Genotype × Environment Interactions in Sorghum Interspecific Derivatives Using Tertiary Gene Pool

ABSTRACT Sorghum wild species from the tertiary gene pool were used to diversify the genetic base by overcoming the problem of pollen‐pistil inhibitions with floral treatments. Though the immediate progeny were weak with poor seed set, a single backcross and repeated selection cycles helped in developing 13 uniform derivatives. These advanced interspecific derivatives from the crosses of cultivated sorghum, Sorghum bicolor , with wild species of the tertiary gene pool, S. versicolor and S. usumberense , were evaluated for yield traits under multilocation trials involving five locations over 2 years in a randomized complete block design replicated twice. Yield data were analysed using genotype and genotype × environment (GGE) biplot to understand stability and adoption of genotypes and multitrait selection index (MTSI). Combined analysis of variance showed that all the traits were significantly ( p < 0.05) affected by environments (E), genotypes (G), and genotype‐environment interaction (GEI). GGE identified the interspecific genotype, ISC 812–3 (25.28 g/plant grain yield) to be ideal with better grain yield and stability, while ISC 812–3 and ISC 320–5 were selected for their high and stable performance for multiple traits using the multitrait selection index (MTSI). While the primary and secondary gene pools are the foundation of traditional sorghum breeding, the tertiary gene pool is increasingly critical for overcoming modern agricultural bottlenecks where the primary advantage lies in providing untapped genetic diversity that is biologically isolated from cultivated species. Interspecific crosses have the potential to diversify the genetic base of the cultivated species, S. bicolor , which may eventually help in breaking the existing yield plateau.