Heritability and genetic variance for grain yield and its component characters in single cross hybrids of maize (Zea mays L.)

Abstract

Estimates of genetic variability and heritability in selection of desirable characters could assist the plant breeder in ascertaining criteria to be used for the breeding programmes. Twelve inbred lines and 66 F1s generated by crossing these twelve genetically diverse parents in a half diallel mating design were evaluated at the two agricultural research stations of Kashmir in 2018 cropping season to estimate genetic variability, and heritability for, grain yield and its component characters. The estimates related to genetic components of variance revealed that estimates of additive component (D) significant for all the traits except for ear height and cob length, whereas the two measures of dominance component (H1 and H2) were significant for all the traits. This suggested the involvement of both these components in the inheritance of these traits, however greater magnitude of dominance component than its corresponding additive component of variance demonstrated greater role of dominance component in the inheritance of traits studied. Estimation of h2 was significant and positive for all characters. The estimate of h2/H2 was less than unity for days to maturity, number of ear plant-1 and protein percentage indicating greater proportion of recessive group of genes for these two traits and for rest of traits h2/H2 was more than unity indicating greater proportion of dominance group of gene. The genetic ratio KD/KR was greater than unity for all characters under study except for plant height, ear height, cob length and kernel rows cob-1 where it was less than unity. The narrow sense heritability was high for days to maturity and protein percentage and low for rest of traits in the present study which indicate that additive genetic variance for these traits was relatively less pronounced than non-additive and more ever suggested importance of dominance component.