Tamil Nadu in particular is a key rice-producing region in peninsular India. Hydrochemistry, viz., redox potential (Rh), soil temperature and dissolved oxygen (DO), of rice soils can determine the production of greenhouse gas methane (CH₄). In recent decades, the cultivation of crops organically became a viable option for mitigating climate change. Hence, this study aimed to investigate the effects of different organic amendments on CH₄ emission, Rh, DO, and soil and water temperature (T) in relation to the yield of paddy. The treatments composed of viz., control, blue-green algae (BGA), Azolla, farm yard manure (FYM), green leaf manure (GLM), blue-green algae + Azolla, FYM + GLM, BGA + Azolla + FYM + GLM, vermicompost and decomposed livestock manure. With the addition of BGA + Azolla, the highest reduction in CH₄ emission was 37.9% over the control followed by BGA. However, the same treatment had a 50% and 43% increase in Rh and DO, respectively, over the control. Established Pearson correlation analyses showed that the CH₄ emission had a positive correlation with soil (r = 0.880 **) and water T (r = 0.888 **) and negative correlations with Rh (r = −0.987 **) and DO (r = −0.963 **). The higher grain yield of 26.5% was associated with BGA + Azolla + FYM + GLM application. Our findings showed that there are significant differences in CH₄ emissions between different organic amendments and that hydro-parameters may be a more important controlling factor for methane emissions than temperature. The conclusion has been drawn based on valid research findings that bio-fertilization using BGA and Azolla is an efficient and feasible approach to combat climate change, as it assists in reducing methane emissions while simultaneously boosting crop yield by fixing nitrogen into the soil in the studied agro-climatic zone.

Yellow mosaic disease (YMD), incited by mungbean yellow mosaic virus (MYMV), is a primary viral disease that reduces mungbean production in South Asia, especially in India. There is no detailed knowledge regarding the genes and molecular mechanisms conferring resistance of mungbean to MYMV. Therefore, disclosing the genetic and molecular bases related to MYMV resistance helps to develop the mungbean genotypes with MYMV resistance. In this study, transcriptomes of mungbean genotypes, VGGRU-1 (resistant) and VRM (Gg) 1 (susceptible) infected with MYMV were compared to those of uninfected controls. The number of differentially expressed genes (DEGs) in the resistant and susceptible genotypes was 896 and 506, respectively. Among them, 275 DEGs were common between the resistant and susceptible genotypes. Functional annotation of DEGs revealed that the DEGs belonged to the following categories defense and pathogenesis, receptor-like kinases; serine/threonine protein kinases, hormone signaling, transcription factors, and chaperons, and secondary metabolites. Further, we have confirmed the expression pattern of several DEGs by quantitative real-time PCR (qRT-PCR) analysis. Collectively, the information obtained in this study unveils the new insights into characterizing the MYMV resistance and paved the way for breeding MYMV resistant mungbean in the future.

Mungbean (Vigna radiata) is an important short-season legume widely cultivated in Asia, particularly India. It is highly susceptible to bruchids and developing bruchid resistance is an important goal in mungbean breeding programs. In the present study, 52 mungbean genotypes were evaluated for bruchid resistance based on the “no-choice test” and identified two highly resistant genotypes (V2802BG and V2709) with no adult emergence and seed damage. Further, these two resistant genotypes were crossed with six high-yielding bruchid susceptible cultivars (CO 5, CO 6, CO 7, CO 8, VBN 2, and VBN 3), and 12 independent F₁ populations were generated. Of these, one population derived from CO 6 × V2802BG was selected (based on the good combining ability of the parents) and forwarded to later generations to trace the bruchid-resistant lines. A total of 159 F_2:3 families were screened for bruchid resistance, and the results showed that seven families were highly resistant, whereas the remainder were resistant to highly susceptible. Further, those seven families were evaluated in F₄ and F₅ generations. As a result, five highly resistant lines (BSR-GG-1-49-3-1, BSR-GG-1-56-2-2, BSR-GG-1-160-5-3, BSR-GG-1-170-2-4, and BSR-GG-1-198-1-4) with good agronomic performances were identified. The newly developed lines could be tested in multi-location trials and then be utilized as a potential source of genetic material for improving the bruchid resistance in mungbean breeding programs.

Mungbean is a nutritionally and economically important pulse crop cultivated around Asia, mainly in India. The crop is sensitive to drought at various developmental stages of its growing period. However, there is limited or almost no research on a comparative evaluation of mung-bean plants at the flowering stage under drought conditions. Hence, the aim of this research was to impose the drought stress on two mungbean cultivars VRM (Gg) 1 and CO6 at the flowering stage and assess the physio-biochemical and transcriptional changes. After imposing the drought stress, we found that VRM (Gg) 1 exhibited a low reduction in physiological traits (Chlorophyll, relative water content, and plant dry mass) and high proline content than CO6. Additionally, VRM (Gg) 1 has a low level of H₂O₂ and MDA contents and higher antioxidant enzymes (SOD, POD, and CAT) activity than CO6 during drought stress. The transcriptional analysis of photosynthesis (PS II-PsbP, PS II-LHC, PS I-PsaG/PsaK, and PEPC 3), antioxidant (SOD 2, POD, CAT 2), and drought-responsive genes (HSP-90, DREB2C, NAC 3 and AREB 2) show that VRM (Gg) 1 had increased transcripts more than CO6 under drought stress. Taken together, VRM (Gg) 1 had a better photosynthetic performance which resulted in fewer reductions in chlorophyll, relative water content, and plant dry mass during drought stress. In addition, higher antioxidative enzyme activities led to lower H₂O₂ and MDA levels, limiting oxidative damage in VRM (Gg) 1. This was positively correlated with increased transcripts of photosynthesis and antioxidant-related genes in VRM (Gg) 1. Further, the increased transcripts of drought-responsive genes indicate that VRM (Gg) 1 has a better genetic basis against drought stress than CO6. These findings help to understand the mungbean response to drought stress and will aid in the development of genotypes with greater drought tolerance by utilizing natural genetic variants.

In this study, an extensive exploration survey of wild progeny was conducted which yielded 18 candidate plus trees (CPTs) of Terminalia bellerica. Seeds of these CPTs were collected from diverse locations between 10°54′ and 28°07′ E longitude, and 76°27′ and 95°32′ N latitude, covering 18 different locations across 5 states of the Indian subcontinent. The objective of the progeny trial was to assess genetic associations and variability in growth and physio-chemical characteristics. Significant variations (p < 0.05) were observed among the growth traits, encompassing plant height, basal diameter, girth at breast height and volume, as well as physio-chemical characteristics such as leaf length, width, area and chlorophyll content, carotenoids, and protein in the progeny trial. Broad-sense heritability (h²_b) estimates were consistently high, exceeding 80% for all growth and physiological related traits under investigation except for plant height, leaf length, and girth at breast height. A correlation study revealed that selecting based on plant height, leaf area, and girth at breast height effectively enhances T. bellerica volume. A moderate genetic advance in percent of the mean (GAM) was observed for most traits, except leaf length, leaf width, girth at breast height, and plant height. Across all 13 traits, phenotypic coefficient of variation (PCV) surpassed genotypic coefficient of variation (GCV). Utilizing principal component analysis (PCA) and dendrogram construction categorized the genotypes into seven distinct groups. In conclusion, the study has demonstrated that targeting girth at breast height and plant height would be a highly effective strategy for the establishment of elite seedling nurseries and clonal seed nurseries for varietal and hybridization programs in the future.