Stability analysis for yield and yield contributing characters in hybrid maize (Zea mays L.)

Twenty one hybrids along with two check varieties of maize were assessed for genotype environment interaction (GEI) and stability for selection of the best hybrid maize in three different Agro-Ecological Zones (AEZ) of Bangladesh during rabi season 2014/2015. The experiment was laid out in Randomized Complete Block Design with 3 replications. The additive main effects and multiplicative interaction (AMMI) model was used to analyze the genotype-environment interaction over three locations to select the hybrids having higher yield (yld) and other potential attributes. The mean sum of square for genotypes was highly significant for the studied characters. Similarly, environmental variances were also highly significant for all characters. Variances due to genotype × environment interaction were highly significant for cob length and thousand seed weight (TSW). AMMI Component 1 showed variation for TSW. But AMMI Component 2 and G×E (Linear) revealed insignificant variation for all the characters. The highly significant effects of environment indicated high differential genotypic response across the different environments. The environments of Gazipur (Ij=-1.42**) and Barisal (Ij=-0.068) were poor but Rangpur (Ij=1.49)) was a favourable environments due to positive environmental index for tested maize hybrids. Considering the mean, bi and S2di for all the parameters, it was evident that all the genotypes showed different response of adaptability under different environmental conditions. Among the hybrids , WL4×WL5, WL1×WL3, WL2×WL3, WL1×WL4 and the check NK 40 exhibited the higher grain yield; bi~1 and S2di~0 indicated that these hybrids were stable across the environment. All the hybrids showed insignificant values for regression co-efficient and also deviation from regression except WL1×WL5. The AMMI biplot showed four grouping of genotypes having none of them, low yielding and unstable; one hybrid was low yielding but moderately stable; eight were high yielding and stable hybrids, and fourteen were high yielder but highly unstable.   Key words: Additive main effects and multiplicative interaction (AMMI) model, hybrid maize, stability analysis.