Exploring the genetic variability for root traits in mung bean under salinity stress

Mung bean (Vigna radiata L.) holds significant importance as a pulse crop contributing to food and nutritional security. It is mainly cultivated in South Asia. Mung bean productivity is hampered by different abiotic stresses, particularly salinity. Salinity is a serious constraint that restricts the growth and development of mung bean. Identification and utilization of novel sources of variation for key stress tolerance traits is required in mung bean improvement breeding. A diverse set of thirty mung bean accessions were evaluated at the seedling stage for their response towards salinity stress using hydroponic culture with two treatments: control (0 mM NaCl), and salt stress (200 mM NaCl). The genotypes revealed significant variations for the fresh weight, dry weight, shoot length, surface area, and root volume. Also the root traits; root volume, root length, root surface area, and tip number were correlated to biomass under salinity stress. The salt tolerance index varied from 0.38 to 0.91, considering the seedling vigour. Four (PUSA0971, EC937886, IC282531, IC623909) genotypes were found promising for salinity tolerance based on seedling vigour and root traits. Identified genotypes may be validated in field conditions for their further use as trait donors to develop mung bean varieties with enhanced salt tolerance.