Characterization of the genetic diversity of Uganda’s sweet potato (Ipomoea batatas) germplasm using microsatellites markers

Abstract

Knowledge about the genetic diversity and structure of crop cultivars can help make better conservation decisions, and guide crop improvement efforts. Diversity analysis using microsatellite markers was performed to assess the level of genetic diversity in sweet potato in Uganda, and evaluate the genetic relationship between the Uganda’s germplasm and some genotypes obtained from Kenya, Tanzania, Ghana, Brazil and Peru. A total of 260 sweet potato cultivars were characterized using 93 microsatellite loci. The Ugandan collection showed a large number of distinct landraces, and very low (3 %) levels of genetic diversity between genotypes obtained from the different agro-ecological zones. There was low (6 %) levels of genetic diversity observed between the East African genotypes; however unique alleles were present in collections from the various sources. Pairwise comparisons of genetic differentiation indicated that Uganda’s germplasm was significantly different (P < 0.001) from cultivars from Tanzania, Ghana, Brazil and Peru. The presence of unique alleles in populations from various Uganda’s agro-ecological zones and other global regions, as well as the regional diversity patterns, suggest that efforts should be made to further collect and characterize the germplasm in more depth.