Genetic improvement of beta carotene in cassava (Manihot esculenta Crantz) landraces

The aim of this study was to identify farmers’ adoption challenges, perceptions and preferences of yellow-flesh cassava. Combining ability and stability of these genotypes were also determined. Total carotenoid content (TCC), proximate values and hydrogen cyanide (HCN) of the yellow-flesh cassava were measured and the retention of carotenoids in boiled biofortified cassava was determined. This information will help breeders to identify genotypes with the best nutritional quality across the tested locations for planting and promotion in Ghana also could provide a basis for implementing a recurrent selection scheme for developing cassava varieties with high levels of carotenoids and dry matter. In all the locations visited, farmers’ knowledge on the improved cassava varieties (white flesh) and the yellow-flesh cassava were generally poor among the men and women interviewed, due to their inability to access planting materials, which could be improved by strengthening the cassava seed system for awareness, and increased availability of the varieties to farmers. Very few men and women cultivated improved varieties and yellow-flesh cassava. The young adults, who are the future of the agricultural sector, lacked access to improved varieties and they must be given extra attention to understand the activities of cassava breeding programmes, to empower them to make use of these materials. The general combining ability (GCA) was larger than specific combining ability (SCA) for cassava mosaic disease (CMD), harvest index (HI) and TCC, with predictability ratios (0.98, 0.88 and 0.92 respectively) close to one. Hence, there is a possibility for improvement of the characteristics by selection. Positive significant correlation between pulp colour and TCC (r=0.59) and pulp colour and cortex colour (r=0.58) were observed. Negative significant correlation were seen between CGM and HI (r=-0.50), CMD and RTN (r=-0.45), and HI and RTN (r=-0.51). It implies that these key traits could be