Physiological evaluation of maize (Zea mays) composites for genetic variability and path analysis

Abstract

The present investigation was conducted with eighteen genotypes in RBD during Rabi, 2017-18 at the ICR farm, AAU, Jorhat with an objective to estimate genetic variability among the composite varieties for the traits. Observations were recorded for six physiological characters. All the characters studied exhibited significant genotypic mean squares in ANOVA. The genotype Suwan (86.40g) had the highest estimate for grain yield per plant which was at par with VSM-31 (81.44g). The earliest variety recorded was VSM-35 with respect to days to 50% pollen-shed, days to 50% silk and days to 75% dry husk. The best performing composites based only on grain yield per plant were Suwan, VSM-31, C-8 and KDM-72. Estimates of both genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were the high for grain yield per plant, whole plant biomass and leaf area. High heritability coupled with high genetic advance as per cent of mean was observed for the traits grain yield per plant, whole plant biomass, leaf area, total plant nitrogen, total grain nitrogen, chlorophyll content at vegetative stage and chlorophyll content at reproductive stage indicating the preponderance of additive gene action for the traits. In such a situation, the path coefficient analysis provides an effective means of finding out direct and indirect causes and effects of association and permits a critical examination of the specific forces acting to produce a given correlation and measures the relative importance of each factor.