. Compared with MS: (1) The number of panicles, the spikelets per panicle, filled-grain percentage, and 1000-grain weight of three types of rice under HS were significantly lower than MS. The yield of japonica/indica hybrid rice was significantly higher than MS and HS, which was mainly attributed to its more spikelets per panicle. (2) Tiller number of rice population at the main growth stages (jointing, heading, and maturity stages) and the percentage of productive tiller of three types of cultivars decreased significantly HS. The conventional japonica rice and hybrid indica rice had consistently more tiller number of rice population at the main growth stages and percentage of productive tiller than japonica/indica hybrid rice. (3) Dry matter weight at the main growth stages of three types of cultivars were significantly reduced under HS. The japonica/indica hybrid rice had higher dry matter weight at heading and maturity stages, and the crop growth rate from jointing to heading and from heading to maturity than MS and HS. The japonica/indica hybrid rice had higher harvest index than conventional japonica rice and hybrid indica rice under HS. (4) Leaf area index at the main growth stages and leaf area duration from sowing to jointing, from jointing to heading, and from heading to maturity of three types of cultivars were significantly reduced under HS. The japonica/indica hybrid rice had higher leaf area index at maturity stage, and leaf area duration from heading to maturity, while the lower reduction rate of leaf area index from heading to maturity, than MS and HS. (5) The plant height, length and width of upper three leaves, leaf SPAD values, and leaf photosynthetic rate of three types of cultivars were decreased significantly under HS. The leaf length and leaf width, leaf SPAD value, and photosynthetic rate of indica-japonica hybrid rice were higher than MS and HS. The results demonstrated that salinity stress significantly affected rice yield and its formation characteristics under saline-alkali lands. Compared with conventional japonica rice and hybrid indica rice, japonica/indica hybrid rice still had a higher yield advantage under salinity stress, which was mainly due to the more spikelets per panicle. Besides, higher crop growth rate, larger upper three leaf area, and stronger stay-green characteristics after heading were important traits underlying superior yield performance of japonica/indica hybrids under saline-alkali lands.

To study the effects of different precrop straw return and water and N management on rice yield formation, dry matter accumulation and distribution, and N uptake and utilization under diversified cropping patterns. In 2018-2019, hybrid rice F you 498 was used as the experimental material, and a three-factor split plot design was adopted. The main plot was conducted with three planting modes of rape-rice (P_y), wheat-rice (P_x), and cabbage-rice (P_q). In the field, the split area was equipped with two water management methods including conventional flooding irrigation (W₀) and alternating wet and dry irrigation (W₁). The split area was equipped with three N levels including no N treatment (N₀), conventional N application treatment (N₁), and precise N reduction (N₂). The decomposition rate, N release rate, dry matter accumulation, and the distribution of various rice nutrient organs, plant N uptake and utilization of straw returned to the field under different treatments at jointing, heading, and maturity stages, and grain yield were analyzed and measured. The results showed that the average yield of P_y increased by 2.55% and 13.99%, respectively, compared with P_x and P_q, mainly due to its higher effective panicles and 1000-grain weight. P_y promoted the accumulation of dry matter and N in various nutrient organs, which was beneficial to dry matter distribution, to improve the stem sheath N contribution rate and N fertilizer utilization rate, the average total dry matter accumulation and total N accumulation at each stage of P_y increased by 5.25%, 7.48%, and 14.60%, 17.30%, respectively, compared with P_x and P_q. The partial factor productivity of N increased significantly by 24.90% compared with P_q, but the straw decomposition rate and N release rate of P_y were lower. The rice yield of W₁ treatment under the three modes increased by 5.10% (P_y), 1.76% (P_x), and 4.80% (P_q), respectively, compared with W₀ treatment. W₁ treatment promoted straw decomposition and N release, promote dry matter accumulation and N uptake and transport are beneficial to dry matter distribution in P_y and P_x modes, thereby improving N fertilizer utilization efficiency. Under the same straw return and water management, N₂ treatment promoted straw decomposition and N release, which was beneficial to dry matter distribution and N transport, and increased N accumulation in stem sheaths and leaves at heading and maturity stages, thus improving N fertilizer utilization efficiency. However, the yields and dry matter accumulations in N₂ treatment decreased slightly compared with those in the N₁ treatment, but there was significant difference between them. Comprehensive analysis showed that under the rape-rice planting model, returning rapeseed straw to the field combined with alternating dry and wet irrigation and precise N reduction (120 kg hm^-2) was beneficial to dry matter accumulation and distribution, N uptake and transport, and thus improving the agronomic efficiency of N, and partial factor productivity of N, and can save 20% of N fertilizer input to achieve stable and efficient rice production.

