‘DUS’ characterization of an endangered salt tolerant radish landrace (Newar)

Abstract

In this study, responses to salinity stress of three varieties of radish, viz., ‘Newar’ (landrace), ‘Pusa Mridula’ and ‘White Excel’, were recorded. Additionally, landrace Newar was also characterized for ‘Distinctness, Uniformity and Stability’ (DUS) using 34 descriptors. Results indicated higher salt tolerance in ‘Newar’ as evidenced by relatively early germination and high early seedling vigour than other varieties regardless of the salinity of the irrigation water. Although salinity stress, especially up to 8.0 dS m^-1, had no adverse effect on shoot growth in all the varieties, effects on root growth were quite different. While ‘Newar’ exhibited non-significant differences in root fresh weight (RFW) at different salinity levels, ‘White Excel’ displayed nominal variations up to 8.0 dS m^-1 salinity and ‘Pusa Mridula’ registered consistent declines in RFW with increasing salinity. ‘Newar’ plants were found to be efficient in Na⁺ exclusion and in maintaining a favourable Na⁺ to K⁺ ratio in their shoots and roots. Further, proline accumulation was much higher in salt treated Newar than in ‘White Excel’ and ‘Pusa Mridula’ plants. Based on DUS descriptors, number of leaves, leaf length, and root length and weight were found to be the major distinguishable characters in Newar.