DETERMINING POPULATION VARIATION OF APPLE POWDERY MILDEW AT THE MOLECULAR LEVEL

To prove the existence of physiological races of Podosphaera leucotricha, 31 monoconidial isolates of the fungus representing five different locations within Europe have been established during the DARE project (Durable Apple Resistance in Europe) and characterized using phytopathological methods as well as AFLP marker analysis.
Using 54 stably reproducible AFLP markers, a dendrogram was constructed that displays the genetic variability of the different isolates that have been estab-lished.
Inoculation tests with detached leaves resulted in a test set of seven Malus genotypes which allows the differentiation of the five selected isolates by their viru-lence patterns.
This result demonstrates the existence of physiological races of Podos-phaera leucotricha. One of the main objectives within the framework of the project SMADIA (Sustainable production of apple and pear in Asia: understanding biology of scab and powdery mildew for developing integrated approaches of disease man-agement) is to analyse the population genetics of apple powdery mildew with a focal point on the Asian countries China and India.
For this task, easy-to-use molecular markers such as SSR markers are being developed for the analysis of the variability of apple powdery mildew samples collected at different locations in China and India.
Virulence testing is being conducted on the basis of the same set of apple cultivars and Malus species which was used in the DARE project.

XI Eucarpia Symposium on Fruit Breeding and Genetics

S. Lesemann, A. Urbanietz, F. Dunemann

Podosphaera leucotricha, Malus x domestica, AFLP markers, SSR analysis, genetic diversity, physiological races

https://doi.org/10.17660/ActaHortic.2004.663.29