To establish a molecular identification system and DNA fingerprint database for hulless barley (Hordeum vulgare L. var. nudum Hook. f.) varieties in China, this study aimed to screen a set of SSR core primers suitable for national variety identification standards, thereby providing technical support for variety authentication, management, and new variety protection. Based on previously reported SSR markers of hulless barley, PCR amplification, marker screening, and validation were performed across diverse varieties, followed by analyses of genetic diversity and discrimination efficiency. Using 155 hulless barley accessions, 200 SSR primer pairs were subjected to polymorphism screening. Twenty-one core primers were selected based on criteria including clear and easily interpretable peak patterns, high polymorphism (mean PIC=0.68), amplification stability, and even chromosomal distribution. Reference varieties (e.g., Yunqing 4, Diqing 4, and Kunlun 8) were employed to validate the stability and reliability of these primers. The constructed DNA fingerprint database for 155 accessions detected 137 alleles, ranging from 2 to 10 per locus (mean=6.52). The polymorphism information content (PIC) values varied between 0.39 and 0.85 (mean=0.68), with 95.24% of loci classified as highly polymorphic (PIC>0.5). These 21 primers achieved a discrimination efficiency of 99.991%, distinguishing 153 out of 155 accessions. Cluster analysis, population structure analysis, and principal component analysis classified the 154 accessions into three distinct groups, revealing rich genetic diversity and simple genetic backgrounds in 45.81% of the accessions. The SSR-based identification system developed in this study demonstrated high accuracy and practical applicability, enabling authenticity verification, auxiliary screening of approximate varieties in DUS testing, and intellectual property protection. Furthermore, the DNA fingerprint database and genetic diversity analysis provide valuable molecular-level insights for future hulless barley breeding programs.

To elucidate the genetic variation patterns of agronomic traits in a recombinant inbred line (RIL) population and develop new restorer germplasm for BNS (Bainong sterility) hybrid wheat, this study utilized 120 F₄ RIL families derived from a common wheat cross (Bainong Aikang 58×CL0442). Twelve key agronomic traits, including plant height, panicle exertion length, length of the top internode, tiller angle, spike length, spike number, productive tiller number, grain number per main spike, spikelet number, grain weight per spike, grain yield per plant, and thousand-grain weight, were systematically investigated and subjected to analyses of variability, correlation, principal components, and systematic clustering. The results revealed rich genetic diversity within the population for most traits, with evident transgressive segregation. Correlation analysis indicated a highly significant positive correlation between plant height and grain yield per plant, a significant negative correlation between the length of the top internode and grain weight per main spike, and a significant positive correlation between panicle exertion length and grain weight per spike. Principal component analysis extracted the first six principal components, which collectively accounted for 83.37% of the total variance, representing key genetic dimensions such as biomass and plant yield, spike fertility, plant height structure, and plant architecture. Cluster analysis categorized the 120 families into two major classes and four subgroups, revealing significant genetic differentiation within the population. Furthermore, a comprehensive evaluation identified eight superior lines, including R8 and R12, which exhibited outstanding overall performance, providing valuable intermediate materials for breeding strong restorer lines for BNS hybrid wheat.

In order to screen salt-tolerant germplasm of oat, 200 oat germplasm resources were subjected to complexed salt stress (NaCl∶Na₂SO₄∶NaHCO₃∶Na₂CO₃ = 1∶9∶9∶1). Six germination indices such as seed vigor index, shoot length and root length were measured. The salt-tolerant ability of oat was comprehensively evaluated by principal component analysis (PCA) and cluster analysis. The results showed that the combined saline-alkali stress significantly inhibited the germination and early growth of oat germplasm. The germination rate, germination energy, root length, shoot length, and seed vigor index all decreased to varying degrees, among which the vigor index decreased the most, while the salt damage rate increased significantly. Two principal components were extracted by PCA, and the cumulative variance contribution rate was 81.57%. Principal component 1 exhibited a higher loading on seed vigor index, shoot length, root length, and germination rate, reflecting traits related to the germination potential of oats. Principal component 2 was mainly associated with salt injury rate and root length, reflecting the tolerance performance of seeds under salt-alkali stress. Based on the comprehensive evaluation value (D value) in clustering analysis, the germplasms were classified into five groups: highly salt-alkali tolerant group (D≥0.850, 2 germplasms), salt-alkali tolerant group (0.850>D≥0.720, 2 germplasms), moderately salt-alkali tolerant group (0.720>D≥0.460, 15 germplasms), salt-alkali sensitive group (0.460>D≥0.305, 58 germplasms), and extremely salt-alkali sensitive group (D<0.305, 123 germplasms). Two oat germplasm lines with high tolerance (163 and 21) and two oat germplasm lines with tolerance (B106 and B60) to salt-alkali stress were screened.

