Late blight resistance of wild potato species under field conditions in the Northwest of Russia

• Main Author: N. M. Zoteyeva
• Format: Article
• Language: English
• Published: N.I. Vavilov All-Russian Institute of Plant Genetic Resources 2020-01-01
• Series: Труды по прикладной ботанике, генетике и селекции
• Subjects: solanum spp.; natural infection; foliar resistance; phytophthora infestans
• Online Access: https://elpub.vir.nw.ru/jour/article/view/471

Background. Despite the great efforts made by breeders, late blight remains a paramount cause of significant potato harvest losses. Introgression of various resistance genes from wild Solanum L. species is the main method to increase the resistance in potato cultivars. Field resistance is considered to be more durable than those induced by the action of single R genes. To this end, resistance sources should be selected from а wide range of species under severe natural infection.Material and methods. As the material for evaluation, 1141 accessions of 99 wild potato species belonging to 15 taxonomic series according to the system of J. Hawkes were used. Each accession was assessed for 3–5 years. A 1–9 point scale was employed to score the damage of plants every week starting from the first symptoms of the disease, where 9 meant the absence of any symptoms, and 1 the entirely damaged plant. The plants scoring 6 to 9 points were considered resistant.Results and conclusions. As a result of the long-term field observations, wild potato species, represented in the current evaluation by numerous accessions, were characterized for foliar resistance to late blight; individual introductions resistant to late blight were also identified. Some of those studied in the 1980s showed high resistance in the end of the 1990s through the 2000s. The highest percentage of resistant accessions/species was identified among the species with areas of distribution in Mexico. A group of Central American species and large part of species with areas of distribution in South America expressed high level of interspecific polymorphism in foliar resistance to late blight.