Vitamin E (Ve) is a natural antioxidant in soybean oil and an important index to evaluate the nutritional value of soybean oil. In this study, α-, γ-, and δ- contents of seed were determined from a natural soybean population containing 264 germplasm resources in 2021 and 2022, and genome-wide association study (GWAS) was conducted. A total of 199 SNPs significantly associated with soybean Ve content were detected in this study, among which 9 SNPs that could be repeatedly detected in two different environments or two traits, which located on chromosomes 3, 7, 11, 12, 13, 15, 17, and 18, respectively. Among them, the significant association signal on chromosome 7 was a major effect site controlling α-tocopherol content, which can be detected in two environments, with the explanation rate of phenotypic variation 9.83%. By screening the candidate genes of this site, Glyma.07G054000 encoding myb transcription factor was obtained, which may be the effect gene of this site. In addition, two genes encoding γ-tocopherol methyltransferase Glyma.12G014200 and Glyma.12G014300 obtained on chromosome 12, may be important genes affecting Ve content. The results of this study are helpful to analyze the genetic basis and regulatory mechanism of Ve content in soybean seed, and lay a foundation for genetic improvement of soybean quality.

The primary variety of fresh maize known as waxy maize undergoes a transformation with the introduction of the opaque2 (o2) mutant gene, resulting in an increased lysine content, thus improving the grain's nutritional composition. Yet, the o2 mutation brings about desirable agronomic traits such as wrinkle formation and a decrease in starch content, which restrict its use in breeding applications. To explore the high performing waxy maize o2 receptors, we capitalized on the use of o2 near-isogenic line (o2-NIL), specifically the plump and round grain type Nuo 2/wx1wx1o2o2 and its wrinkled counterpart, Huangnuo2/wx1wx1o2o2. Measurements of 100-grain weight and grain composition at the fresh ear and mature stages showed that there was difference in starch and soluble sugar content, which might be the primary cause of kernel phenotype variation between the two waxy maize o2-NILs. Genetic analysis of starch synthesis in the two o2-NILs was performed using qRT-PCR technique revealed that six gene-regulated trends fluctuated between 10 and 24 days after pollination, among which Sh1, Sh2, SSIIIa, and SBEIIb genes were significant differences. Endosperm transcriptomes indicated that 24 genes encoding trehalose and glycosyl hydrolases and 48 genes involved in endosperm modification exhibited distinct changes between the two o2-NILs. There was no detectable alteration in the 100-grain weight or the starch content of Nuo 2/wx1wx1o2o2, which may well be tied to the early high-level expression of the primary starch synthesis gene, leaving later stages unchanged compared with the control. Furthermore, the shifts in the expression of sugar metabolism genes was beneficial to starch synthesis, which may be an important reason why starch content and 100-kernel weight of Nuo 2/wx1wx1o2o2 were unaffected by the o2 mutation, and grain traits were significantly better than the superior grain traits compared with Huangnuo 2/wx1wx1o2o2. These results may be directly related to the differential expression of multiple endosperm modifying genes. The results of this study can provide important reference for the future utilization of o2 mutants in maize breeding.

Salt tolerance identification is the premise of screening germplasm and breeding salt-tolerant wheat varieties. There are many methods for testing salt tolerance of wheat indoor, involving different growth stages and tissues or organs. In order to evaluate the applicability of these methods in production, we selected five salt-tolerant varieties and five salt-sensitive varieties from the Northern Winter Wheat Production Area of China to compare seven identification methods (involving 27 parameters) for the responses to salt stress of wheat at germination and seedling stages. The results showed that the relative salt-injury rate for germination of grains could not distinguish the tolerant- and sensitive-varieties, while the salt-injury index of leaf, the Na⁺ and K⁺ fluxes of root, and the relative salt-injury rates for root tip number, root diameter as well as leaf K⁺ content of seedlings were significantly different between the tolerant- and sensitive-varieties. Based on the results of regressive analysis and operability, the salt-injury index of leaf was considered to be an appropriate method for identifying salt tolerance that with high applicability in the Northern Winter Wheat Production Area, which can be used for germplasm screening or variety breeding by integrating the relative salt-injury rate for root tip number or leaf K⁺ content, and the Na⁺ or K⁺ flux of root. This study analyzed and evaluated

the salt tolerance identification methods from the aspect of application, and provide reference information for salt tolerance breeding in wheat.