To provide theoretical basis and technical support for the promotion and application of new types of urea fertilizer, field experiments were conducted in Xuchang City, Henan Province from 2024 to 2025. Under the same nitrogen application rate (210 kg·hm^-2), five urea treatments were set up: ordinary urea (T1), humic acid urea (T2), controlled release urea (T3), stable urea (T4), and coated urea (T5). The effects of different new urea applications on winter wheat grain yield, quality, plant canopy temperature, chlorophyll, enzyme activity, nitrogen absorption and utilization, and soil available nitrogen spatial distribution were analyzed with no nitrogen application as the control (CK). The results showed that the application of the new urea types significantly improved the yield and quality of winter wheat, with T3 treatment showing the best effect. The grain yield, starch content, soluble sugar content, and protein content under T3 treatment significant increased by 2.90%, 29.64%, 34.38% and 18.45%, respectively, compared to T1 treatment. The chlorophyll content and activities of glutamate synthase, glutamine synthase, glutamate dehydrogenase, and nitrate reductase in wheat increased under T2-T5 treatment, but the average canopy temperature decreased, and T3 treatment showed better results. Compared with the T1 treatment, the apparent recovery efficiency of nitrogen, agronomic efficiency of nitrogen, and partial factor productivity of applied nitrogen under the T3 treatment increased by 27.01%, 2.88%, and 14.42%, respectively. In addition, T3 treatment effectively increased the available nitrogen content in the 0-100 cm soil, enhancing the soil inorganic nitrogen and absorption accumulation efficiency of winter wheat soil. The application effect of controlled release urea was the best in this experiment.

To screen the optimal mulching cultivation method for dryland wheat to improve water use efficiency and yield, a long-term positioning experiment was carried out in Yongshou County on the Weibei dryland for 12 growing seasons (2012—2024). Four treatments were set up: no mulching control (CK), straw mulching (SM), ridge mulching with furrow sowing (RMFS), and plastic film mulching (PFM), to systematically evaluate the long-term effects of different mulching methods on dryland wheat yield formation and water use. The results showed that compared with CK, the average wheat yield over the 12 growing seasons increased by 9.0%, 2.7%, and 12.7% under SM, RMFS, and PFM treatments, respectively, and biomass increased by 5.5%, 1.8%, and 12.8%, respectively. Compared to CK, the average pre-sowing soil water storage of SM, RMFS, and PFM increased by 7.4%, -0.3%, and 5.7%, respectively; the average post-harvest soil water storage of SM, RMFS, and PFM increased by 8.4%, 9.5%, and 4.4%, respectively; the average summer fallow soil water storage of SM, RMFS, and PFM increased by 23.5%, 2.3% and 16.0%, respectively. Compared to CK, RMFS and PFM increased surface soil temperature by 0.3-0.5 ℃, while SM decreased surface soil temperature by 0.4-0.6 ℃. Crop water consumption during the growing period under SM, RMFS, and PFM increased by 12.2%, 6.3%, and 8.0%, compared with CK, precipitation use efficiency increased by 6.0, -0.1, and 4.7 percentage points, and fallow period water use efficiency improved by 14.4, 0.8, and 9.1 percentage points, respectively. Comprehensive comparison indicated that PFM had the best effect on yield increase, while SM had the greatest advantage in water retention.

Late sowing is one of the primary factors restricting wheat production in the middle and lower reaches of the Yangtze River. Cultivating late-sowing-tolerant wheat varieties can effectively mitigate yield losses due to delayed sowing. To elucidate the characteristics of late-sowing-tolerant wheat varieties, this experiment compared grain yield and its components, organ development processes, and the utilization of thermal and solar resources among four wheat varieties of Yangmai 25, Yangmai 28, Yangmai 30, and Yangmai 39 under late-sowing pattern with increased planting density. The results indicated that delaying the sowing date led to a significant reduction in grain number and grain yield. Under late-sowing conditions, Yangmai 25 and Yangmai 30 exhibited significantly higher grain yields, primarily attributed to their greater spike numbers. Furthermore, Yangmai 30 exhibited significantly more grains per spike. Under late-sowing pattern with increased planting density, tiller number decreased, while tiller fertility increased significantly. Yangmai 25 exhibited significantly more tillers developed in spring season compared with other varieties, while Yangmai 30 exhibited higher tiller fertility. Although late sowing reduced leaf age and tiller number, Yangmai 25 and Yangmai 30 showed relatively faster leaf age progression and greater total tiller number. Meanwhile, late sowing significantly shortened the period from tillering to jointing and the period from anthesis to maturity. This might be unfavorable for the occurrence of tillering and the filling of grains. Among the four varieties, Yangmai 25 showed an earlier jointing stage and a prolonged duration from jointing to booting, whereas Yangmai 30 exhibited an earlier booting stage and a prolonged duration from booting to anthesis. The former helped accumulate more thermal and solar resources during the productive tillering phase, while the latter provided more time and more thermal and solar resources for floret differentiation. In conclusion, the late-sowing-tolerant varieties, Yangmai 25 and Yangmai 30, share key adaptive traits: accelerated tillering-phase development with efficient temperature and solar radiation resource capture, concomitantly with prolonged process during the productive tillering phase and sufficient accumulation of temperature and solar radiation.

