Character Association and D2 Analysis in Rice (Oryza sativa L.)

Abstract

The present research works entitled "Character Association and 0 2 Analysis in Rice (Oryza sativa L.) was undertaken to gather the informations on genetic variability, direct and indirect selection parameters, path coefficient analysis and genetic divergence for twelve characters viz., days to .panicle emergence, days to 50% flowering, plant height (em), number of productive tillers per plant, panicle length (em), number of grains per panicle, days to maturity, biological yield per plant (g), grain yield per plant (g), harvest index (%), I 000-grain weight with husk and I 000-grain weight without husk by evaluating thirty-seven diverse genotypes of rice. The experiment was carried out in Randomized Complete Block Design with three replications at Crop Research Centre, Sardar vallabhbhai Patel University of Agriculture and Technology, Meerut during Kharif 2011. The systematic observations were recorded for above mentioned 12 characters. The data were subjected to different biometrical computations as given above. The results obtained on different aspects for different traits are summarized her. ANOV A for the experiment revealed highly significant differences among the genotypes for all the characters under study. Number of grains per panicle and grain yield per plant showed high percentage of phenotypic and genotypic coe!licient of variability. Remaining characters exhibited moderate to low estimates of PCY and GCY. 1-ligh heritability estimates in broad sense, were observed for number of grains per panicle, number of productive tillers per plant, grain yield per plant, harvest index and I 000-grain weight with husk. Rest of the characters showed moderate to low estimates of heritability. High genetic advance in percent of mean was reflected by numbers of grains per panicle, grain yield per plant and harvest index. Two characters namely number of productive tillers per plant and biological yield per plant showed moderate genetic advance in percentage of mea. However, rest of the seven characters reflected low genetic advance (in percentage of mean).The characters namely grains per panicle. grain yield per plant and harvest index showed high heritability (broad sense) estimates coupled with high genetic advance. In the character association studies. grain yield showed highly significant and positive correlation with panicle length, biological yield per plant and harvest index. Other positive significant associations were noted between days to panicle emergence with days to maturity; days to 50 % flowering with days to maturity; panicle length with biologi~al yield per plant and harvest index with 1000-grain weight without husk. However, significant and negative association between plant height with number of productive tillers per plant, number of productive tillers per plant with days to maturity; numbers of productive tillers per plant with 1000-grain weight with and without husk and days to maturity with biological yield per plant. Path coefficient analysis of grain yield per plant and its contributing characters revealed that biological yield per plant had the highest positive direct effect on grain yield per plant followed by harvest index, I 000-grain weight without husk, number of productive "tillers per plant, I 000-grain weight with husk and panicle length. The direct effects of the remaining characters on grain yield were negative and low magnitude. The results of 0 2 analysis indicated the presence of high amount of genetic diversity among the genotypes studied. The range of genetic diversity was wide and significant variability was found among most of the genotypes. The clustering pattern suggested the lack of parallelism between geographical distribution and genetic diversity.