GENETIC VARIABILITY AND SELECTION PARAMETER FOR GRAIN YIELD AND ITS COMPONENTS IN MAIZE (ZEA MAYS L.)
H. C. Singh*, Parvej Alam, A. K. Srivastava, Geeta Rai and Ajay Kumar
Seventy eight genotypes of maize [12 parents + 66 F1s (derived from 12 parental diallel cross excluding reciprocals)] were evaluated for eleven attributes namely; days to tasseling, days to silking, days to maturity, plant height (cm) cob height (cm) ear length (cm), ear diameter (cm) number of grain rows per ear, number of grains per row, 1000- kernel weight (g) and grain yield per plant (g). Analysis of variance of means revealed highly significant differences for all the characters among parents and crosses. Phenotypic coefficient of variability (PCV) was higher than corresponding genotypic coefficient of variability (GCV) for all the characters except 1000 - kernel weight. The maximum phenotypic variability was estimated in grain yield per plant (16.16%) followed by rows per ear (11.38%) and 1000 - kernel weight (10.72%) and the least was observed in days to tasseling (3.27%), High broad sense heritability estimates were observed for all the characters (83.50 to 100%) except for cob diameter, ear length and grains per row for which it was moderate (70.30 to 79.10%). An advancement of 27.76g in grain yield per plant was expected from single cycle of selection at k=2.06. Comparatively, the expected gain to the tune of 23.45% was estimated for grain yield per plant followed by 1000 - kernel weight (22.06%), grain rows per ear (21.96%) cob height (16.18%) ear length (12.34%) and grains per row (12.31%). Path analysis revealed that ear diameter, number of rows per ear, days to tasseling and ear length had positive and high direct effect on grain yield per plant. The characters directly related to grain yield viz ear length ear diameter, rows per ear, grains per row and 1000 - kernel weight were significantly and positively correlated hence due emphasis be paid on these characters while making selection for grain yield.
Keywords: maize, genetic variability, selection parameter, heritability, genetic advance, correlation, path analysis.
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