Genetic divergence studies for drought tolerance in rice (Oryza sativa L.) using morphological traits and molecular markers

摘要

Assessing diversity is a prerequisite for any crop improvement programme. In the present investigation, genetic divergence was estimated by employing Mahalanobis'D2-statistics and molecular markers (SSR) to examine diverse rice landraces. Analysis ofvariance revealed the highly significant differences among the landraces for all the characters under study. Based on the inter-se genetic distance, 20 rice landraces were grouped into five clusters. Clustering pattern indicated that 13 out of 20 belongto cluster I. On the other hand, four genotypes belongs to cluster II and cluster III, IV, V consists of one genotype each. To access the molecular diversity among 20 rice landraces, 16 random SSR markers were used out of which, 10 were found polymorphic. A total of 33 alleles were detected by 10 polymorphic markers across 20 rice landraces with an average of 3.3 alleles per polymorphic marker. PIC value ranged from 0.345 to 0.775 and marker RM152 was found to be the most appropriate marker to discriminate among the rice genotypes owing to the highest PIC value of 0.775. On the basis of dendrogram, the highest similarity observed between cultivar Ekha Keha and B-6149FMR-7 and most diverse cultivar was Swarna and Xinuozao.