GENETIC DIVERSITY ANALYSIS OF DEEP WATER RICE AND SCREENING OF RICE (Oryza sativa L.) GENOTYPES FOR BACTERIAL LEAF BLIGHT

Abstract

Genetic diversity analysis was performed to investigate polymorphism among deep water rice and molecular screening to identify bacterial leaf blight disease resistant gene containing rice genotypes. In the flooding region, most of the deep water rice genotypes is drown due to flood. Besides, rice genotype also affected by bacterial leaf blight disease which also causes vast yield loss. The experiment was carried out with 15 and 41 rice genotypes with five well known SSR and five gene specific markers amplification respectively. In case of 15 deep water rice, fifty nine alleles ranged from 7 to 16 alleles per locus and an average of 11.8 was detected. Forty seven polymorphic alleles were also identified. The Polymorphic Information Content (PIC) of SSR markers ranged from 0.103 (RM206) to 0.494 (RM252) with an average value of PIC 0.317. Three primers showed moderate diversity and two primers showed low diversity on the basis of PIC value. The RM252 marker can be considered as the best marker for giving highest number of band. The similarity among rice genotypes was computed from combined data for the 5 primers that ranged from 0.3729 to 0.9375 with an average of 0.7048. Dendrogram indicated the genetic distance of 15 deep water rice genotypes by grouping them into four main clusters. In case of gene specific markers Xa4, xa5, Xa7, x13 and Xa21 bacterial leaf blight disease resistant genotypes were identified carrying bacterial leaf blight resistant genes. Among 41 rice genotypes, two different genes were present in 10 genotypes (Dudhsor, Dula Bech, Dulai Aman, Kata Mukul, Anguli Aman, Katari, BR16, BR18, BRRI dhan29 and BRRI dhan58) and one separate gene was present in 12 genotypes. Phylogenetic tree represents the genetic relatedness of 41 rice genotypes by diving them into two main clusters with sub clusters. These results can be conveniently used for identifying diverse parent for the development of high qualitative and quantitative characteristics bearing genotypes in rice.