CHARACTER ASSOCIATION AND SELECTION INDICES IN FINGER MILLET [Eleusine coracana (L.) Gaertn.]

Name of the Author : P. SRILAKSHMI Title of the thesis : CHARACTER ASSOCIATION AND SELECTION INDICES IN FINGER MILLET [Eleusine coracana (L.) Gaertn. ] Degree to which it is submitted : Master of Science in Agriculture Faculty : Agriculture Department : Genetics and Plant Breeding Chairperson : Dr. D. RATNA BABU University : Acharya N.G. Ranga Agricultural University Year of Submission : 2013 Forty three genotypes of finger millet were studied during kharif 2012 at Agricultural College Farm, Bapatla to estimate genetic variability, heritability, character association, path coefficient analysis and to construct the best possible selection index for selection of superior genotypes. Analysis of variance revealed significant differences among the 43 genotypes for all the eleven characters studied indicating a high degree of variability in the material. Phenotypic and genotypic coefficient of variation also indicated the presence of considerable amount of variability for majority of the characters studied. The estimates of heritability and genetic advance as per cent of mean were high for the characters viz., seed calcium content, seed protein content, 1000-seed weight, finger length, productive tillers per plant, ear weight per plant and seed yield per plant. High heritability coupled with moderate genetic advance as per cent of mean was observed for days to 50% flowering and days to maturity. While moderate heritability coupled with moderate genetic advance as per cent of mean was observed for the characters viz., fingers per ear and plant height. Genotypic correlations in general are higher than phenotypic correlations indicating that the apparent associations are largely due to genetic reasons. The traits, productive tillers per plant, fingers per ear, 1000-seed weight, finger length and ear weight per plant were found to possess significant positive association with seed yield per plant at both genotypic and phenotypic levels. Further, path analysis revealed that productive tillers per plant, 1000-seed weight, fingers per ear and ear weight per plant also got high positive direct effect on seed yield per plant along with the strong significant positive association. Considering the nature and magnitude of character associations and their direct and indirect effects, it can be inferred that productive tillers per plant, 1000-seed weight, fingers per ear and ear weight per plant could serve as important traits in any selection programme for selecting high yielding genotypes in finger millet. Simultaneous selection taking all characters into consideration was carried out for all the forty three genotype of finger millet and found that IE-2884, Ratnagiri and Srichaitanya recorded higher selection index values in both the cases i.e., when the equal economic weights were assigned as well as when inverse of means are used as economic weights for calculation of selection index scores. In the process of constructing the suitable selection index for selection of superior genotypes in finger millet, maximum estimates of genetic advance over seed yield per plant was obtained when all the eleven characters under study are included in the construction of selection index. Further, addition of characters one by one in the selection index constructs resulted in increasing trend of genetic advance values. Restricted selection was carried out by restricting the selection for only ten out of eleven characters without affecting any change in the eleventh character. In all such eleven possible restriction selections the trait 1000-seed weight recorded highest estimate of genetic advance except when the same character is not considered for selection. This phenomenon was observed in both the cases i.e., when equal economic weights are used as well as when inverse of means are used as economic weights of the respective characters. It can be concluded that the best possible construct of selection index for selection of superior genotypes in finger millet should include all the eleven characters which were considered for present investigation. Further, in the process of assigning economic weights to different traits for estimation of score or selection index values to different genotype as well as in estimation of genetic advance values of different characters it was found that both the ways of assigning the weights i.e., by taking equal economic weights as well as using inverse of means of respective characters as economic weights are equally effective and resulted in similar conclusions. Similar trend was found in the case of restricted selection as well.