Molecular Characterization, Morphophysiological and Biochemical Evaluation of F2 and F3 Generation of MAS 946-1 x ADT 43 Under Aerobic Condition

Tolerance for abiotic stress is a complex trait, which is controlled by various morphological, physiological and biochemical attributes. Identifying key mechanisms involved in tolerance will help to speed up the breeding efforts to develop tolerant genotypes. A study was conducted in generations of MAS 946-1 x ADT 43 in water limiting (aerobic) condition. 166 lines of F2 and 10 selected lines of F3 generations were evaluated during dry season of year 2010 and 2011 under aerobic condition in east coast region of Tamilnadu. Tolerant lines of F2, namely L77, L21, L34, L91, L60, L19, L93, L96, L37 and L94 were identified based on grain yield, which had good spikelet fertility. The tolerant ten lines with their parents were forwarded to next generation to measure the changes in the morphophysiological traits and biochemical activities on active tillering and maturity stage. The genotypes, showed enhanced level of chlorophyll content, relative water content, membrane stability index and antioxidant enzyme activities. A total of 56 alleles were detected in 10 F3s and two parents and the number of alleles per locus ranged from 3 to 7 with an average of 3.78 per locus. Among the primers used, RM224 identified more number of alleles and average PIC was 0.658. The dendrogram based on SSR marker analysis grouped the 12 lines into six clusters, where cluster II was the largest with four lines.