EVALUATION OF MUNGBEAN GENOTYPES IN RESPONSE TO SALINITY STRESS

Abstract

A study was conducted to assess the response of 21 mungbean genotypes (L1 to L21) to varying salinity stress levels (0 mM NaCl - control, 100 mM NaCl, and 150 mM NaCl) in the net house of the Department of Genetics and Plant Breeding at Sher-e- Bangla Agricultural University, Dhaka, from January 2022 to March 2022. The experimental design employed was Completely Randomized Design (CRD) with three replications. The research was divided into two distinct experiments. In the first experiment, the genotypes were screened-out based on their Salt Tolerant Trait Index (STTI) for growth and morphological parameters. Increasing salinity levels were found to have a negative impact on mungbean growth and morphological traits. Genotypes were classified into four groups: tolerant (L1, L13, L17, L18, L19, and L21), moderately tolerant (L6, L10, L12, and L12), moderately susceptible (L4, L8, L11, L14, L15, and L16), and susceptible (L2, L3, L5, L7, and L9). The second experiment focused on six selected genotypes (L2, L8, L12, L18, L19, and L21) from the first study, evaluating their physiological and biochemical responses. Genotypes L18, L19, and L21 consistently exhibited higher chlorophyll levels, indicative of enhanced salt stress resilience. L18 and L21 demonstrated better K+ maintenance, while L19 consistently displayed higher catalase and peroxidase activity, suggesting a robust response to salt stress. Some genotypes (L12, L18, and L21) displayed increased polyphenol content under saline stress conditions, implying potential salt stress tolerance. In summary, genotypes L18, L19, and L21 consistently excelled in multiple parameters under salt stress in both experiments. These genotypes hold promise for developing salt-tolerant mungbean varieties, contributing to agricultural sustainability in saline-prone regions. Further research is suggested to fully explore their breeding potential.