Evaluation of grain yield stability and selection of bread wheat (Triticum aestivum L.) genotypes under different irrigation regimes

Abstract

Drought stress is one of the most important limiting factors for the production of crop plants in the arid and semi-arid regions of the world. Water deficiency during different developmental stages can change the values of yield components. The yield stability of wheat cultivars at different irrigation regimes is one of the important goals of breeders and agronomists. To determine which cultivar can be categorized as high yielding and stable at different irrigation regime, 10 bread wheat cultivars (C1-C10) were evaluated for grain yield under five levels of irrigation in two years. The significant genotype by environment (GE) interaction for yield confirms the differential response of cultivars to drought stress in different stages of plant development. Additive main effect and multiplicative interaction (AMMI) analysis were used to understand the GE interaction pattern. Based on AMMI parameters, genotypes C3, C6, and C7 exhibit the most stability in different moisture conditions. All three cultivars have been improved for rainfed conditions. Based on AMMI2 mega-environment analysis, Irrigation regimes were categorized into three groups. The first group contained E1 (rainfed) and E2 (interruption of irrigation at the tillering stage), the second group contained environments E3 (at booting stage) and E4 (after anthesis), and the tertiary group contained E5 (optimal irrigation). The results shown that AMMI stability statistics would be useful when static concept of stability is emphasized. But if the time of occurrence of drought stress in a given region is constant, then AMMI mega-environment analysis will be more appropriate.