In this study, 500 proso millet resources in Northeast Spring Sowing Region were used as the experimental materials, 169 SSR markers, UPGMA clustering, and stratified sampling were used to construct core germplasm, and ID Analysis 4.0 software was used to construct molecular identity card. The genetic diversity of the core collection was evaluated by genetic diversity metrics such as allele number (N_a), and the core collection was analyzed by PCOA. The results showed that 169 pairs of SSR primers were screened, and 30 pairs of SSR primers were found to have good polymorphism. The core collection of proso millet constructed by 30 pairs of SSR primers contained 190 materials, accounting for 38% of all germplasm. Ninety-one alleles were detected in all germplasm and core collection, and 100% alleles were retained. The number of effective alleles was 2.2977-2.9975 and 2.2872-3.0173, with an average of 2.8198 and 2.8297, respectively. The Shannon diversity index was 0.9532-1.0990 and 0.9535-1.1162, with an average of 1.0645 and 1.0667. The observed heterozygosity was 0.3434-0.8037 and 0.3162-0.7849, with an average of 0.5399 and 0.5359. The expected heterozygosity was 0.5654-0.6672 and 0.5645-0.6707, with an average of 0.6448 and 0.6473. Nei’s gene diversity index was 0.5648-0.6664 and 0.5628-0.6686, with an average of 0.6441 and 0.6452. The polymorphism information content was 0.6657-0.8356 and 0.6493-0.8340, with an average of 0.7974 and 0.7944. The results of t-test showed that there was no significant difference in the related indexes of molecular markers between all germplasm and core germplasm, and PCOA analysis showed that the core germplasm and all germplasm had similar genetic diversity and population structure. At the same time, 8 SSR markers (RYW5, RYW8, RYW16, RYW28, RYW40, RYW53, RYW62, and RYW67) were found to distinguish 190 core germplasms, and the molecular identity card of the core germplasms of Northeast proso millet was constructed, which providing a scientific basis for the efficient utilization and rapid traceability of proso millet germplasm.

Transgenic engineered breeding is an effective way of cotton germplasm innovations. In order to expand the renewable genotypes of upland cotton and to enrich cotton transgenic receptors, we constructed an F₉ recombinant inbred population (YE) by the single-seed descent method using the high-yielding broad leaf cotton variety Emian 22 (E22) from Hubei province as the male parent and the high regeneration-capable okra leaf variety Yuzao 1 (YZ1) as the female parent. We compared the callus induction rate (CIF), callus secondary fecundity (CSC), embryo rate of callus (CRE), and callus embryo time (CET) of 164 recombinant inbred lines using two different hormone combinations of IBA+KT (IK) and 2,4-D+KT (DK), respectively, which were mature tissue culture systems in cotton. A total of 12 regenerable broad leaf lines were obtained and evaluated for the genetic transformation efficiency using the current mature genetic transformation system in cotton; meanwhile, agronomic traits of these lines were investigated. Finally, a family line YE3, with a genetic transformation efficiency of 82.9% and better agronomic traits, was obtained. This study develops a new genotype of upland cotton, which will facilitate the genetic transformation and gene function research of cotton.

During the production of Brassica napus, the yield and quality of the crop are seriously affected by a large number of accompanying weeds. Herbicide control options are rapidly diminishing due to the recent increase in the number of herbicide-resistant weeds in fields, which affects the sustainable development of agriculture in the future. Plants can take up phosphite (Phi) via orthophosphate (Pi) transporters, but the Phi cannot be metabolized and used as a phosphorus fertilizer for crops, resulting in plant growth inhibition. Previously, a ptxD gene isolated from Ralstonia sp. 4506, and the mutant protein ptxD_Q at position 139, which had tyrosine mutation to glutamine (Y139Q), significantly improved the conversion activity of Phi to Pi. To evaluate the efficacy of ptxD_Q/Phi-based weed control system in Brassica napus, we generated transgenic B. napus plants with a codon-optimized ptxD (Y139Q, ptxD_Q) gene. Ectopic expression of ptxD_Q confered the ability to convert Phi to Pi, resulting in improving plant growth in the presence of Phi. Pi-starvation-induced genes (e.g. PT21 and PT24) were suppressed in the ptxD_Q transgenic lines by supplying Phi, indicating that ptxD_Q can transform Phi into Pi in rapeseed. In addition, ptxD_Q transgenic Brassica napus had a greater competitive growth advantage over wild-type Brassica napus and monocotyledonous weeds (Setaria glauca). In conclusion, the ptxD_Q/Phi system provided an effective alternative for suppressing the weed growth while providing adequate Pi nutrition to the crops, which in turn improved the sustainability of agriculture.

Seed germination stage is sensitive to salt. The determination of cotton seed germination under different salt concentration stress is one of the important bases for screening cotton salt-tolerant germplasm. In this study, 629 cotton germplasm resources were treated with 0 mmol L^-1 and 150 mmol L^-1 NaCl, and the salt tolerance coefficients of 6 traits such as fresh weight and germination potential were analyzed. The results showed that there were significant differences in each trait under salt stress compared with the control. Principal component analysis and membership function analysis were used to comprehensively evaluate the salt tolerance of cotton germplasm. Cluster analysis was carried out on the comprehensive evaluation value (D-value), and 629 germplasm resources were divided into 5 categories according to the D-value: 188 medium salt-tolerant materials, 376 salt-tolerant materials, 36 high salt-tolerant materials, 28 salt-sensitive materials, 1 high salt-sensitive material. A prediction model for salt tolerance evaluation of cotton at germination stage was established by stepwise regression analysis: D = 0.277RFW + 0.29RGP + 0.189RPL + 0.387RGR-0.32 (R² =0.992). Four indexes of fresh weight, hypocotyl length, germination potential, and germination rate were selected as the indexes of salt tolerance identification in cotton germination stage. In this study, a set of accurate and efficient salt tolerance identification system was established, and 4 high salt-tolerant materials and 1 high salt-sensitive material were screened, which providing the reference for the study of salt tolerance mechanism and the cultivation of new salt tolerant varieties in cotton.

