Screening of Some Rice (Oryza sativa L.) Genotypes for Salinity Tolerance using Morphological and Molecular Markers

Abstract

Salinity is one of the major abiotic stresses, which adversely affects the crop productivity. Thirty rice genotypes of diverse origin including three salt tolerant check varieties, Binadhan-8, Binadhan-10 and Pokkali, were used to evaluate salt tolerance at seedling stage and to determine the genetic diversity using microsatellite markers. Salinity screening was done at the seedling stage using hydroponic system following IRRI standard protocol. Three salinity levels as 6dSm-1, 8dSm-1, and 10dSm-1 were used along with control. Data were recorded on root length, shoot length and dry weight and the genotypes were scored based on modified standard evaluation score (SES) for visual injury. Sixteen SSR markers were used to study the genetic variation within 30 rice genotypes. A total of 65 alleles with an average of 4.06 allele per locus were detected among 30 rice genotypes. The polymorphism information content (PIC) value ranged from 0.24 to 0.86 with an average of 0.51. The unweighted pair group method with arithmetic mean (UPGMA) dendrogram revealed four clusters. Among them cluster I identified 5 salt tolerant genotypes and cluster IV separated one tolerant and one moderately tolerant genotype. Based on SES evaluation and molecular analysis genotypes Balam, THDB, Q-31, Ab.Hai, BR-5, FR13A ware salt tolerant; Moulota, Super hybrid, Y-1281, Binadhan-16 were moderate salt tolerant. This information could be useful for selection of suitable genotypes for developing salt tolerant rice variety through molecular breeding.