Genetic Assessment for Drought Stress in Medium Maturing Hybrids of Maize Zea mays L

Abstract

newline The immediate investigation was performed to decipher different levels of heterosis, combining ability effects, genotype × environment interaction, per se performance and phenotypic stability in maize hybrids subjected to drought stress during spring season. A set of 15 inbred lines and 3 narrow-base testers were taken to generate 45 single crosses by adopting line × tester fashion of mating during rabi 2019-20. The 45 single cross hybrids and 18 parents together with 3 commercial checks were tested in three environments, i.e. E1 (optimal irrigation), E2 (drought stress at tasseling stage, for 20 days) and E3 (drought stress at grain filling stage, for 20 days), following Randomized Complete Block Design replicated three times, during spring 2021 at Instructional Farm, Rajasthan College of Agriculture, MPUAT, Udaipur (Rajasthan). Observations were recorded on seventeen different characters. The analysis of variance demonstrated that all the genotypes were significantly different from each-other regarding all the characters, pointing towards presence of ample of genetic variation. The mean sum of squares due to genotypes, parents, crosses and parents v/s crosses were noted significant for all the characters. The survey of per se performance indicated that, in general, the genotypes performed better referring grain yield and its attributing traits in the normal environment with optimal irrigation (E1) as compared to the drought stressed environments (E2 and E3). The analyzed data referring economic heterosis for grain yield per plant, demonstrated that 4 hybrids viz., EI-2448-1 × EI-2156, EI-2448 × EI-2156, EI-2188-2 newline× EI-670-2 and EI-2188-2 × EI-586-2 in E1 displayed positive significant economic heterosis over the best check Pratap QPM Hybrid-1, and unfortunately, none of the hybrids revealed positive significant economic heterosis in E2 and E3 environments, and in pooled analysis. However, the hybrid EI-2448-1 × EI-2156 followed by EI- 2448-1 × EI-670-2 expressed significant maximum positive relati