The timely and accurate estimation of above-ground biomass (AGB) is crucial for indicating crop growth status, assisting management decisions, and predicting grain yield. Unmanned aerial vehicle (UAV) remote sensing technology is a promising approach for monitoring crop biomass. However, the determination of winter wheat AGB based on canopy reflectance is affected by spectral saturation effects. Thus, constructing a generic model for accurately estimating winter wheat AGB using UAV data is significant. In this study, a three-dimensional conceptual model (3DCM) for estimating winter wheat AGB was constructed using plant height (PH) and fractional vegetation cover (FVC). Compared with both the traditional vegetation index model and the traditional multi-feature combination model, the 3DCM yielded the best accuracy for the jointing stage (based on RGB data: coefficient of determination (R²) = 0.82, normalized root mean square error (nRMSE) = 0.2; based on multispectral (MS) data: R² = 0.84, nRMSE = 0.16), but the accuracy decreased significantly when the spike organ appeared. Therefore, the spike number (SN) was added to create a new three-dimensional conceptual model (n3DCM). Under different growth stages and UAV platforms, the n3DCM (RGB: R² = 0.73–0.85, nRMSE = 0.17–0.23; MS: R² = 0.77–0.84, nRMSE = 0.17–0.23) remarkably outperformed the traditional multi-feature combination model (RGB: R² = 0.67–0.88, nRMSE = 0.15–0.25; MS: R² = 0.60–0.77, nRMSE = 0.19–0.26) for the estimation accuracy of the AGB. This study suggests that the n3DCM has great potential in resolving spectral errors and monitoring growth parameters, which could be extended to other crops and regions for AGB estimation and field-based high-throughput phenotyping.

Starch granule size distribution plays a vital role in determining the physicochemical properties and processing quality of soft wheat. This study analyzed fourteen soft wheat varieties cultivated in the Huaihe River Basin, an agriculturally important but underrepresented region, to evaluate starch granule size distribution, pasting properties, and their interrelationship. The starch granules were categorized into four size classes, with the volume dominated by A-type granules (>10 μm), while numerically, the majority were 10 μm showed a positive correlation with peak viscosity (r = 0.53 *), final viscosity (r = 0.57 *), and set-back (r = 0.53 *), while the volume percentage of granules < 10 μm was significantly negatively correlated with peak viscosity (r = −0.53 *), final viscosity (r = −0.57 *), and set-back (r = −0.53 *) value. It indicated that the higher the percentage of granules > 10 μm, the higher the peak viscosity, final viscosity, and set-back value in soft wheat grain.

Increasing nitrogen fertilizer will increase wheat grain yield and grain quality at the same time, but the goal of high quality and stable yield in weak-gluten wheat production is to reduce grain protein content and increase grain yield. Our research goal is to reduce nitrogen input while increasing planting density to maintain high quality and stable yield. Field studies were conducted during two successive seasons using a widely planted cultivar, Yangmai 15. We studied the effects of reduced nitrogen topdressing and increased planting density on yield, quality and nitrogen agronomic efficiency. The field experiment was conducted with four nitrogen (N) levels for topdressing at jointing stage: 37.8 (N1), 43.2 (N2), 48.6 (N3) and 54 kg N ha⁻¹ (N4). Moreover, there were three planting densities: 180, 240 and 300 × 10⁴ plants ha⁻¹ (D1, D2 and D3, respectively). When the amount of nitrogen topdressing was reduced, the number of tillers and spikes in each growth period of wheat decreased significantly, and the yield increased first and then decreased, with the highest yield at the level of 48.6 kg N ha⁻¹. When the planting density was increased, the number of tillers and spikes in each growth period of wheat increased significantly, the yield increased significantly, and the yield was the highest at the level of 180 × 10⁴ plants ha⁻¹. Under the same density level, the flag leaf chlorophyll content, leaf area index, nitrogen production efficiency and nitrogen use efficiency decreased with a decrease in the nitrogen application rate. Under the same nitrogen topdressing amount, the nitrogen fertilizer production efficiency and nitrogen fertilizer utilization efficiency increased with the increase in density. The relative chlorophyll content, leaf area index, nitrogen partial factor productivity, nitrogen use efficiency, grain accumulation, grain distribution ratio and grain yield of wheat were the highest under the treatment of a planting density of 300 × 10⁴ plants ha⁻¹ and nitrogen topdressing amount of 48.6 kg N ha⁻¹. The combined decrease in nitrogen recovery and increase in planting density decreased protein content, sedimentation value and wet gluten content. Increasing density significantly improved dry matter accumulation in the population, partially compensating for the yield loss due to nitrogen reduction by increasing the effective number of spikes, thereby further improving grain quality and nitrogen use efficiency. Therefore, agronomic approaches combining low nitrogen and high planting densities may be effective in simultaneously increasing grain yield and nitrogen use efficiency and stabilizing grain processing quality in weakly reinforced wheat.