Rapeseed (Brassica napus L.) is the main source of edible vegetable oil in China, and increasing seed oil content is the most effective way to increase the supply of rapeseed oil. In this study, 43 genes related to lipid synthesis were selected by analyzing the seed transcriptome data of 4 rapeseed inbred lines 25, 35, and 45 days after pollination. Among them, 33 genes were continuously up-expressed and 10 genes were continuously down-expressed from 25 to 45 days of seed development. The main genes included BnLEC1, BnABI5, BnOLEO4, and BnOBAP1a. At the same time, combined with the resequencing data of 50 semi-winter Brassica napus, 3 SNPs and 9 SNPs significantly related to oil content were detected to BnOBAP1a-A10 and BnABI5-A05, respectively, and the oil content of BnOBAP1A-A10_Hap1 was significantly higher than Hap2. The oil content of BnABI5-A05_Hap1 was significantly higher than Hap3. In addition, WGCNA was used to construct gene networks, and we found that BnOBAP1a and BnABI5 were indirectly connected through three transcription factors LEC1, HMGB3, and HTA11, which together formed a molecular network involved in the potential regulation of seed oil accumulation. The results of this study provide valuable insights for the development of haplotype functional markers, aiming to further enhance oil content in B. napus.

The decrease of plant height in maize is usually caused by the decrease in the number of internodes, the shortening of internodes or the combination of both. However, in this study, the mutant leafy dwarf1 (lyd1) found in the progeny of gene editing, exhibited more leaves and shorter stature. Quantitative measurements indicated the plant height of mutant lyd1 was only 93.10 cm, the plant height of wild-type KN5585 was 159.95 cm. The plant height was significantly reduced by 41.79% in mutant lyd1 compared with the wild type KN5585. The wild type KN5585 produced an average of 17.8 leaves at maturity stage, whereas mutants lyd1 produced 27.8 leaves. The number of leaves were significantly increased by 56.18% in mutant lyd1 compared with the wild type. Genetic analysis showed that the mutation phenotype of lyd1 was controlled by a pair of recessive nuclear genes. We applied a map-based cloning strategy to identify the gene responsible for the lyd1 phenotype. The gene was located between Indel10 and Indel11 on maize chromosome 3, and the physical distance was 0.74 Mb. Gene sequencing analysis of 13 genes (excluding pseudogenes) within the interval revealed that one base A was substituted in the fourth exon of ZmTE1, and there was no significant difference in other genes. ZmTE1 encoded an RNA-binding protein. The amino acid substitution was in the third RNA binding domain (RRM3), resulting in the conversion of aspartic acid to valine. The mutation sites of the mutant lyd1 were different from te1-mum1, te1-mum2, te1-mum3, and zm66 in previously reported. The discovery of lyd1 provides valuable materials for further analysis of the genetic mechanism of the balance between leaves and internodes development in maize.

Variety genuineness is an important indicator for seed quality monitoring. In order to establish accurate, reliable, fast, simple, high-throughput, and low-cost maize variety genuineness identification technology, we evaluated and determined a set of high discriminative power core SNP loci set including 96 SNPs based on SNP fingerprint data of 5816 maize hybrids and 3274 inbred lines using the genetic algorithm and variety recognition rate. All 96 SNPs were located in the intra-gene region, generally distributed evenly on 10 pairs of chromosomes. The evaluation results using the above hybrid and inbred line data showed that 96 SNPs set had high polymorphism and variety discrimination power. The average values of PIC, MAF, and DP were 0.36, 0.40, 0.60, and 0.36, 0.39, 0.48 for hybrids and inbred lines, respectively. The variety discrimination power for hybrids and inbred lines reached 99.14% and 99.24%, respectively. Pairwise comparison between varieties showed that 99.99% of the comparisons had at least three differential loci. About 96.74% of hybrids and 95.67% of inbred lines mostly had the 30-65 and 30-60 differential loci between varieties, respectively. Compared with the 40 SSRs genotype dataset using 221 hybrids, the 96-SNPs set had high consistency in the identification results of the two marker sets. In summary, the optimal core SNPs set reported in this study had the advantage of the minimum number of loci, the highest discrimination power, the strongest differentiation platforms, and the automatic genotyping. It is expected that the extensive application of this core SNP loci set will be widely used in maize variety genuineness monitor and seed quality control for maintaining seed market order, so as to defend the breeders’ rights and protecting interests of farmers.

