Morphological and RAPD pattern variations in sweetpotato and its closely related species

Abstract

Morphological analysis was carried out in sweetpotato and its closely related Ipomoea species. Based on the principal component analysis of 110 accessions x 50 morphological characters, corolla size, corolla shape, sepal size, sepal color, sepal texture, plant pubescence, star shape inside of corolla tube bottom, and external nectary were recognized as key characters for taxonomical classification, and the accessions were classified into 3 groups. However, sweetpotato and the closest species, L trifida, could not be separated clearly. RAPD analysis applied to the two species did not define their differences either. These results suggested that sweetpotato and I. trifida were very closely related to each other from viewpoints of the morphological and genetical variations, and they might be considered as one taxon.