To clarify the current status of winter wheat fertilization in the winter wheat-summer maize rotation area in North China, a survey on farmers' nutrient management was conducted in winter wheat planting areas in Henan, Hebei, and Shandong provinces from 2022 to 2024. The application of chemical nutrients and organic fertilizers by farmers was analyzed, and the rationality of farmers' fertilization was evaluated based on the recommended fertilization rates corresponding to different yield levels in the region and historical literature. The results showed that the average yield of winter wheat in North China was 7 947.6 kg·hm^-2, with a yield gap of 2 529.7 kg·hm^-2. The average application rates of nitrogen (N), phosphorus (P₂O₅), and potassium (K₂O) fertilizers and total nutrients were 218.8 kg·hm^-2, 127.0 kg·hm^-2, 63.0 kg·hm^-2, and 408.8 kg·hm^-2, respectively. Among the surveyed farmers, 15.7%, 58.7%, and 25.7% of farmers applied insufficient, appropriate, and excessive nitrogen, respectively; 12.9%, 47.7%, and 39.4% applied insufficient, appropriate, and excessive phosphorus, respectively; and 37.5%, 33.9%, and 28.6% applied insufficient, appropriate, and excessive potassium, respectively. The average proportion of farmers applying organic fertilizers in winter wheat cultivation was 30.4%, among which the proportion of farmers applying commercial organic fertilizers was 10.0%, with an application rate of 1.5 t·hm^-2; the average input proportion of farmyard manure (including manure and straw) was 23.0%, with an input rate of 11.8 t·hm^-2. The average yield of winter wheat in the winter wheat-summer maize rotation area in North China achieved 75.9% of the yield potential, indicating significant potential for further yield improvement. The main issue with nitrogen fertilizer application was over-application, but for high-yielding farmers who were also nitrogen-deficient. The main problem with phosphorus fertilizer application was over-application by farmers of all yield levels. The main issue with potassium fertilizer application was over-application by medium and low-yielding farmers and under-application by high-yielding farmers. Overall, potassium application was insufficient. The proportion of organic fertilizers applied by farmers was relatively low. Targeted scientific fertilization technology promotion should be carried out based on the characteristics of different yield levels and the current application status of the three nutrients.

To provide a basis for formulating carbon and nitrogen reduction measures for wheat production in Jiangsu Province, a carbon and nitrogen accounting boundary for Jiangsu's wheat production system was constructed, analyzing the resource input characteristics and carbon and nitrogen footprint trends from 2014 to 2023, based on the life cycle assessment method. The results indicate that over the decade, the cost per unit area and per unit yield in Jiangsu's wheat production system showed an upward trend. Agricultural input costs were primarily attributed to fertilizers (33.38%-40.06%) and machinery (30.21%-35.72%). The per unit area carbon footprint and per unit yield carbon footprint of wheat were 2.52 t·hm^-2 and 0.46 t·t^-1, respectively, while the per unit area nitrogen footprint and per unit yield nitrogen footprint were 103.96 kg·hm^-2 and 18.89 g·kg^-1. The carbon footprint generally exhibited an increasing trend over time, with an annual growth rate of 2.23%, while active nitrogen emissions showed little variation. In the carbon footprint composition, fertilization and machinery (irrigation and diesel) were the primary sources of wheat carbon emissions, contributing 63.70% and 22.38% to total emissions, respectively. Ammonia (NH₃) volatilization was the main pathway for active nitrogen emissions in wheat production. The per unit yield carbon and nitrogen footprints were significantly negatively correlated with wheat yield. Overall, reducing carbon emissions in wheat fertilization and mechanical operations, along with increasing straw carbon sequestration, are key strategies for lowering wheat production carbon and nitrogen footprints. Measures such as promoting organic fertilizer substitution for chemical fertilizers, integrated water and fertilizer management, straw return, and the use of lightweight agricultural machinery can enhance fertilizer efficiency and mechanical productivity, thereby reducing carbon and nitrogen emissions in wheat production and achieving green, low-carbon, and sustainable development.

