Determination of novel resistant sources of chickpea genotypes under multi‑environments against Ascochyta blight using GGE biplot analysis

Chickpea (Cicer arietinum L.) is the second largest pulse crop grown worldwide. Ascochyta blight (AB), caused by Ascochyta rabiei (Pass.) Labr. is the most devastating disease of the crop in most chickpeagrowing areas worldwide. A collection of 200 Global Ascochyta Blight Reference Set in Chickpea (GABRSC), comprising advanced breeding lines and released varieties, was evaluated along with a susceptible check to AB over two consecutive years (2021-2002 and 2022-2023) under field conditions in six countries (Lebanon, Morocco, Ethiopia, India, Tunisia, and Turkey). The experiment was conducted in two replications using Alpha lattice design. Restricted Maximum Likelihood (REML) analysis revealed significant differences between genotypes (G), environments (E), and genotype x environment interactions (GEI). The results reflected the most variation attributed to E (15.1%), followed by G (59.4%), indicating that AB resistance is strongly influenced by genetics, making it a promising trait for selection in breeding. However, GEI attibuted (25.5%) indicating that the genotype performance was not consistent across all environments, however, the results identified 10 promising genotypes (S0110227, S0110088, S160454, S100115, S0110028, M-2635, S0110075, S0110211, S160483, and SE26IN) exhibiting stability with AB severity ≤4 (based on the 1–9 scale) across multiple seasons and locations. The GGE biplot analysis explained 58.38% of the total variation. These resistant genotypes would be valuable as stable donors of resistance in chickpea breeding programs aimed at developing varieties resistant to Ascochyta blight.