SCREENING OF F2 POPULATIONS AND MOLECULAR CHARACTERIZATION OF UFRA RESISTANT GENOTYPES OF RICE

Abstract

The experiments were conducted in the experimental field and laboratory of Plant Pathology Division, Bangladesh Rice Research Institute (BRR!), Gazipur during 2006-2007. Thirteen F2 lines of rice were tested against ufra. Among the 1 146 plants of F2 population under 13 lines, 406 were found highly resistant, 216 moderately resistant, 157 resistant, 94 moderate susceptible, 61 susceptible and 212 highly susceptible. The highly resistant and resistant plants were selected for crossing program for the development of ufra resistant varieties. Genetic diversity was assessed by analyzing 6 SSR and 3VNTR markers for ufra resistant genotypes. All the markers were found polymorphic. Cluster analysis according to the UPGMA method illustrated the genetic relationships among the 12 ufra resistant and susceptible genotypes. These rice genotypes had been differentiated into three main clusters. To develop ufra resist.ant varieties and broaden the genetic base of nee varieties new breeding program should be initiated preferably using the parents (having greater genetic distances) BRI 1 and Aokazi, BR3 and Aokazi, Rayeda and BRJ, Rayeda and BRI l as they are expected to produce good segregants.