Progeny Evaluation of Some Sweet Potato [Ipomoea batatas (L.) Lam.] Breeding Lines in South Africa

Sweet potato is one of the most important food crops in Africa. It provides vitamins, minerals, proteins and carbohydrates to human kind. It can also be used as animal feed, source of starch and for industrial purposes. Knowledge of the genetic variability existing among sweet potato cultivars is important for the efficient utilisation of the germplasm in breeding programmes. Evaluation and selection of sweet potato cultivars for high content of beta-carotene, dry matter content and yield is one of the main objectives of the sweet potato breeding programmes in South Africa. The objective of this study was to develop new sweet potato hybrids through a conventional crossing scheme, evaluate the hybrids for yield, beta-carotene and dry matter content and to identify hybrids that combine high yield, high beta-carotene with high dry matter content. Field experiments were conducted at Agricultural Research Council (ARC)-Roodeplaat Vegetable and Ornamental Plant Institute (VOPI) and Fort Cox Agricultural College experimental station, South Africa in 2009 and 2010 cropping seasons, to evaluate 28 sweet potato genotypes consisting of six parents and 22 hybrid progenies, for dry matter, beta-carotene, marketable yield and total yield. Analysis of variance for the traits evaluated showed highly significant differences (p <= 0.01) among the genotypes for all traits. This indicated that there is a wide variability among the sweet potato genotypes for the traits, which can be potentially exploited for future breeding programmes in South Africa. Hybrid progenies namely, Khano x 1999-5-1 and 1999-5-1 x W-119 combined high dry matter content, high beta-carotene content and good yield and are therefore suggested for further evaluation and possible recommendation for planting at suitable environments in South Africa.