Multienvironment performance of new orange-fleshed sweetpotato cultivars in South Africa
Agricultural Research Council (ARC)–Roodeplaat Vegetable and Ornamental Plant Institute, Pretoria, South Africa; ARC–Biometry Unit, Stellenbosch, South Africa; Dep. of Plant Sciences, Univ. Of the Free State, Bloemfontein, South Africa
Vitamin A deficiency is a serious health problem in South Africa, as in several parts of the world. One strategy to combat micronutrient deficiency is through biofortification, particularly through orange-fleshed sweetpotato [Ipomoea batatas (L.) Lam]. Previously, a shortage existed in South Africa of orange-fleshed genotypes with a combination of high dry mass, good yield, and good taste. Local cream-fleshed parents and orange-fleshed US introductions were used in the local polycross program. This study aimed at testing the agronomic performance, stability, and genetic diversity of newly developed orange-fleshed genotypes. Twelve entries, nine with orange flesh color, were evaluated at four sites for two seasons in multienvironment trials and the data was subjected to ANOVA and genotype plus genotype-by-environment interaction (GGE) biplot analysis. Simple-sequence repeat (SSR) analysis of the 12 entries was done followed by hierarchical clustering. Two of the orange-fleshed cultivars were recommended for production and plant breeders’ rights were registered for these. Cultivar Impilo produced stable, high root yield similar to the commercial control cultivar Beauregard; while the elite breeding line Purple Sunset (2001_5_2) had high yield and specific adaptability. Both displayed average dry mass and acceptable taste. The genetic analysis indicated relatedness of most new genotypes with the cream-fleshed parents used in the polycross program. The improved cultivars offer considerable yield advantage above US introductions previously recommended for combating vitamin A deficiency. © Crop Science Society of America.