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The genetic relationships among 192 superior, high–yielding, and disease-resistant sweetpotato [Ipomoea batatas (L.) Lam] accessions from the Ugandan germplasm collection were analyzed using 10 fluorescent labeled simple sequence repeat (SSR) markers. Relatedness among the genotypes was estimated using the Nei and Li genetic distance coefficient, cluster analysis and principle component analysis methods of NTSYS-pc software. The polymorphic information content of the SSR markers used in this study ranged from 0.23 to 0.76 for loci IB-S07 and IB-R12, respectively, with a mean value of 0.62. The number of polymorphic alleles detected per locus ranged from two to six with a mean of four, a confirmation of the effectiveness of microsatellite detection on an automated ABI 3730 sequencer. The mean pairwise genetic distance among the 192 genotypes was 0.57, an indication of moderately high genetic diversity. Cluster analysis divided the accessions into four major groups with no relationship to the district of origin. Two sets of duplicates were identified through SSR genotyping in this study. Up to 190 distinct accessions for use as potential parental genotypes in hybridization schemes for cultivar development in the region were identified.

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Additional index words. Ipomoea batatas, sweetpotato virus disease, alternaria bataticola blight, provitamin A Two sweetpotato [Ipomoea batatas L. (Lam.)] cultivars, NASPOT 12 O (Namulonge sweetpotato 12 orange-fleshed) and NASPOT 13 O (Namulonge sweetpotato 13 orange-fleshed) were approved for release by the Ugandan Plant Variety Release Committee (UPVRC) in Nov. 2013(Ssemakula et al., 2013. This brings to 22, the number of sweetpotato cultivars officially released between 1999 and 2013 by the National Sweetpotato Program in Uganda (Mwanga et al., 2011;Ssemakula et al., 2013). The two cultivars herein described and released in 2013, have high average storage root yields, 43.1 t • ha -1 ('NASPOT 12 O') and 27.8 t • ha -1 ('NASPOT 13 O') on station, and 14.9 t • ha -1 ('NASPOT 12 O') and 9.7 t • ha -1 ('NASPOT 13 O') on farm compared with the national on-farm average for Uganda of 4.5 t • ha -1 (FAOSTAT 2010;Low et al., 2009). The cultivars have acceptable root shape, high dry matter content (DMC) (>30%) with