GENETIC DIVERGENCE STUDIES FOR YIELD COMPONENTS AND GRAIN QUALITY PARAMETERS IN RICE (Oryza sativa L.)
Loading...
Files
Date
2015
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Acharya N.G. Ranga Agricultural University, Guntur
Abstract
The present investigation was carried out during kharif, 2014 at Agricultural College Farm, Bapatla, with 64 genotypes of Rice (Oryza sativa L.) to elicit information on the nature and extent of variability, heritability, genetic advance, character association, the magnitude of direct and indirect effects of yield components on yield and genetic divergence based on the characters viz., days to 50% flowering, days to maturity, plant height, number of productive tillers per plant, panicle length, number of total grains per panicle, test weight, grain yield per plant, hulling percentage, milling percentage, head rice recovery percentage, L/B ratio, water uptake, kernel elongation ratio, volume expansion ratio, amylose content and protein percentage.
The analysis of variance revealed significant differences among the genotypes for all the characters studied indicating that the data generated from the above diverse material shall represent wide variability. The genotypic coefficients of variation for all the characters studied were lesser than the phenotypic coefficients of variation indicating the modifying effect of the environment in association with the characters at genotypic level. The genetic parameters revealed that moderate to high variability and high heritability coupled with high genetic advance as per cent of mean were observed for grain yield per plant (g), panicle length (cm), number of grains per panicle, head rice recovery per cent, volume expansion ratio, L/B ratio and protein per cent suggesting the predominance of additive type of gene action in controlling these traits with less influenced by the environment. These results indicating the operation of additive gene action in the inheritance of these traits and improvement of these characters is possible through direct phenotypic simple selection.
The correlation studies revealed that the traits viz., number of productive tillers per plant, number of total grains per panicle, test weight and milling percentage had significant positive association with grain yield at both phenotypic and genotypic levels. So, advancement in grain yield is possible by giving emphasis on these characters in selection scheme.
Path coefficient analysis revealed that the characters plant height, number of productive tillers per plant, panicle length, number of grains per panicle, test weight and days to maturity showed positive direct effect and positive correlation with grain yield per plant.
The results of D2 analysis indicated the presence of considerable genetic divergence among the 64 genotypes studied. The 64 genotypes are grouped into nine clusters. Out of 17 characters studied, head rice recovery, test weight, volume expansion ratio, milling percentage, number of grains per panicle and protein per cent contributed maximum towards divergence. Based upon the divergence studies crosses may be made between the genotypes of clusters VII (RNR 17472) and VIII (BPT 2658) followed by genotypes of clusters IV (CN 1443-5-2-5) and IX (OR 2545-11) to obtain desirable transgressive recombinants for yield and quality traits.
The principal component analysis identified eight principal components and PC 1 contributed maximum towards the total variance. Genotypes like RP5893-136-69-17-8-7-1, NLR 3130, CR 3605-4-2-1-2-1, BPT 2270, RNR 17472, CN 1443-5-2-5, CR 3813-4-4-4-3-1-2 and OR 2555-5 scattered distantly in 2D and 3D plots showing their maximum divergence and these genotypes can be utilized in breeding programmes for exploitation of heterosis.
Description
D5188
Keywords
null