Boehmeria nivea (ramie) is an important fiber crop with strong tolerance to cadmium (Cd). In our previous study, a novel MYB transcription factor gene from ramie, BnMYB2, was found to positively regulate Cd tolerance and accumulation in the transgenic Arabidopsis thaliana lines. Herein, transcriptome sequencing was performed to identify the differentially expressed genes involved in cadmium response between the wild-type (WT) and BnMYB2 overexpressed lines; 1598 differentially expressed genes (DEGs) were detected in the shoot. GO and KEGG analysis indicated that the majority of DEGs belonged to the categories of transcription factors, plant hormone signal transduction and nitrogen metabolism. The expression level of the Ib subgroup bHLH genes (AtbHLH38, AtbHLH39, AtbHLH100 and AtbHLH101) and nitrogen assimilation-related genes (AtNIA1, AtNIA2, AtNIR1 and AtASN2) were significantly higher than that of WT, accompanied with the positive changes in iron (Fe) and total nitrogen content in the shoot of BnMYB2 overexpression lines. Several DEGs belonging to the bZIP transcription factor family or SAUR family were also found up-regulated in the transgenic plants. These results provide important clues for elucidating how the molecular mechanisms of BnMYB2 regulate plant response to Cd stress.

This study examined the effects of nitrogen (N) application rates and weak light treatment post anthesis on the grain yield and starch physicochemical characteristics of soft wheat. The soft wheat varieties Quanmai 725 (QM725) and Yangmai 15 (YM15) were used as study materials under field conditions, and the experiments were conducted during 2022–2023. During the grain filling stage (7–35 days post anthesis), three shading levels were set: 10% shading (S1), 20% shading (S2) and 30% shading (S3), with natural light conditions used as the control (CK). In 2023–2024, two N application rates (120 kg/hm² [N1] and 180 kg/hm² [N2]) and the abovementioned three shading treatments for each N application rate were set during the filling stage. The effects of weak light treatment post anthesis on the grain yield and yield components of soft wheat were analyzed. Moreover, the mitigation effects of different N application rates on the grain yield and starch physicochemical characteristics of wheat were examined. The results showed that N application increased wheat yield and yield components as well as the content of starch and its components, whereas weak light treatment decreased these parameters under the same N application rate. Under N1 and N2 conditions, weak light treatment post anthesis significantly reduced the volume, surface area percentage and number of B-type starch granules (particle size ≤10 μm) and increased those of A-type starch granules (particle size >10 μm). Enhanced N application rates significantly improved the gelatinization characteristics and thermodynamic characteristics of wheat starch. Under the same conditions of N1 and N2, weak light treatment significantly reduced the gelatinization characteristics of wheat starch, such as peak viscosity, trough viscosity and final viscosity. Although the enthalpy of wheat starch was increased, its onset temperature, peak temperature and end temperature were significantly reduced, which affected the quality of wheat grains and eventually led to a decrease in wheat yield. However, enhanced N application rates increased the grain yield and starch physicochemical characteristics of wheat. Under the same N application rate, weak light treatment post anthesis reduced the content of starch and its components in wheat grains, which in turn affected the wheat grain weight. The effect was more pronounced in wheat B-type starch granules than in A-type starch granules.

Genetic transformation is a core technology for wheat molecular breeding. Transformation efficiency and genotype compatibility determine the pace of targeted genetic improvement. Mature embryos are readily accessible but are associated with low transformation efficiency and strong genotype dependence. Using mature wheat embryos as explants, we screened eight wheat varieties representing three ecological types to develop genotype-adapted tissue culture systems. Treatments A5 (4 mg/L 2,4-D + 2 mg/L Dicamba), A7 (4 mg/L 2,4-D + 6 mg/L Dicamba), and A8 (4 mg/L 2,4-D + 8 mg/L Dicamba) were optimal for callus induction in winter, semi-winter, and spring wheat, respectively. WF3 (a 1/2 MS-based medium) was broadly applicable to callus differentiation, whereas IBA produced the highest rooting efficiency in regenerated plantlets. The optimal transformation conditions comprised ultrasound treatment (2.5 min) followed by vacuum infiltration (5 min), supplementation of the infection solution with PEG₆₀₀₀ (250 mg/L) and Tween20 (0.01%), and an OD₆₀₀ of 0.6–0.8. Transformation efficiencies using mature embryos of the semi-winter wheat varieties YX288 and ZM578 were 2.5% and 1.8%, respectively. Using this transformation platform, the dwarfing genes Rht12 in ZM578 and Rht8 in YX288 were targeted by CRISPR/Cas9-mediated editing. Multiple single-base substitutions at the target sites were detected in ZM578 rht12 mutants, which exhibited significantly reduced height, increased tiller number, and a compact plant architecture. However, no successfully edited rht8 lines were obtained in YX288. These findings indicate that this study established a reliable mature-embryo transformation system for wheat and successfully validated gene editing in the semi-winter variety ZM578. The system provides a technical platform for the functional analysis of key genes and molecular breeding in bread wheat.