Genome-wide association study delineating genomic regions contributing to heat stress tolerance at vegetative stage in mung bean [Vigna radiata (L.) R. Wilczek]

Mung bean [Vigna radiata (L.) R. Wilczek] is a vital grain legume crop valued for its high protein content, essential vitamins, and micronutrients. However, increasing occurrences of heat stress pose a significant challenge to its production. While substantial research has explored physiological and biochemical responses to heat stress, there remains a limited genomic insights into heat stress tolerance in mung bean. This study employed a genome-wide association study to identify genomic regions and candidate genes associated with heat stress tolerance during the vegetative stage. A globally diverse panel of 396 genotypes was evaluated under optimal (34/25°C) and heat stress (42/30°C) conditions, assessing six major morpho-physiological traits. Through genome wide association mapping analysis we identified nine significant marker trait associations (MTAs) under optimal conditions and 12 under heat stress. Eleven putative candidate genes were identified, including those encoding phytochrome A-like proteins, leucine-rich repeat extension-like proteins, and calcium ATPases. These findings highlight key genomic regions and biological pathways involved in heat stress tolerance, providing valuable genomic resources for marker-assisted breeding to develop heat-resilient mung bean cultivars.