Genotype x environment interaction and yield stability estimate of some sweet potato [Ipomoea batatas (L.)Lam] breeding lines in South Africa

Adebola, Abe Shegro, S Laurie, L Zulu, M Pillay
Genotype x environment interaction and yield stability was evaluated for root yield for 28 sweetpotato breeding lines in South Africa using the Additive Main Effects and Multiplicative Interaction (AMMI) stability parameter. Genotype x environment interactions showed the inconsistency of the performance of the breeding lines over environments and seasons. The analysis of variance showed that the genotype x environment interaction were significant for root yield. The stability parameter used in
more » ... his study identifies cultivar Monate as high yielding and stable across locations. The first two interaction principal component axes (IPCA) of the AMMI model accounted for 82.81% of the total genotype x environment interaction sum of squares for root yield. The AMMI biplot depicted the breeding lines on the bases of their adaptation patterns. Breeding lines Monate x 1999-9-4 and Khano x 1999-9-4 were found to be best adapted at Roodeplaat (A) environment while parental lines Ndou and 1999-9-4 as well as the breeding lines Monate x Khano, Khano x 1999-5-1 and 1999-9-4 x Khano were found to be the highest yielding at Fort Cox (D) environment. They were therefore recommended for cultivation in those environments. Key words: Additive main effects and multiplicative interaction (AMMI) model, breeding lines, genotype by environment interaction, stability; sweet potato.