Combining ability for beta-carotene and important quantitative traits in a cassava f1 population

Abstract

Cassava is ideal for biofortification due to its popularity as a root staple among populations with high vitamin A malnutrition. The crop is vegetatively propagated and retains the enhanced trait across generations. The combining ability for beta-carotene content and important yield trait was evaluated in a cassava F1 generation. Ten high beta-carotene clones from International Institute of Tropical Agriculture (IITA) were hybridized with ten local clones in a North Carolina Design II mating design. The F1 population was evaluated at the Kenya Agricultural Research Institute (KARI). A total of 125 families were evaluated, including 35 reciprocal crosses. The IITA parents had highly significant (P ≤ 0.001) General Combining Ability (GCA) for pulp colour and plant height. The GCA of the local parents was significant (P≤ 0.05) for harvest index, number of lobes (P≤ 0.05) and for plant height (P≤ 0.001). The Specific Combining Ability (SCA) was significant for harvest index and plant height at P≤ 0.05 and P≤ 0.001 respectively. Root pulp colour was influenced by both additive and non-additive genetic effects. There were also maternal effects associated with the trait. Results indicated that local cassava varieties can be improved for beta-carotene content without a decline in agronomic performance.