Use of AMMI Method for Estimating Genotype- Environment Interaction in Early Maturing Corn Hybrids

Estimation of genotype environment (GE) interaction is very important for plant breeders. The additive main effects and multiplicative interaction (AMMI) model is the combination of the analysis of variance (ANOVA) and principal components analysis (PCA) which calculates both additive and multiplicative effects. To estimate GE interaction by AMMI model, ten corn hybrids including nine hybrids that were the best hybrids in yield trials, and KSC301 were evaluated for two years in seven locations of Iran in a randomized complete block design with four replications. Results showed that the first four IPCAs and the fifth IPCA were significant at 1% and 5% probability levels, respectively. The first IPCA displayed 25.2% of GE interaction sum of squares and the other IPCAs 65.1% of GE interaction sum of squares. Four parameters including SIPC4, AMGE4, ASV and EV4 were calculated for stability determination of corn hybrids. ASV parameter showed positive and highly significant correlation with Wricke ecovalence (r = 0.76) and Huehn's S2 nonparametric statistics (r = 0.67). EV4, SIPC4 and ASV parameters had no correlation with each others. The highest grain yield belonged to hybrids No. 8 and No. 2 with 9705 and 9272 kgha-1 respectively. According to ASV parameter, hybrid No. 8 was determined as a stable hybrid with minimum interaction (260.274) and maximum grain yield (9705 kgha-1) and hybrid No. 3 with minimum interation (1899.58) was determined as unstable hybrid. According to obtained results for stability determination, hybrid No. 8 was selected as the most stable hybrid and ASV parameter was selected as the best stability parameter regarding its accurate results in comparison to the other AMMI parameters