Identification of New Alleles in Salt Tolerant Rice Germplasm Lines through Phenotypic and Genotypic Screening

The present study investigated eight rice lines (Rupsal, Nagalmutha, Polai, Ravana, Marishal, Talmugra, Kamini and Raspanjar) collected from coastal region of eastern India for salinity tolerance through phenotypic and genotypic screening. Among these, three rice lines as highly tolerant (Talmugra, Marishal and Kamini), three tolerant (Rupsal, Polai and Raspanjar) and two moderately tolerant (Ravana and Nagalmutha) to salt stress were identified in phenotypic screening. Pokkali was categorized as tolerant under salinity condition (12 EC dS m -1 ). In PCR screening using microsatellite (SSR) markers located within Saltol locus, we documented new allelic pattern in selected highly tolerant and tolerant genotypes with RM8094 marker as compared to Pokkali. Besides, another marker RM10694 was found to associate with selection of salinity tolerant genotypes similar to Pokkali. In gene expression studies, no significant difference linked with abscisic acid (ABA), calciumdependent proteins kinase (CDPK), ionic and osmotic signaling pathways in salinity tolerant genotypes was found as compared to sensitive line (IR29). Induction of AP37 gene expression differentiated Kamini and Marishal genotypes from other tolerant and sensitive lines. The chlorophyll and protein contents were maintained in highly tolerant genotypes (Marishal, Kamini and Talmugra) as compared to sensitive one (IR29). Among agronomic traits, selected rice lines recorded to have significant morphological features such as plant height, tiller number, leaf length and width in order to tolerate salt stress. Genetic diversity analysis revealed that, highly tolerant genotypes showed distant relationship with Pokkali at genetic level. © 2016 Friends Science Publishers