Revealing genetic diversity of three sections (Pharbitis, Quamoclit and Batatas) of Ipomoea genus by means of RAPD analysis.

摘要

RAPD markers have been used to develop genetic fingerprints for 12 Ipomoea species and eight lines of I. rubrocaerulea [I. tricolor]. Out of the 18 primers initially acquired, only 15 were of real use producing fingerprints suitable for analysis. Some 114 distinct bands were produced by the remaining 15 primers, resulting in a rather high mean of 7.6 bands per primer. Out of the 15 primers used, only three revealed an obvious polymorphism of the eight I. rubrocaerulea lines indicating that some of the I. rubrocaerulea lines show the same high level of polymorphism at the molecular level, as the tested Ipomoea species do. All 15 primers revealed significant polymorphism when only the species of Ipomoea genus were taken into consideration. The dendrogram constructed on the basis of computed genetic distances confirmed the affiliation of the tested Ipomoea species to the morphologically classified sections Pharbitis, Quamoclit and Batatas. The greatest genetic distance seems to be between section Batatas and the other two ornamental sections (Pharbitis and Quamoclit). Considering each section separately, the most homogeneous species structure was found in section Quamoclit while the other two sections showed a rather high heterogeneity of the comprised species. There can be concluded that RAPD analysis proved to be a valuable tool in identifying phylogenetic relationships among Ipomoea species. This kind of information could be of real help in identifying the most interfertil genitors for interspecific crosses required by breeding programmes both of I. batatas and of ornamental Ipomoea species.