Patterns of virulence diversity in Puccinia recondita on wheat in Morocco in 2005 and 2006

Abstract

A total of 105 isolates of Puccinia recondita from durum wheat and common wheat were collected from the four main agro-ecological areas of Morocco, Abda-Doukkala, Chaouia-Tadla, Gharb-Saïss and Tangérois. The isolates were tested for virulence phenotypes on seedling plants of 21 near-isogenic lines of Thatcher wheat. Eightynine virulence phenotypes were identified and the resistance genes Lr2a, Lr2b, Lr2c, Lr3bg, Lr3ka, Lr9, Lr21, and Lr24 were found to confer a good resistance on isolates of all four collections. In the set of differentials used in this study, no significant difference was found between virulence frequencies of isolates from durum and from common wheat. Principal coordinates analysis and the Kosman distance between virulence phenotypes showed that the collections from Gharb-Saïss and Tangérois were closely related to each other, while Abda-Doukkala was closely related to Chaouia-Tadla.