Viruses that occur frequently in potato crops in Brazil are responsible for crop yield losses, mainly when caused by a combination of viruses. For PVY and PVX the type of resistance used is immunity, controlled by single and dominant genes. Early blight caused by Alternaria solani is one of the most important potato diseases in Brazil, especially when high air humidity and warm weather conditions prevail. This disease can cause losses up to 73%. The use of resistant varieties is an efficient control measure, being simultaneously harmless to environment and humans and providing an expressive reduction in costs. Genetic resistance has also the advantage that it can be used in association with other control methods in integrated disease management. In the potato breeding program, Embrapa Hortaliças annually evaluates the immunity to PVY and PVX, the resistance to early blight and agronomic traits. Among the clones evaluated in 1991 and 1992, 'Embrapa/CIP-PP063' and 'Embrapa/CIP-PP084' stood out with good agronomical characteristics, immunity to PVY and PVX, and high levels of resistance to early blight. Both are recommended for use as parents in breeding programs for resistance to early blight. Clones Embrapa/CIP-PP063 and Embrapa/CIP-PP084 are available for cooperative work with other institutions, as in vitro plantlets or tubers.
Solanum tuberosum; Alternaria solani; germplasm; fungus; breeding; PVY; PVX