Adaptability and Stability of Grain Yield Maize (Zea mays) Hybrids by Using Genotype Pattern Analysis Method (AMMI)

To study Genotype × Environment (GE) interaction, assess and determine the general and specific adaptation of grain yield in maize hybrids, AMMI (Additive Main effect and Multiplicative Interaction) method was employed. Twelve late and mid mature maize hybrids were evaluated in 24 environmental conditions, namely (2 years × 12 locations). The experiment was conducted in 2003 and 2004 in RCB design of 4 replications in all the locations. According to simple and combined ANOVA results, differences among genotypes were significant. AMMI analysis revealed that treatment, model, genotype, environment and GEI had highly significant effects on the first four components in total expressing more than 80% of GEI sum of squares. According to AMMI analysis SC 76 with the lowest IPC1 was determined as the most stable hybrid. AMMI 4 parameters (SIPC 4, EV 4 and AMGE 4) confirmed the above results. Also, pattern analysis on basis of the first two components of the model distinguished SC 76 as the most stable for either release or being used in breeding programs. So, according to the obtained results SC 725 and 726 with 11.93 and 11.84 tha-1 of grain yield respectively as well as stable performance in all environments were determined as the desired varieties.