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.