ARS | Publication request: FINE SCREENING POTATO GERMPLASM FOR HIGH LEAF AND LOW TUBER GLYCOALKALOIDS

Submitted to: American Journal of Potato Research
Publication Type: Abstract Only
Publication Acceptance Date: September 19, 2001
Publication Date: N/A

Technical Abstract: High concentrations of total glycoalkaloids (TGA) in potato are undesirable for humans but have a role in resistance to some insects and diseases. Since many pests eat only the above-ground parts of the plant, and humans eat only tubers, breeding for high TGA levels in leaves and low levels in tubers is an attractive goal. This strategy has been pursued using S. chacoense, a species that has leptine glycoalkaloids that are produced onl in leaves and not in tubers. When 51 populations of 10 Solanum species were tested for types and amount of glycoalkaloids, 15 populations had more in their leaves than tubers (each population was represented by a bulk of the tissue of five plants). Four populations with the highest leaf/tuber (L/T) ratio (about 4, 6, 9 and 18 fold) were selected. Twenty-seven new seedling for each of these populations were reared for individual tests. The result revealed particularly wide variation of ratios within two of the populations. For example, one extreme genotype of S. neocardenasii 50264 had 44-fold L/T difference (532/12 mg percent) and one S. vernei 458371 genotype had a 38-fold difference (2294/61 mg percent). Several glycoalkaloid classes were involved. It should be possible to select and enhance germplasm with TGA other than leptines at very high levels in leave but low levels in tubers.