QTL ANALYSIS OF TRICHOME-MEDIATED INSECT RESISTANCE IN POTATO

Genetic mapping of several components of a complex type of insect resi stance has been undertaken as a means toward more efficient use of the valuable characteristics of a wild relative of potato. RFLP maps cons tructed on interspecific diploid progenies of Solanum tuberosum x S. b erthaultii were used in conjunction with morphological, biochemical an d biological phenotyping to identify quantitative trait loci (QTLs) co ntributing to trichome-mediated insect resistance. By superimposing QT L data for a wide range of phenotypes including biochemical assays, co rrelative and direct screens for insect resistance, and adaptation to the target environment on the genetic maps, we have addressed the orga nization, action and interaction of genes controlling the resistance m echanism. The outcome contributes to an understanding of the associati on between component traits and between desirable and undesirable feat ures of the donor species generated in an applied breeding program. Re search is proceeding toward the development of selectable markers for the introgression and transfer of this resistance among potato gene po ols.