RAPD MARKERS ASSOCIATED WITH SINGLE GENE TRAITS IN IPOMOEA TRIFIDA

Abstract

Ipomoea trifida (2X = 30) is purported to be the wild Ipomoea species most closely related to the commercially grown Ipomoea batatas (sweetpotato, 6X = 90). The two species can be crossed with much difficulty, but seed occur rarely. Ipomoea trifida has been shown to possess some agronomically desirable traits that are missing in sweetpotato (e.g., sweetpotato-weevil resistance). Attempts to locate morphological markers in the diploid trifida that would serve as indicators of successful crosses with sweetpotato resulted in the identification of two traits controlled by single genes: nectary color and male sterility. Both traits require flowering to identify, and flowering is often difficult to induce in Ipomoea species. An analysis of I. trifida accessions using RAPD molecular markers was undertaken. Using a segregant population resulting from crossing a green nectary, fertile plant with a yellow nectary, male, sterile plant, RAPD analysis resulted in clear markers for both the nectary color trait and the male sterility trait. These traits now can be identified in the absence of flowering plants.