Genotype‐By‐Environment Interaction and Mega‐Environment Delineation for Cured Leaf Yield Stability in Flue‐Cured Tobacco ( Nicotiana tabacum L.) Recombinant Inbred Lines Using GGE Biplot Analysis

Tobacco, being a major cash crop, drives significant economic activity and provides job opportunities in many parts of the world. However, the presence of crossover interactions as a result of erratic environments remains a major hurdle in selection and cultivar release. Over 3 years, from 2012/2013 to 2014/2015, a set of 100 recombinant inbred lines (RILs) of flue‐cured Virginia (FCV) tobacco was evaluated. The lines, developed from four F4 populations, were tested along with three check cultivars at two sites: District Mardan, representing the plain area, and District Mansehra, representing the hilly area. Experimental units were tested under an alpha lattice design, with each entry replicated three times across all locations. Principal components 1 and 2 cumulatively explained 46.54% of phenotypic variation in yield. Based on GGE biplot analysis, genotypes G95 and G99 were recognized as stable and high‐yielding, whereas G67, G10, and G32 showed unstable performance. Generally, the performance of FCV RILs at Mansehra was more inconsistent than at Mardan, resulting in crossover interaction. Mardan in 2012/2013 and 2013/2014, along with Mansehra in 2014/15, were classified as a single mega‐environment (E‐1, E‐3, and E‐6), whereas the remaining environments were considered distinct. However, Mansehra during 2013/14 (E‐4) was characterized as an ideal environment. Similarly, G95 as well as G99 were declared ideal genotypes, i.e., both superseding the check cultivars in terms of higher yield and stability. The identified FCV lines serve as useful genetic resources for future tobacco breeding and may be released to farmers of Khyber Pakhtunkhwa province or similar environments for commercialization.