Male sterile material is the key to hybrid rice breeding. In this study, a male sterile mutant tpa1 was screened by ethyl methane sulfonate (EMS) mutagenesis of excellent indica cultivar Xinong 1B. There was no difference between tpa1 and wild type at vegetative growth stage. At reproductive stage, male gametes were sterile and female gametes developed normally. Phenotypic observation showed that the pollen of tpa1 was completely broken and disappeared, the stratum corneum of the outer wall of the anther was abnormal, the Ubisch body of the inner wall of the anther was abnormal, the callose synthesis was abnormal, the tapetum apoptosis was abnormal, and the outer wall of the pollen was missing bacula layer. Genetic analysis showed that the mutant trait was controlled by a pair of recessive nuclear genes. A genetic population was constructed using the tpa1 mutant and Jinhui 10. Finally, TPA1 gene was located between the markers N9 and N11 on chromosome 4, with a physical distance of 74 kb. There were 15 predicted genes in this interval. Resequencing identified that only a single base substitution occurred in the exon of LOC_Os04g53380, leading to an early termination of translation. Subsequent sequencing of the wild-type and mutant tpa1 confirmed this mutation, thus identified the gene as a candidate gene for TPA1, indicating that TPA1 was a new male sterile gene. This study will lay a foundation for the functional study of TPA1 gene.

Root-stem transition zone (RSTZ) connects roots and stems, and its morphology modifies the structure of aerial part and lodging resistance potential in soybean. In this study, a soybean mutant M_rstz, appearing with curved or rotated RSTZ, was obtained by EMS mutagenesis. Its morphological characteristics were stably inherited and could provide specific sources for exploring the development patterns of soybean stems. Therefore, this mutant was crossed with Zhonghuang 13 to construct a recombinant inbred line population. By comparing the anatomical structure of vertical RSTZ and curved RSTZ, the wider vascular cambium, more secondary xylem cell layers and irregular cell shape were identified in curved lines, indicating that vascular cambium differentiation may be one of the important factors leading to the difference of RSTZ morphology. Subsequently, the chemical compositions of lines with vertical RSTZ or curved RSTZ were determined, respectively. It was found that the higher lignin and crude fiber content in the RSTZ, the more difficult to bend. The RSTZ with curved or vertical lines were further selected for BSA-seq. SNP-index and InDel-index methods were employed to mine a significant association region, Chr. 19: 43,030,943-45,849,854 containing 319 genes, which may regulate RSTZ morphology. Combined bioinformatics analysis, gene annotation information and expression abundance analysis, seven candidate genes (Glyma.19G170200, Glyma.19G201500, Glyma.19G187800, Glyma.19G178200, Glyma.19G197000, Glyma.19G179100, Glyma.19G196900) were screened. Among them, Glyma.19G187800, Glyma.19G178200, and Glyma.19G196900 potentially affected RSTZ morphogenesis in soybean domestication. This study not only provides germplasm resources for the understanding of soybean RSTZ tissue formation and its genetic basis, but also provides new insights for further exploration of genes regulating soybean stalk development.

In order to explore the mechanism of exogenous salicylic acid in improving the resistance of wheat stripe rust, using, the untreated wheat seedlings (control), stripe rust wheat seedlings (SR), and salicylic acid treated stripe rust wheat seedlings (SA-SR) as the experimental materials were investigated using Zhoumai 18. After 15 days of treatment, the wheat seedlings were identified for disease resistance, amino acid detection, transcriptome sequencing, and fluorescence quantification. The results indicated that the exogenous salicylic acid could significantly reduce the pathogenicity of stripe rust in wheat seedlings. The content of amino acids in leaves in the SR group was generally reduced, while there was no significant difference between the SA-SR group and the control group pretreated with salicylic acid, indicating that the content of amino acids in leaves was significantly reduced due to wheat stripe rust. GO enrichment indicated that the differentially expressed genes of SR and SA-SR groups were enriched in biological processes related to photosynthesis involving cell components such as chloroplasts and thylakoids. KEGG pathway enrichment showed that both SR and SA-SR subgroups were significantly enriched in the MAPK signaling pathway and the biosynthesis of secondary metabolites played an important role in plant disease resistance or stress resistance.

