Diallel Analysis of some Quantitative Traits in Eight Inbred Lines of Maize and Gge Biplot Analysis for Elite Hybrids

Abstract

An 8x8 half diallel analysis were performed at two planting dates to study the importance of types of combining ability (GCA and SCA) and its interaction with environment in F1 of maize. Planting dates (D), crosses (Cr), GCA, SCA, CrxD, GCAxD, SCAxD were significant for all traits. GCA/SCA exceeded the unity for most traits. Non-additive seemed to be more prevalent for plant, ear heights and grain yield plant-1. P8 gave significant positive () effects for all studied traits. High SCA effects were exhibited by the crosses P1xP7, P1xP8, P2xP5, P3xP4, P3xP8, P4xP7, P4xP8 and P5xP6 for grain yield plant-1 across planting dates. Superiority of P2xP5 and P3xP8 over SC Hytech 2031 reached 13.84 and 6.16%, respectively. However, useful heterotic effects relative to SC 128 mean value were 21.14 and 10.22%, for the aforementioned crosses, respectively. P1xP8, P4xP8 and P5xP6 gave positive insignificant out-yielded than check hybrids. The five superior hybrids P2xP5 (G1), P3xP8 (G2), P5xP6 (G3), P1xP8 (G4) and P4xP8 (G5) along with SC10 (G6), SC 128 (G7) and SC Hytech 2031(G8) were evaluated in 2019 season at various environments using RCBD with 3 replicates to identify environments and suitable adapted maize hybrids. Stable genotypes are ranked descending for means of grain yield as follows: G1 > G8> G2> G7. G1, G8, and G2 were above average stability while genotypes G7 showed below average stability. Thus, G1 (P2xP5) and G2 (P3xP8) are promising crosses, and it's recommended to register as new varieties with high productivity and stability across environments.