Combining Ability of the Resistance to Late Blight (Phytophthora infestans) in Potato Landraces

In the Toralapa Center (Cochabamba, Bolivia) was realized crosses of 10 landraces potato resistant to late blight of the Bolivian germaplasm bank, under partial diallel design. The progenies in plantlets stage were transplanted in a Complete Random Block Design. The objectives of the research were to characterized and select genotypes of potato with the resistance to late blight (Phytophthora infestans) in the greenhouse and the field through the Area Under Disease Progress Curve (AUDPC). After the evaluation witch have been select 67% sensitive and 33% resistant. Was showed that the progenies of the crosses Bol 2835, Polonia, Bol 3147 and Morapapa, in the green house many families Bol 2835 x Morapapa; Polonia x Bol 1164; Bol 3147 x Bol 2718 had the better level to resistance to late blight. The parent Bol 3147, Bol 2835, Morapapa and Polonia show as a good specific combining ability (SCA). In young plant, were obtained 16% of susceptible genotypes and 84% resistant. The estimates variance of the GCA effect showed significant difference in the cultivars Bol 3147, Bol 2835, Morapapa y Polonia. These results confirm that showed in plantlets in Polonia, Bol 2835 and Bol 3738. The families 00223 (Polonia x Morapapa) and 00-224 (Polonia x Bol 1164) showed that the SCA was most important.