Aiming at the problems of high water and fertilizer inputs and low utilization efficiency for maize production in the Oasis irrigation areas, the effects of different irrigation levels and equal nitrogen application ratios of organic-inorganic fertilizer on photosynthesis physiology, grain yield and quality of maize were investigated to obtain the optimal irrigation levels and nitrogen (N) application ratios of organic-inorganic fertilizer. A filed experiment was conducted with the two-factor split-plot, two irrigation levels (conventional irrigation and 20% reduced irrigation) were used in the main plot and five organic and inorganic nitrogen fertilizer ratios (all inorganic N fertilizer, 75% inorganic N fertilizer and 25% organic fertilizer, 50% inorganic N fertilizer and 50% organic fertilizer, 25% inorganic N fertilizer and 75% organic fertilizer, and all organic fertilizer) were used in the split-plot in order to investigate the response of maize photosynthetic physiology, grain yield, and quality to different water and nitrogen fertilizer management patterns. Compared with the conventional irrigation (I2), 20% reduction irrigation (I1) reduced maize leaf area index (LAI), photosynthetic potential (LAD), net photosynthetic rate (P_n), transpiration rate (T_r), and stomatal conductance (G_s), and increased intercellular CO₂ concentration (C_i), grain protein content, and grain threonine content; organic and inorganic fertilizers have a significant effect on maize photosynthetic physiological indicators, grain yield and quality, with the increase in the proportion of organic fertilizers, the effect of organic and inorganic fertilizers on maize will gradually change from a positive effect to a negative effect; compared with traditional irrigation combined with the full application of inorganic nitrogen fertilizer (I2F1), 20% reduction of irrigation combined with 75% inorganic nitrogen fertilizer and 25% organic fertilizer (I1F2) increased the maize mean leaf area index (MLAI) by 6.9%-7.1%, and there was no significant change in total photosynthetic potential (TLAD), and the LAI of I1F2 was increased by 5.0%-11.4% from silking to doughing in maize, and LAD was increased by 7.5%-9.1% from silking to doughing. I1F2 increased chlorophyll content (SPAD), P_n, T_r, and G_s, and decreased C_i in maize from tasseling to doughing compared with I2F1. Compared with I2F1, I1F2 increased grain yield by 12.0%-12.5% in maize, increased grain protein content by 6.9%-18.9%, and Phe, Lys, Thr, Trp, Leu, Ile, and Val contents of grain in maize were increased by 29.6%-43.3%, 77.7%-93.3%, 49.7%-51.5%, 18.4%-28.6%, 39.5%-46.0%, 57.4%-78.1%, and 35.1%-41.3%, respectively. Other treatments also had some effects on maize photosynthetic physiology, seed yield and quality indexes, but the combined two-year results showed that the effects of I1F2 were more significant. Therefore, the 20% reduction in irrigation (3240 m³ hm^-2) combined with 75% inorganic chemical N fertilizer (270 kg hm^-2) and 25% organic fertilizer (90 kg hm^-2) treatment was an appropriate water and N management model to achieve high yield and quality of maize production in the northwestern irrigation areas.

The objective of this study is to investigate the effect of organic fertilizer substitution of some chemical fertilizers on ear yield, quality, and nitrogen utilization of fresh waxy maize, and to explore the optimum organic fertilizer substitution ratio for chemical fertilizer in waxy maize production, which can provide the theoretical basis for the high-quality cultivation of fresh waxy maize in Hebei Plain. The field trials were conducted in 2020 and 2021 using the waxy maize variety Sidanuo 41 as the experimental material. A randomized zonal experimental design was used to set up 6 treatments: no nitrogen application (T1), quantitative fertilizer nitrogen (T2), organic fertilizer substituting 20% chemical fertilizer nitrogen (T3), organic fertilizer substituting 40% chemical fertilizer nitrogen (T4), organic fertilizer substituting 60% chemical fertilizer nitrogen (T5), and organic fertilizer substituting 100% chemical fertilizer nitrogen (T6). The results showed that substituting of T3, T4, T5 treatments with commercial organic fertilizer increased fresh ears yield of waxy maize, increased by 3.08%, 13.61%, and 3.20%, respectively. Compared with T2 treatment, nitrogen use efficiency treatment with T3-T6 were decreased, the partial productivity and agronomic efficiency of nitrogen fertilizer of T3-T5 treatments were significantly increased. The appearance and tasting quality scores of waxy maize under the substituting of commercial organic fertilizer were higher than T2 treatment, and the total score of T4 treatment was the highest, mainly because the substituting some chemical fertilizer by organic fertilizer increased the total starch and pullulan content of grain, reduced the content of grain protein and soluble sugar, and improved grain texture characteristics, increased grain hardness, elasticity and chewiness, and decreased cohesion. In conclusion, under the condition of a total nitrogen application rate of 180 kg hm^-2, the substituting 40% chemical fertilizer nitrogen (T4) with organic fertilizer can improve the yield and quality of fresh ears of waxy maize.

Nitrogen application can increase the availability of nitrogen in the soil, thereby improving plant photosynthesis and promoting the absorption of nitrogen and the accumulation of dry matter, ultimately leading to an increase in crop yield. However, it is unclear whether the nitrogen application rate should be adjusted under long-term high nitrogen straw returning conditions. To investigate the effects of nitrogen application rate on cotton photosynthesis rate, dry matter and nutrient accumulation and distribution, yield, nitrogen utilization, and soil nitrogen changes under long-term straw return conditions, we set up seven nitrogen application rates of pure nitrogen 0 (N0), 150 (N150), 180 (N180), 210 (N210), 240 (N240), 270 (N270), and 300 (N300) kg hm^-2. Compared with the commonly used nitrogen application rate (N300) in field agriculture, from 2020 to 2021, a 30% reduction in nitrogen (N210) achieved higher yields, 1853.62 kg hm^-2 and 1872.43 kg hm^-2 respectively, while a 40% reduction in nitrogen (N180) only maintained a high yield of 1743.68 kg hm^-2 in the first year. In 2021, the net photosynthetic rate, dry matter and nutrient accumulation of N210 were higher than that of N180, and there was no significant difference between them in the dry matter and nutrient partition coefficient of reproductive organs and nitrogen fertilizer use efficiency, but the apparent nitrogen surplus of N180 soil was significantly reduced by 39.15%. In summary, under long-term stubble returning conditions, applying 210 kg hm^-2 of nitrogen is more suitable for achieving the goal of reducing weight and promoting yield in the northwest cotton region of Shandong.

