Development of Groundnut (Arachis hypogaea L.) Breeding Populations for Yield and Late leaf Spot Resistance under Togo Conditions

Abstract

Aims: The development and release of high-yielding, late leaf spot (LLS)-resistant groundnut varieties have significant market potential in Togo and West Africa. This study aimed to identify suitable breeding populations for developing farmer-preferred, LLS-resistant varieties. Study Design: F2 progenies from a North Carolina II factorial mating design were evaluated across three agroecological environments in Togo using an alpha lattice design. Place and Duration of Study: F1S were produced at ICRISAT-WCA in Bamako (August–September 2019), and 16 F2 families were assessed across four agroecological zones in Togo (April–November 2021). Methodology: Eight genotypes were crossed in a factorial mating design. Genetic analysis was used to assess LLS resistance and yield-related traits of the F2 progenies. General combining ability (GCA), specific combining ability (SCA), and heritability (h²) were estimated, and correlations between traits and marker-based genetic distances were evaluated. Results: LLS resistance was mainly governed by additive gene effects (h² = 0.86–0.89), while most yield traits also showed additive variance (h² = 0.73–0.86), except pod weight.    Significant GCA correlations were observed between LLS, hundred-seed weight (r = 0.90; P = 0.008), and shelling percentage (r = 0.83; P = 0.04), indicating that a selection index approach would be effective. No correlation was found between SNP-based genetic distance and SCA. Populations derived from lines 43AH and ICG7878 exhibited the highest GCA and are promising for LLS-resistant variety development, while populations from lines 12CS22 and 12CS36 are recommended for high-yielding variety advancement. Conclusion: Additive gene effects predominate for LLS resistance and most yield traits, suggesting strong potential for genetic improvement. Specific F2 populations have been identified as promising candidates for developing farmer-preferred, high-yielding, LLS-resistant groundnut varieties in Togo.