Vol. 7, Issue 1 (2019)
Genetic divergence and association study for grain yield in rice (Oryza sativa L.) genotypes
Author(s): Saba Mir, M Ashraf Bhat, Dipeeka Pandita, Haleema Ashraf, Niyaz A Dar and M Younus Wani
Abstract: The present investigation was undertaken to obtain information on the variability and genetic divergence of the genotypes studied. Assessment of genetic diversity in crop germplasm is vital for identification of the genotypes to be used in the future breeding programme. Nature and magnitude of genetic variability, genetic diversity (D2 statistics) at the phenotypic level was estimated in 102 rice genotypes. Morphological traits vis-a-vis, flag leaf angle, panicle type, awing, panicle threshability and seed coat colour was characterized using standard procedure of IRRI on the basis of scale (scores 0-9). Analysis of variance revealed significant differences among genotypes for all the traits studied. The highest phenotypic and genotypic coefficients of variability were observed for leaf width (cm)followed by tillering ability, grain yield ha-1 (q), plant height (cm), leaf length (cm) and panicle length (cm). In general the phenotypic coefficients of variation were higher than genotypic coefficients of variation which indicates the role of environment in the expression of traits under observation. The estimates of heritability in broad sense was high for all the characters. The present investigation indicates a great scope in the improvement of these traits as these characters in general possessed high estimates of heritability coupled with high genetic advancement except for days to maturity, grain length (mm) and days to 50% flowering(high heritability but moderate genetic gain) indicating the preponderance of additive gene action for control of these traits. Estimates of divergence among 102 rice genotypes revealed that significant divergence existed among them. The genotypes under study were grouped into 8 clusters as per Mahalanobis D2 (1928) analysis employing Tochers method; with maximum number of genotypes in cluster IV (40) followed by cluster II (23), cluster VII (16), cluster VI (14) and cluster VIII (3). Maximum intercluster distance was observed between cluster VII and VIII (1146.52) while maximum intracluster distance was observed in cluster V (1271.69).The per cent contribution towards the total genetic divergence revealed that plant height (cm), days to 50% flowering, grain yield ha-1 (q), days to maturity, tillering ability and leaf width (cm)were the main contributing characters towards total genetic divergence.
Pages: 1504-1511 | 346 Views 66 Downloads
download (8300KB)
How to cite this article:
Saba Mir, M Ashraf Bhat, Dipeeka Pandita, Haleema Ashraf, Niyaz A Dar, M Younus Wani. Genetic divergence and association study for grain yield in rice (Oryza sativa L.) genotypes. Int J Chem Stud 2019;7(1):1504-1511.