The use of hyperspectral remote sensing technology to monitor crop water status and grain yield is important for regulating crop growth, optimizing water management and improving yield formation. Zhenghong 505 was selected as the maize variety in this study, to analyze the quantitative relationship between canopy water content (CWC) and grain yield of maize at jointing stage (V6), tasseling stage (VT), and filling stage (R2), four drought stress treatments (well-watered, mild, intermediate and severe drought) were conducted in the experimental fields of Ya’an and Renshou in Sichuan Province from 2018 to 2019. The spectral reflectance data were processed using vegetation indices and continuous wavelet transform, and a linear regression method was used to construct a quantitative CWC inversion model to explore the effectiveness of CWC as a bridge to establish a spectral inversion model for maize grain yield estimation. The results showed that the CWC estimation models using wavelet features was better than that of vegetation indices, and the linear regression models constructed with wavelet features gaus3_770,64, rbio3.3_1635,2 and rbio3.3_838,2 at the V6, VT, and R2 stages had high test accuracy with the R² of 0.770, 0.291, and 0.233, respectively. The linear regression models established between CWC and maize grain yield all reached highly significant levels (P < 0.01), with R² of 0.596, 0.366 and 0.439 at the V6, VT, and R2 stages, respectively. The yield prediction model based on the basis of spectral reflectance was the best validated with the wavelet feature gaus3_770,64 (R² = 0.577, RMSE = 1.625 t hm^-2) at V6 stage, which can be used as the best period for predicting maize grain yield. Therefore, the “spectral reflectance-canopy water content-yield” modeling method proposed in this study can achieve an accurate estimation of maize grain yield and provide a theoretical basis for future large-scale monitoring of maize productivity.

The Yangtze River basin is the main producing area of rapeseeds in China, which is wet and rainy all the year round, and the rapeseed-rice rotation system is implemented in the producing area, resulting in frequent waterlogging. To explore the effects of waterlogging at seedling stage on phenotypic traits, physiological characteristics, photosynthesis, relative gene transcriptional levels, and the regulation of exogenous hormone inhibitors on rapeseed damage under waterlogging, a pot experiment was conducted, and the strong waterlogging tolerant line YZ12, medium waterlogging tolerant line YZ45, and weak waterlogging tolerant line YZ59 were used as the experimental materials. The results indicated that flooding stress severely inhibited the growth of rapeseed, and root activity could be used as an indicator to measure the impact of flooding stress on rapeseed growth. The observation of root cell ultrastructure showed that flooding stress led to plasmolysis and organelle fragmentation of rape root cells. The organelle of strong and medium waterlogging resistant rape was less damaged, and it could maintain a more normal cell morphology under flooding stress. The relative transcriptional levels of cytoskeletal genes Bnamicrotubule1.A3, Bnatubulin-α2.C3, Bnatubulin-β7.C6, and Bnalamin-like.A2 in rape roots were significantly decreased under flooding stress, which were 0.2-0.5 times that of the control (CK) samples. The relative expressional levels of BnaPDH.C9, BnaLDH.A1, and BnaADH.A7 associated to anaerobic respiration were significantly increased, which was 3-6 times higher than that of CK, and higher expression levels were observed in medium and strong waterlogging tolerant rapeseed seedlings than in weak waterlogging tolerant line YZ59. During waterlogging, the activities of POD and SOD increased first and then decreased, while the activity of CAT and the content of MDA increased. Among them, the enzyme activities of YZ12 line such as POD, SOD, CAT were relatively high, and the increase of MDA was small. The photosynthetic efficiency and chlorophyll content of rapeseed leaves were seriously affected by flooding stress. The chlorophyll content, photosynthetic rate, stomatal conductance and transpiration rate of rapeseed decreased significantly, and the intercellular CO₂ concentration increased significantly, and the change range of the weak waterlogging tolerant line YZ59 was larger than that of the other two lines. Under flooding stress, ET and ABA contents of rapeseed increased significantly. Among the three lines, YZ12 had higher ET content, while YZ59 had higher ABA content. The relative transcriptional levels of ET related genes BnaACO1.C8, BnaERF73.C6 were significantly up-regulated in the strong waterlogging tolerant line YZ12, while the relative transcriptional level of ABA-related gene BnaZEP.A7 was up-regulated in the weak waterlogging tolerant line YZ59. Exogenous application of hormone inhibitors could improve the damage of flooding stress to rapeseed, but the effects of different exogenous hormone inhibitors varied significantly. In conclusion, there were differences in physiological metabolism, photosynthesis, hormone, and gene transcriptional levels in response to flooding stress at seedling stage in B. napus with different waterlogging tolerance. B. napus responsed to flooding stress by regulating the relative transcription levels of genes related to cytoskeleton, anaerobic respiration, hormone metabolism, causing changes in antioxidant enzyme activity, hormone levels, photosynthetic efficiency, root ultrastructure and root vitality.

