Submitted to: Journal of Heredity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 15, 1998
Publication Date: N/A
Interpretive Summary: Cultivated potato is susceptible to the Colorado potato beetle (CPB). Chemical control is available, however, natural plant resistance is preferable because of the cost of and potential for environmental damage from pesticides. Certain plants of Solanum chacoense, a wild species related to the cultivated potato, produce the foliar leptine glycoalkaloids that have been implicated as resistance factors to CPB. Recent research has suggested that it may be possible to transfer the gene(s) for foliar leptine synthesis from S. chacoense into cultivated potato. Traditionally, a breeding program with the goal of transferring a gene between species would take several years and require large amounts of plant material. Recently, techniques have become available with which we can identify molecular "markers" on the plant's DNA. We have technologies to find markers associated with leptine production in S. chacoense. One marker was found which was associated with low or nil leptine production. This can be used to follow transfer of a gene controlling leptine production from S. chacoense to cultivated potato. This will be beneficial to potato breeders and ultimately to growers by increasing efficiency in selection programs.
Using two bulked DNA samples composed of high- and low-percent leptine individuals from a segregating F1 population, a 1500 bp random amplified polymorphic DNA (RAPD) product which is closely linked to low leptine production has been identified in Solanum chacoense. The recombination value is 3% in the F1 progeny. In 16 families derived from various F1 intercross and backcross combinations, recombination values ranged from 0 - 31.2%. Partial sequence analysis confirms a close homology between UBC370 in S. chacoense and two comigrating bands in S. tuberosum 'Kennebec'. The use of such a marker in a breeding program will facilitate the development of CPB resistant potato varieties.