Genotype × environment interactions analysis for chickpea grain yield and related traits by a mixed model approach

The study of genotype × environment interaction is crucial for plant breeders to introduce new cultivar(s) with improved and stable yield performance. The productivity of chickpea crops is very low in Pakistan. It requires the selection of genotypes with optimal productivity for diverse environmental conditions. Fourteen different chickpea genotypes were assessed using the linear mixed model to evaluate genotypes across four diverse chickpea growing regions, including Attock (Punjab), Bhakkar (Punjab), Karak (Khyber Pakhtunkhwa), and Larkana during the year 2017–19. The environmental effect was pronounced and contributed significantly to variation (25.8%) in grain yield. Analysing genotype × environmental interactions at multiple locations facilitates ranking superior genotypes that excel in specific or diverse environments. Notably, the genotypes, viz., Fakhr-e-Thal and Bhakkar-2011, demonstrated superior performance in terms of overall grain yield. Utilising a multitrait stability index, Bittal-2016 and Thal-2006 exhibited the most stable genotypes across various environments and were observed suitable for diverse growing regions. While, for specific environmental conditions, genotypes, i.e., KK-1, Noor-2013 and Fakhr-e-thal, exhibited higher yields and stability. This showed their adaptability to the particular environment. The present study revealed that Larkana as the mega environment was conducive to higher yield, while Attock, Bhakkar, and Karak sites were less favorable for KK-3, DG-89, and Dasht. The BLUP outperformed the AMMI in our analysis of evaluating multi-location trials. The integration of WAASBY and MTSI indices proved useful in differentiating between high yielding genotypes and those with stable performance. These tools are essential for breeders aiming to select genotypes that will perform consistently across diverse environmental conditions.