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Submitted to: BARC Poster Day
Publication Type: Abstract Only Publication Acceptance Date: 2/1/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Solanum chacoense, a wild relative of the cultivated potato, contains several glycoalkaloids, including solanine, chaconine, and leptine. The foliar-specific leptine glycoalkaloids are believed to confer resistance to the Colorado Potato Beetle (CPB). Data from segregating F1 populations developed from crosses of high x nil and high x high leptine producers were consistent with control of leptine production by a single recessive gene; however, data from subsequent generations strongly suggests the presence of additional factors affecting the inheritance and expression of leptine glycoalkaloids in this population of S. chacoense. Using two bulked DNA samples composed of high- and low- percent leptine individuals from a segregating F1 population of S. chacoense, a 1500 bp random amplified polymorphic DNA (RAPD) product, UBC370-1500, was identified which is closely linked to high percent solanine+chaconine, and conversely to low percent leptine. The recombination value was 3% in the F1 progeny, indicating tight linkage to this recessive gene. UBC370-1500 mapped to the end of the short arm of potato chromosome 1, near the location of a previously mapped major QTL for solanidine. The observed distribution of the UBC370-1500 marker, in conjunction with these QTL data, suggest that hydroxylation of a common precursor to form leptinidine occurs prior to formation of the solanidine aglycone. Implications of these findings for the development of CPB-resistant potato varieties will be discussed. |
