Genetic diversity and nutritional analysis of sweet potato [Ipomoea batatas (l.) Lam.] genotypes in Abakaliki, Nigeria

Abstract

BACKGROUND: Sweet potato is an important root crop cultivated in different countries of the world. Its production and productivity are limited by factors such as the use of unimproved local varieties, pests, disease, and drought. To overcome these constraints, diversity in sweet potato genotypes could be a prerequisite for breeding programs. The present study aimed to determine the genetic diversity and nutritional composition of sweet potato accessions. One hundred accessions of sweet potato were collected from Nigeria and Niger for agro-morphological characterization and 50 of them were used for nutritional and molecular analysis. Eleven quantitative traits, six nutritional traits, and ten SSR markers were used for diversity analysis. RESULTS: Analysis of variance (ANOVA) revealed significant differences (p < 0.01) among the sweet potato varieties for all the agro-morphological and nutritional traits studied. Accessions with orange flesh color had higher beta-carotene content compared to those with white, cream, and yellow flesh color. From the molecular diversity analysis, a total of 20 alleles were detected in 50 sweet potato accessions using 10 SSR markers. The average values for Na, Ne, I, Ho, He, and PIC were 2, 1.62, 0.55, 0.40, 0.37, and 0.30 respectively. Cluster analysis based on dissimilarity matrix grouped the accessions into two major clusters. Analysis of molecular variance (AMOVA) revealed 11% variation among the populations and 89% variation within the population, indicating low genetic variation among the populations and high genetic variation within population at p < 0.001. CONCLUSION: Overall, variability was observed among the studied sweet potato accessions based on agro-morphological, nutritional traits and the SSR markers used. This will help breeding in using these genotypes for further improvement of the studied traits.