Climate change affects species growth areas by altering the suitability of their habitats. As a rare and endangered medical plant in China, the evaluation of the suitable distribution area and the impact of climate change on the suitability of Gastrodia elata can provide important information for the production layout of Gastrodia elata. In this study, the MaxEnt model was used to simulate the spatial distribution and changes of the suitability and suitable area for Gastrodia elata cultivation from 1961 to 2020, based on geographic distribution and environmental data. Results showed that the main environmental factors affecting the distribution of Gastrodia elata were solar radiation from May to July, precipitation in October and November, the minimum temperature in the coldest month, and vegetation type. The high suitable areas for Gastrodia elata cultivation in China were mainly distributed in the southwestern region around the Sichuan Basin. 1961 to 2020, the suitability for Gastrodia elata cultivation had shown a fluctuating increasing trend, with the area of improved suitability accounting for 9.10% of the total land area of China, mainly concentrated in Southwest China, the parts of central and eastern China, and Shaanxi province. The overall decrease in solar radiation from May to July over the past 60 years was the main reason for the increased suitability of asparagus cultivation. This study provided a scientific basis for the production and artificial cultivation site selection of Gastrodia elata in China, which provided reference significance for formulating strategies to respond to future climate change.

The objective of this study is to investigate the effect of elevated atmospheric CO₂ concentration on the canopy spectral characteristics of winter wheat during the whole growth period and to establish quantitative relationships between above-ground biomass (AGB) and spectral parameters based on the screened sensitive bands. For this purpose, during the winter wheat growing season of 2021-2022, two treatment levels of atmospheric CO₂ concentration (ACO₂, (420±20) μL L^-1) and elevated CO₂ concentration (ECO₂, (550±20) μL L^-1) were set based on the Free Atmospheric CO₂ Enrichment System (Mini-FACE), and the changes of spectral features were analyzed under elevated CO₂ concentration. AGB sensitive bands were screened and the estimation models of AGB were constructed based on the successive projections algorithm (SPA), stepwise multiple linear regression (SMLR), and partial least squares regression (PLSR). The results showed that elevated CO₂ concentration significantly increased AGB in winter wheat at jointing and anthesis stages. The red-edge reflectance, near red edge reflectance, and red-edge area increased at jointing stage and decreased at anthesis and maturity stages. The positions of the blue-edge, yellow-edge, and red-edge were shifted at different growth stages. The sensitive spectral bands of AGB are mainly distributed in the red-edge and near red-edge bands, and the elevated CO₂ concentration narrows the range of the sensitive bands of AGB, but does not affect the estimation of AGB. The SMLR and PLSR models of AGB both achieved high estimation accuracy (R² > 0.8), where the characteristic parameters such as R₇₉₉', D_y, SD_y, and PRI in the SMLR model were significantly correlated with AGB, with an R² of 0.866. The PLSR model (R² > 0.9) outperformed the SMLR model in terms of estimation accuracy and stability. This study can provide the theoretical basis and technical methods for the remote sensing monitoring of winter wheat growth and development under elevated CO₂ concentration in the future.

In order to clarify the influence of different sowing width on wheat grain yield and its physiological causes, in the 2019-2020 and 2020-2021 winter wheat growing seasons, two sowing treatments were set under field test conditions at Shijiawangzi Wheat Test Station, Xiaomeng Town, Yanzhou District, Jining City, Shandong Province. Treatment 1 was 8 cm (B1); Treatment 2 is broadcast at 3 cm (B2). The effects of different sowing plots on photosynthetic characteristics, canopy light interception characteristics, dry matter accumulation and transport, and grain yield of wheat were studied. The results showed that the leaf area index and photosynthetically active radiation interception rate of B1 treatment were significantly higher than those of B2 treatment, and the photosynthetically active radiation transmittance of B1 treatment was significantly lower than that of B2 treatment. The relative chlorophyll content, net photosynthetic rate, transpiration rate and stomatal conductance of flag leaves under B1 treatment were significantly higher than B2 treatment, and the intercellular carbon dioxide concentration was significantly lower than B2 treatment. Dry matter accumulation at anthesis and maturity, dry matter distribution in seeds after anthesis and dry matter accumulation at maturity were significantly higher under B1 treatment than B2 treatment. The number of grains per spike and 1000-grain weight of B1 treatment were significantly higher than those of B2 treatment. Compared with B2 treatment, the two-year average grain yield and light energy utilization rate of B1 treatment increased by 6.12% and 7.71%, respectively. In summary, B1 treatment with a sowing width of 8 cm can shape a reasonable canopy structure, improve the photosynthetic performance of leaves after anthesis, and facilitate the production of photosynthetic substances of plants after anthesis, thus obtaining the highest grain yield and light energy utilization rate, which is the optimal treatment under the conditions of this experiment. This research provides a theoretical basis for wide-sowing technology of wheat with water-saving, high-yield and high-efficiency.