ESTIMATION OF GENETIC VARIANCE OF STARCH DIGESTIBILITY IN SWEET-POTATO

Two experiments that included 25 sweetpotato [Ipomoea batatas (L.) Lam] genotypes were planted in various environments across North Carolina, and an in vitro screening method was used to investigate genotypic and environmental variance and genotype x environment (G x E) interactions of starch digestibility in sweetpotato, Significant genotypic variation of starch digestibility was found in both experiments. Some clones have starch digestibility equivalent to that of corn. Variance analysis from both experiments indicated that genotypic variance was the dominant component in starch digestibility, G x E interaction only accounted for 6.8 % of the phenotypic variance in one experiment and for 5.9 % in the other one. These results suggested that starch digestibility of sweetpotato could be improved to a level as that of corn through conventional breeding.