Vegetos

Abstract

The study was designed to evaluate salinity tolerance at panicle initiation stage and characterize the genetic diversity in a set of rice genotypes with different adaptation to saline soil using microsatellite markers (SSR markers). In evaluation for salinity tolerance the land races Nona bokra and Pokkali showed high tolerance at 6 EC dsm-1(Electrical Conductivity) level. In panicle initiation stage followed by FL 478 and CSR 36 with moderate tolerance. For diversity analysis, a total of 70 SSR primers across the 12 chromosome were used. Of these, 34 were polymorphic among the selected genotypes. The diversity analysis grouped the 13 genotypes into six clusters. Cluster I consisted of three varieties viz., ADT37, ADT 47 and TRY(R)3.

Cluster II was the biggest cluster having six varieties viz., ADT42, ADT43, AD09225, FL478, CSR10 and CSR36. Cluster III consisted of mono cluster of TNAU Rice ADT49 and Cluster IV consisted of TRY(R)2. Cluster V consisted of monocluster of Pokkali and cluster VI consist of Nonabokra which is highly salt tolerant. The maximum similarity value was 0.828 and the minimum similarity value was 0.502. The genetic distance was ranged between 0.172 to 0.489. The lower genetic distance of 0.172 was observed between FL478 and AD09225, and the higher genetic distance was observed between Nona bokra and ADT47 (0.489) followed by TRY(R)2 and Pokkali. The Polymorphism information content ranged from 0.138 to 0.705. The highest PIC value observed in RM493 (0.705) followed by RM 3412 (0.638) and RM 412(0.591). The lowest PIC value was observed in RM5933 (0.118), RM 240 (0.142) and RM 287 (0.138). Hence parental selection based on the genetic diversity is highly essential to develop a good variety. In future by utilizing the highly genetic divergent parents of ADT(R)47 and Nonabokra may help to develop high yielding salt tolerant varieties.