This presentation consists of three points. The first point is that the cytogenetical study provides evidence of autoploidy of sweetpotato and the wild polyploids in the Ipomoea trifida complex. The second point concerns the feasibility of the gene flow in a circulationg system among sweet potato and its wild relatives. The thrid point relates to the degrees of heterozygosity of the resynthesized hexaploids byThis presentation consists of three points. The first point is that the cytogenetical study provides evidence of autoploidy of sweet potato and the wild polyploids in the Ipomoea trifida complex. The second point concerns the feasibility of the gene flow in a circulating system among sweet potato and its wild relatives. The third point relates to the degrees of heterozygosity of the resynthesized hexaploids by unreduced gametes of triploids. unreduced gametes of triploids.