Estimation of Heterosis and Combining Ability for Yield, Yield Component Using Line × Tester Methods in Maize (Zea Mays L.)

Abstract

This study was initiated with the objective of estimating heterosis, combing ability of selected conventional maize genotypes, comparison between hybrids, parents, and testers. Ten maize genotypes were selected (three testers and seven lines). The crosses were done in a Line × Tester mating design to produce 21 F1 single spring hybrids during 2018. The experiment was conducted. At fall season 2019; thirty-one genotypes (21 crosses + 3 tester + 7 lines) were sown in Randomized Complete Block design (RCBD) with three replications at Gerdarash research station/College of Agricultural Engineering Sciences, Salahaddin University, Erbil. The analysis of variance confirmed that the mean squares due to genotypes were highly significant for all studied characters, the tester parent (Talar) showed maximum value for tasseling number, while the parent Mst4279 recorded the maximum value for no. of days to 50% tasseling and silking and no. of ears/plant. The hybrid 232Dss × Talar showed maximum positive heterosis for plant height and ear length. The general combining ability variance was higher than specific combining ability for the plant height, ear height, 300 grain weight (g) and tassel branch number. These characters were identified to be under the control of additive-gene. Generally, the superior maize F1 hybrid L1×T2 is recommended to be taken to large-scale multilocational trials prior to commercial cultivation in Kurdistan region.