Genetische Diversität für die Widerstandsfähigkeit gegen Schaderreger bei Kartoffel

In order to increase the genetic diversity of common potato, Solanum tuberosum, wild diploid tuber-bearing Mexican potato species were screened for genetic variants that could be used in breeding programmes to improve the resistance of potato to diseases and pests. Genebank accessions of Solanum cardiophyllum, S. pinnatisectum and S. tarnii are extremely resistant to potato virus Y, late blight and Colorado potato beetle, and those of S. bulbocastanum and S. demissum to late blight and nematodes. Somatic hybridization by protoplast fusion or inter-specific crosses can be used to combine the genomes of these wild species with that of cultivated potato. Methods, like in situ hybridization techniques (GISH), flow cytometry, molecular markers and phytopathological analysis are used to select plant material with these important characters. Recently, breeding lines with improved resistance to pathogens and pests and acceptable agronomic traits have been developed and are being integrated into pre-breeding material in potato breeding programmes. This plant material is also of interest for fundamental research on the genetics of resistance in plants to pests and diseases.