GENETIC MAPPING OF SOLANUM CARIPENSE, A WILD RELATIVE OF PEPINO DULCE, TOMATO AND POTATO, AND A GENETIC RESOURCE FOR RESISTANCE TO POTATO LATE BLIGHT
A bi-parental cross progeny (CK) of Solanum caripense (crp) a diploid (2n=2x=24), self-incompatible, non-tuberizing herb occurring throughout the Andes (from Bolivia to Costa Rica) was used for the construction of a genetic framework map. Unexpectedly, low levels of polymorphism were encountered. The female parent, C, is resistant to late blight while the male parent, K, is susceptible. A set of selected AFLP, S-SAP, SSR, Resistance Gene Analog, and COS II polymorphic markers was used for generating parental maps. Both parental maps consist of 12 linkage groups. The C map is 689 cM, while the K map is 512 cM. The integrated map covers 804 cM and the average distance between adjacent markers is 4.3 cM. The late blight resistance phenotype mapped at a single position on the C parental map. More markers are being analyzed for incorporation into the map so as to define the corresponding potato/tomato chromosomal region bearing the resistance gene. The resistance to late blight detected in this accession proved to be effective against virtually all strains of the blight pathogen. Although crosses with potato and tomato are sterile, we will attempt to isolate the inherent gene(s) conferring resistance via positional cloning and to discern their function. Insight gained will then be applied to potato for genetic enhancement of blight resistance. Since crp has not been subjected to domestication, it should be a valuable genetic resource of resistance and other characteristics of economic relevance.
Nakitandwe, J., Trognitz, F.CH. and Trognitz, B.R. (2007). GENETIC MAPPING OF SOLANUM CARIPENSE, A WILD RELATIVE OF PEPINO DULCE, TOMATO AND POTATO, AND A GENETIC RESOURCE FOR RESISTANCE TO POTATO LATE BLIGHT. Acta Hortic. 745, 333-342
genetic enhancement, genetic map, Consensus Ortholog Sequence markers, late blight resistance, Phytophthora infestans, heterozygosity, reduced marker polymorphism