ESTIMATION OF GENETIC VARIABILITY USING LINE X TESTER TECHNIC IN MAIZE AND STABILITY ANALYSIS FOR SUPERIOR HYBRIDS USING DIFFERENT STABILITY PROCEDURES

Abstract

Fifteen inbred lines were crossed to three testers of maize to estimate combining ability effects for maturity and yield traits. The produce 45 crosses, S.C. 168 and T.W.C. Giza 368 were evaluated across two years at the Farm of Faculty of Agriculture, Moshtohor, Benha University in RCBD with 3 replicates. Mean squares due to year (Y) genotypes (G), crosses (C), testers (T), inbred lines (L), line x tester (LxT) and interaction variance for C, L, T and LxT with (S) were significant (P>0.05) for most studied traits. Non- additive gene action (δ2SCA) is more pervading in determining inheritance of the most traits. The non-additive type of gene action is fluctuated by year changed more than additive. The inbred lines M. 645a (L4), M. 653 (L5), and M. 674 (L11) showed desirable ĝi for early maturity and grain yield plant-1. The crosses M.221xM.653, M.221xM.655b, M.221xM.657, M.221xM.671, M.221xM.674 and M.221xM.677 exhibited out-yielded SC 168 reached 9.96%, 11.35%, 12.53%, 8.32%, 11.80% and 4.80%, respectively across years. TWC (SC M 200xM418)xM.653 and (SC M200xM418)xM.674 showed superiority than TWC 368 being 9.11% and 3.78%, respectively.The eight superior hybrids along with SC168, SC hytech 2066, TWC 368 and TWC 352 were evaluated in 2019 year at various environments using RCBD with 3 replicates to identify suitable adapted maize hybrids. The main effects of genotypes, environments and their GxE interaction were highly significant (P<0.01). Hybrids M. 221 x M. 674, M. 221 x M. 655b, SC hytech 2066 and SC 168 were the most crosses stable phenotypically and genetically across environments.