Molecular mechanism of salt tolerance for genetic diversity analysed in association with Na + /K + ratio through SSR markers in rice (Oryza sativa L.)

Abstract

In the present study, genotyping through microsatellite markers for salinity tolerance in a set of twenty five genetically divergent genotypes and phenotyping for Na + /K + ratio grown under Yoshida solution with 60 and 120 mM NaCl and the mechanism behind the association was detected. The polymorphic SSR markers already reported for major saltol QTLs was utilized in these studies revealed highly reproducible. The cluster and principal component analysis allowed a clear grouping of 25 genotypes grouped into 8 distinct clusters of resistant and susceptible genotypes with high and low level of Na + /K + ratio. There was a highly significant correlation (R 2 = 88.75; p = 5%) between the SSR markers and physiological trait based on ion analysis. The association of SSR markers viz., RM 23, 493 and 8053 for the trait linked to Na + /K + ratio can be regarded as the most reliable markers for marker-assisted selection to identify salinity tolerance in rice. The study revealed that the selection of genetically diverse and resistant genotypes based on association of Na + /K + ratio with molecular markers is reliable. These markers can also be used to screen large set of germplasm collection to identify and discriminate more salt tolerant rice genotypes from susceptible based on sequence homology with already identified salt tolerant rice genotypes, which can be utilized as donors in the breeding programme for generating salt tolerant varieties.