INTEGRATED BIOCHEMICAL AND MOLECULAR CHARACTERIZATION OF CLIMATE-RESILIENT MUNGBEAN (VIGNA RADIATA (L.) R. WILCZEK) GENOTYPES FOR TOLERANCE TO TERMINAL HEAT AND WATER STRESS UNDER STAGGERED PLANTING ENVIRONMENTS

Abstract

Background: Terminal heat and water stress are major constraints affecting mungbean productivity under changing climatic conditions. The present study aimed to identify climate-resilient mungbean genotypes through integrated biochemical and molecular characterization under staggered planting environments. Methods: Five mungbean genotypes (PDM 139, Pusa Ratna, Pusa Vishal, Pusa 1431, and TJM 3) were evaluated under three sowing dates (12 February, 27 February, and 14 March) during summer seasons of 2022–23 and 2023 24 . Biochemical traits, yield attributes, and RAPD-based molecular diversity were assessed to determine stress tolerance. Result: Delayed sowing enhanced stress-related biochemical responses, while early sowing recorded higher protein content. Among the genotypes, PDM 139 produced the highest seed yield (730.42 kg ha⁻¹), with maximum yield observed under 27 February sowing (826.02 kg ha⁻¹). RAPD analysis using 25 primers generated 75 loci, of which 54 were polymorphic, with an average polymorphism of 69.49%. Cluster analysis grouped the genotypes into three distinct clusters, revealing substantial genetic diversity. Integration of biochemical and molecular data identified PDM 139 as the most promising genotype for tolerance to terminal heat and water stress. The study highlights the potential of combining biochemical and molecular markers for developing climate-resilient mungbean cultivars.