Heterosis, Combining Ability and Gene Action, for Yield and Yield Component Traits in Maize-Teosinte Hybrids

Abstract

Six hybrids were obtained from three male parents of teosinte and two commercial hybrids from maize as female parents, using factorial mating design in the season of 2018. In the two seasons of 2019 and 2020, the five parents and their six F1 hybrids were evaluated in Randomized Complete Block Design with three replicates. The results showed that the mean squares due to genotypes and their partitions to parents, crosses and their interactions with years; G x Y, P x Y and C x Y were highly significant for all the studied traits except stem diameter for G x Y and P x Y and silking date for C x Y. Crosses were found to be higher than parents in mean performance for most studied traits. The cross P2 x P5 exhibited positive and highly significant heterosis relative to mid-parent for number of tillers per plant (81.2%), plant height (61.6), number of leaves per plant (90.7) and total leaf chlorophyll (9.3%). This cross P2 x P5 had the best desirable SCA effects for number of tillers per plant, number of leaves per plant, green fodder yield per plant, crude protein and total digestible nutrients. The magnitudes of non-additive genetic variance were larger than their corresponding estimates of additive genetic variance with respect to all studied traits except for fifth leaf area, dry fodder yield per plant, crude protein and total digestible nutrients. The results illustrated that the heritability value in broad sense were ranged from 11.01 % for stem diameter to 97.23 % for fifth leaf area.