Effect of salinity on growth traits in sorghum (Sorghum bicolor)

Abstract

The experiment was conducted to study the effect of salinity on growth characters in sorghum at Punjab Agricultural University, Ludhiana during Kharif 2020. In this experiment, 40 sorghum genotypes were grown hydroponically under control (EC 2.0 dS/m) and three salt stress concentrations (EC 6.8 dS/m, EC 11.4 dS/m and EC 16.2 dS/m). To study the effect of salt stress, the data was recorded on six growth parameters viz., per cent germination, seedling shoot/root ratio, seedling fresh weight, seedling dry weight, stress tolerance vigour index I and stress tolerance vigour index II with respect to seed vigor index. Based on germination percentage, it was noticed that 19 genotypes failed to germinate at EC 16.2 dS/m. It was further observed that the increase in salt concentration had drastic effect on all the growth characters studied. The genotype with minimum decrease in shoot/root ratio under salt stress was SCL3. Based on salt tolerance indices with respect to seedling vigor index, SPSSV40 was found to be most tolerant. Further, the cluster analysis performed on the basis of mean comparisons of all growth traits grouped the genotypes into six categories viz., highly tolerant, moderately tolerant, tolerant, susceptible, moderately susceptible and highly susceptible. Eleven genotypes among the 40 genotypes studied were found to be tolerant with four genotypes being highly tolerant to salt stress. The genotypes SPSSV40, PV2068, SCL3 and UK081 were found to be highly tolerant which can be used in further breeding programs while developing genotypes for salt stress tolerance.