Owing to rich in vitamins, proteins, mineral elements, and active substances, the highly medicinal and economic value of mung bean seeds have been proven to be beneficial to human. In order to fully identificate and innovative utilization of excellent germplasm resources for mung bean yield and quality breeding, the genetic diversity level of eight seed phenotypic traits of 302 mung bean germplasm resources were comprehensively evaluated by diversity analysis, correlation analysis, principal component analysis (PCA), and cluster analysis. The results showed the genetic diversity of eight seed phenotypic traits of 302 mung bean germplasm resources with a Shannon diversity Index ranging from 0.25 to 2.09. For most traits, their coefficient of variation (CV) were more than 10% with the highest being seed shape (41.51%). Correlation analysis showed that the 100-seed weight had extremely positive correlations with seed size, seed length, seed width, and seed thickness. PCA of seed phenotypic traits showed that the cumulative contribution rate of the first three principal components was 78.551%. These principal components included seed width, seed coat gloss and seed color. The 302 mung bean germplasm resources were divided into eight groups by cluster analysis. A total of 140 germplasm resources with large-seed were selected from group I and group II, of which 9 germplasm resources in group II were likely to be high-yield varieties. Overall, this study not only indicated sufficient variation among the studied germplasm resources, but also provided a theoretical basis for the selection, utilization and hybrid breeding of mung bean germplasm resources.

Although the JmjC domain-containing histone demethylases displayed a crucial role in maintaining the homeostasis of histone methylation, while the systematic identification and functional researches of JmjC domain-containing gene family have not been conducted in Mung bean (VrJMJgenes). According to the structural characteristics and phylogenetic relationship with their orthologs from Glycine max, Lotus japonicus, Medicagotruncatula, Arabidopsis thaliana, and Oryza sativa, a total of 18 VrJMJgenes were identified and divided into four clades (KDM3, KDM5. PKDM8, and PKDM9). Interspecies co-collinearity analysis showed the significant JmjC gene duplication events which have occurred during the Papilionoideae evolution. The exon/intron and domain organization of VrJMJgenes from the same clade (or subclade) were similar. All VrJMJ proteins contained a conserved JmjC domain, meanwhile other essential domains also have been found in some specific VrJMJ proteins which responsible for their functions. Numerous abiotic stress and light response related cis-elements associating with transcriptional regulation that were demonstrated in the promoter regions of VrJMJgenes(Pro _VrJMJs ). Expression profiles of VrJMJgenes in different tissues showed that most genes displayed a tissue-specific expression in roots or leaves. The acronym RT-qPCR results showed that all VrJMJ genes displayed different degrees of abiotic stress (drought, salinity, and cold) and photoperiodic responses. Furthermore, VrJMJ3 and VrJMJ9 were significantly up-regulated after all three abiotic stress treatments, and VrJMJ13 exhibited a potential function in the photoperiodic regulation of Mung bean flowering. These results provided a clear understanding of VrJMJ genes, and laid a theoretical basis for further verification of their potential biological functions of VrJMJ genes.

Residue incorporation is a universally accepted agronomic practice around the world. However, the relationship between C and N turnover in soil is still not fully understood. We performed a soil microcosm incubation experiment to study the effects of residue incorporation with different C-to-N ratios (C/N) (low, 31.8; high, 84.5) on the SOC distribution, diazotrophic bacterial composition, and N accumulation in different particle size fractions (PSFs) of three types of soil parent material with different native C/N ratios. Our results demonstrate that SOC is 1.34 to 2.50 times more easily retained and accumulated in clay compared to baseline levels at the early stage of soil development. The native C/N ratio markedly affects the microbial metabolic characteristics and the SOC accumulation processes. Specifically, low C/N residue enhanced SOC accumulation in high-native-C/N soil, while the high-C/N residue maximized SOC in low-native-C/N soil. These shifts regulated the composition of the diazotrophic bacterial community, increasing the nitrogenase coding gene (nifH) abundance 5.57- and 8.1-fold in low-C/N residue treatments and 6.6-fold in the high-C/N residue treatment, thereby promoting soil N accumulation. Moreover, we highlight the potential role of Bradyrhizobiaceae, Rhodospirillaceae, Micrococcaceae, Rhizobiaceae, Comamonadaceae, Nitrospiraceae, and Burkholderiaceae in biological N fixation during pedogenesis. This study explored the coupling relationship between soil native and residue C/N and soil biological N fixation at the soil particle level, and the results suggest that residue incorporation to improve soil fertility needs to be further explored according to soil native C/N.

Vetiver grass (Chrysopogon zizanioides), is a perennial and tussock C4 grass from the genus Chrysopogon of Poaceae, which has been widely used as a natural and inexpensive resource for multifarious environmental applications. The complete mitogenome of C. zizanioides was 551,622 bp in length, containing 40 protein-coding genes (PCGs), 19 transfer RNA genes (tRNAs), and six ribosomal RNA genes (rRNAs). All PCGs started with ATG and stopped with TNN (TAA, TAG, and TGA). The overall nucleotide composition is: 28.2% A, 28.2% T, 21.7% G, and 21.9% C, with a biased A + T content of 56.4%. Phylogenetic analysis using 14 PCGs of 22 species showed that C. zizanioides display a close relationship with Saccharum officinarum (LC107874) and Sorghum bicolor (DQ984518) in Poaceae.