Solar-induced chlorophyll fluorescence (SIF) is tightly coupled with plant photosynthetic functioning and provides a sensitive indicator of vegetation stress. To address the issue of data redundancy that arises during the process of building models directly using raw full-band SIF data, this study first performed correlation analysis on the full-band SIF to identify wavelength regions that are most responsive to wheat stripe rust severity level (SL). Based on the selected sensitive bands, six SIF spectrum indices were subsequently developed through mathematical transformations, including the reciprocal SIF spectrum index (RSI_SIF), logarithmic SIF spectrum index (LSI_SIF), reciprocal logarithmic SIF spectrum index (RLSI_SIF), first order differential SIF spectrum index (FDSI_SIF), sum SIF spectrum index (SSI_SIF), and differential SIF spectrum index (DSI_SIF). Subsequently, the correlations between each index and SL were evaluated, and indices showing stronger associations with SL were selected to develop wheat stripe rust remote sensing monitoring models using random forest regression (RFR) and support vector regression (SVR), which were further validated with independent samples. The results indicated that, all SIF spectrum indices showed stronger correlations with SL than the raw full-band SIF data and the single-band FRSIF datas. Among them, LSI_SIF exhibited the highest sensitivity to SL, achieving correlation improvements of 91% relative to far-red SIF (FRSIF) and 72% relative to the original full-spectrum SIF. In terms of predictive performance, models driven by the SIF spectrum indices generally outperformed those based on FRSIF or untransformed full-spectrum SIF, while RFR delivered superior overall accuracy compared with SVR across experiments. In the controlled plot experiment, the RFR model using full-spectrum SIF as predictors increased R² by 42% and reduced RMSE by 22%, compared with the FRSIF-based model. Moreover, RFR models incorporating RSI_SIF, LSISIF, RLSI_SIF, and SSI_SIF further improved R² by 19%, 21%, 22%, and 21% over the full-spectrum SIF model, accompanied by RMSE reductions of 19%, 22%, 23%, and 22%, respectively. In the field experiment, the corresponding RFR models achieved additional gains in R² of 28%, 27%, 30%, and 23% relative to the full-spectrum SIF model, while decreasing RMSE by 21%, 20%, 22%, and 19%, respectively. Overall, these findings suggest that SIF spectrum indices constructed through mathematical transformations of full-spectrum SIF can effectively enhance the disease-related signal, leading to more accurate and robust estimates of wheat stripe rust severity. The consistent improvements observed across the controlled plot experiment and the field experiment further highlight the stability and potential transferability of the proposed indices, supporting their applicability for operational remote sensing-based crop disease monitoring.

To explore the structural differences of 1RS arms in wheat-rye 1BL·1RS translocation cultivars (lines), the 1BL·1RS translocation cultivar Nanmai 618 was used as parent to hybridize with 13 1BL·1RS translocation cultivars (lines), including Aikang 58, Chuannong 17 and Lankao Aizao 8, as well as the 7DL·1RS translocation cultivar Lumai 8. A total of 14 types of F₁ plants were obtained. High-GC content oligonucleotide probes (Oligo-119.2-2, 200G, 250G) and high-AT content oligonucleotide probes (Oligo-119.2-3, 200T, 250T) were designed based on the tandem repeats pSc119.2, pSc200, and pSc250. These probes were used in non-denaturing fluorescence in situ hybridization (ND-FISH) analysis for identifying the metaphase chromosomes of root tips from these F₁ plants. The results showed that, except for Oligo-119.2-3 which produced no signal, the other five probes generated signals with varying intensities on 1RS chromosome arms from different sources. The signal intensities of probes 200G and 200T on 1RS exhibited consistent variation trends, while the variations reflected by 250G and 250T were inconsistent. For example, 250T showed distinct signal intensities on 1RS from different sources, whereas 250G displayed similar signal intensities on the corresponding 1RS arms. These findings indicated that there were differences in the GC and AT base contents of the pSc250 tandem repeated family in 1RS among different cultivars. According to the variation in signal intensity of the probes on 1RS, the 1RS arms in these 15 wheat cultivars (lines) could be classified into four structural types. The results of this study revealed the structural variations of 1RS, which enriches the understanding of 1BL·1RS translocation chromosomes in wheat cultivars (lines) in China.