Variation in the evaluation of cis- and trans-<beta>-carotene in yellow-fleshed cassava (Manihot esculenta Cranz) varieties as a function of the storage root portion and sampling method

Abstract

Providing correct estimates of the carotenoid content of cassava varieties is very important in any cassava-breeding program for improving vitamin A intakes in sub-Saharan Africa especially among high-risk groups. The effect of different sampling methods-sampling with cork-borer(SPM1) and sampling without cork-borer (SPM2)-on cis- and trans-β-carotene in yellow-fleshed storage roots of cassava was investigated with 40 elite cassava varieties (comprises of 2 trials), grown in 2004/2005 growing season in replicated field trials (Randomized Complete Block Design) and harvested at 12 months after planting. The cis- and trans- isomers of β-carotene of the varieties of SPM1 and SPM2 was determined using HPLC. Result showed significant genotypic differences (P 0.05) in the two sampling methods and there was also positive correlation between the cis- and trans- β -carotene contents for both trials 1 and 2. This study provides information on β-carotene distribution and the appropriateness of SPM2 as an alternative and easy sampling method for carotenoid contents in yellow-fleshed cassava varieties