Genetic variability for seedling stage salinity tolerance in barnyard millet [Echinochloa frumentaceae (Roxb.) Link]

Barnyard millet (Echinochloa frumentaceae) has a potential to withstand salinity. The existing genetic variability for salinity tolerance in 32 barnyard millet accessions was assessed based on the morpho-physiological parameters governing salt tolerance viz., germination percentage, relative germination rate, root length, shoot length, seedling length, vigour index, relative salt injury rate and relative water content. Under gradual increase in the intensity of salt stress, decrease in germination percentage, relative germination rate, root length, shoot length, seedling length, vigour index, relative water content and increase in relative salt injury rate was observed. The antioxidant assay also revealed that catalase and peroxidase activity increased with rise in salt level in tolerant genotypes (ACM161, ACM295, ACM335, GECH10, IEc167) but the enzyme activity in the salt sensitive genotypes (IEc134, IEc348, IEc607) declined with increase in salt concentration, when compared to control. The salt tolerant genotypes maintained higher relative water content and enzyme activity under salt stress. Hence, this may be the underlying mechanism for salt tolerance.