Screening mungbean (Vigna radiata L.) lines for salinity tolerance using salinity induction response technique at seedling and physiological growth assay at whole plant level

Mungbean (Vigna radiata L.) is an economically important food legume rich in nutrients. However, its productivity over the last few decades has been stagnant largely due to various biotic and abiotic stresses. Among the abiotic stresses, salinity stress is more damaging that limits functional plant growth and yield worldwide. Due to the complex nature of salinity stress and lack of suitable techniques for introgression of desirable agronomic traits, little progress has been made in developing salt tolerant lines in legumes, in general and mungbean in particular. In the present investigation, an attempt has been made to screen mungbean lines for salinity tolerance. Forty mungbean lines were screened and contrasting lines were identified based on Salinity Induction Response (SIR) technique at the seedling level. As tolerance is a developmental stage specific, we further subjected the identified nine tolerant and nine susceptible lines for physiology based whole plant growth and yield phenotyping assay under 150 and 300 mM NaCl stress in pots. The results shown a considerable reduction in growth and yield performances of both tolerant and susceptible lines, but a few lines displayed relatively a better biomass and pod yield on par with non-stressed control plants. Based on seedling and whole plant level tolerance, a few tolerant (EC 693357, 58, 66, 71 and ML 1299) lines were identified for further investigation. Efforts are underway to use these identified tolerant lines as donor source for salinity breeding program to introgress with high yielding popular varieties.