Genetic diversity analysis of rice germplasm lines for yield attributing traits

Genetic divergence is an efficient tool for the selection of parents used in hybridization programme. In the present study, fifty three rice genotypes consisting of high yielding rice varieties/ cultures and IRRI germplasm lines were raised at Rice Research Station, Tirur during Sornavari, 2009 to identify diverse genotypes. They were evaluated for eight yield and yield attributing characters using D analysis, to study the diversity pattern among the genotypes. Based on the analysis, the genotypes were grouped into 11 clusters. Maximum number of 16 and 15 genotypes were grouped under cluster XI and I respectively, while clusters II, IV, V, VI, VIII, IX and X had only two genotypes each and clusters III and VII consisting of 3 and 5 genotypes respectively. Maximum inter cluster D value was observed between cluster I and X (32.96) followed by cluster I and IV (32.90). The greater the distance between the two clusters indicates wider the genetic diversity between genotypes. Hence, the genotypes in cluster I viz., ADT 39, ADT 43, ADT (R) 45. ASD 16, ASD 18 ASD 20, BL 17, BL 18, BL 24 CB 64110, JGL 17198, JGL 17204, JGL 17196, JGL 17187 and IR 36 had wider diversity with varieties TKM 11, TKM (R) 12 in cluster X and with IRRI germplasm lines IR 81396-B-B-164-4, IR 79913-B--362-B-3 in cluster IV and these lines may be utilized in further breeding programme for the exploitation of hybrid vigour. The intra cluster distance was maximum in cluster VII (24.62) followed by cluster XI (22.15) indicates hybridization involving genotypes within the same clusters may result in good cross combinations. Among the eight traits studied, maximum contribution was made by grain yield (50.87%) followed by days to 50 per cent flowering (15.02%), total grains per panicle (10.52%) and plant height (10.23%). Hence, grain yield, days to 50% flowering, total grains per panicle and plant height together contribute 86.62% towards total divergence. Therefore, these characters may be given importance during hybridization programme.