Soil salt-alkalization seriously impacts crop growth and productivity worldwide. Breeding and applying tolerant varieties is the most economical and effective way to address soil alkalization. However, genetic resources for breeders to improve alkali tolerance are limited in mung bean. Here, a genome-wide association study (GWAS) was performed to detect alkali-tolerant genetic loci and candidate genes in 277 mung bean accessions during germination. Using the relative values of two germination traits, 19 QTLs containing 32 SNPs significantly associated with alkali tolerance on nine chromosomes were identified, and they explained 3.6 to 14.6% of the phenotypic variance. Moreover, 691 candidate genes were mined within the LD intervals containing significant trait-associated SNPs. Transcriptome sequencing of alkali-tolerant accession 132–346 under alkali and control conditions after 24 h of treatment was conducted, and 2565 DEGs were identified. An integrated analysis of the GWAS and DEGs revealed six hub genes involved in alkali tolerance responses. Moreover, the expression of hub genes was further validated by qRT-PCR. These findings improve our understanding of the molecular mechanism of alkali stress tolerance and provide potential resources (SNPs and genes) for the genetic improvement of alkali tolerance in mung bean.

Mung bean (Vigna radiata) plays a significant role in agricultural trade, food processing and utilization, and cropping structure adjustment due to its abundant nutritional components, medicine-food homology, capacity for nitrogen fixation, and soil improvement. The low yield level is a crucial limitation factor in the mung bean industry, while heterosis is an efficient path for increasing crop yields. The flexible utilization of male sterile mung bean materials may solve this pressing demand in the industry. This study identified a completely male-sterile mutant, vrnp 1, in the EMS-mutagenized mung bean cultivar Jilv 10 population, which is controlled by a single recessive nuclear gene. Furthermore, we employed a series of microscopical and histological techniques and observed that the tapetal cells in the vrnp 1 mutant did not perform as expected when reaching stage 8 of anther development, notably exhibiting a delay in entering PCD. This was accompanied by a failure to deposit cell wall components onto the pollen wall, culminating in a complete absence of mature pollen and the manifestation of male sterility. In conclusion, the vrnp 1 mutant could potentially serve as a promising candidate for male sterility in exploiting hybrid vigor in mung bean. Our research may elucidate how the delayed initiation of programmed cell death in tapetal cells contributes to a factor implicated in mung bean male sterility. Furthermore, the phenotypic data collected during pivotal developmental phases may have contributed to a better grasp of mung bean microspores and anther development.

Enhancing technical efficiency in food legume production is essential, since the scope for expanding factor inputs is limited under tightening resource constraints. Higher technical efficiency improves resource allocation, ensures food supply stability, and boosts farm income. To strengthen production performance, using survey data from 817 food legume farm households in five major producing regions of China in 2024, this study employs a two-stage DEA-Tobit model to measure farmers’ technical efficiency in food legume production and to empirically identify its driving factors. The results indicate that: (1) technical efficiency in food legume production shows pronounced regional disparities and substantial within-region heterogeneity; (2) technical efficiency in food legume production improves over time, yet substantial space for efficiency gains remains relative to other staple crops; (3) farm households located at different stages of returns to production inputs show distinct production and management patterns. (4) human capital accumulation, full-time farming status, and participation in food legume cooperative economic organizations exert significant positive effects on technical efficiency. Meanwhile, planting scale exhibits a significant inverted U-shaped relationship with technical efficiency. The findings provide household-level empirical evidence to explain disparities in technical efficiency and identify pathways for improving food legume production.

Stigma exsertion has been widely used in hybrid breeding as an excellent trait to improve crop outcrossing rate, seed purity, and seed production cost. As a closed-pollinated crop, few stigma exsertion mutants have been reported in mungbean. A stigma exsertion mutant se2 was discovered in mungbean variety Jilyu 7 after chemical mutagination. In order to clarify the molecular mechanism of stigma exsertion, transcription-sequencing (RNA-seq) analysis was conducted on the next day's opening buds of se2 and its wild type Jilyu 7. A total of 572 differentially expressed genes (DEGs) were obtained in se2, among which 262 DEGs were up-regulated and 310 DEGs were down-regulated, based on the screening criteria of difference multiplier |log2(Fold Change)| ≥1 and P ≤ 0.05. In GO database, differentially expressed genes were significantly enriched in biological processes such as metabolism and biosynthesis, and localized in regions such as apoplast, cell walls, and membranes, and mainly associated with molecular functions such as binding and redox. In the kyoto encyclopedia of genes and genome (KEGG) database, differentially expressed genes were significantly enriched in plant hormone signal transduction and biosynthesis of secondary metabolites. Functional annotation revealed many genes related to cell wall synthesis and metabolism, cell division and cell expansion, and plant hormones. Therefore, we hypothesized that cell division, cell expansion, and plant hormone signaling processes of the keel flap in se2 mutants were affected, leading to stigma exsertion. This study laid a foundation for future investigations into the molecular mechanism of stigma exsertion in mungbean and its application in heterosis.