<i>Venturia inaequalis</i>Resistance in Apple

Abstract

Abstract Apple scab caused by Venturia inaequalis has evoked the interest for quite different reasons of scientists, agronomists, producers and consumers since over a century. Consumers select spotless apples, producers want to avoid damage, agronomists are asked to develop and implement control measures mostly based on fungicides, scientists are challenged to find cheaper and less questioned control measures. Under these premises a high number of publications have appeared dealing with almost all aspects of the interaction V. inaequalis-Malus. This review considers the advances of the past 10 years due to new genetic tools. It tries to reevaluate and value earlier works. The complex genetic of scab resistance in Malus is viewed in the context of single resistance genes, QTLs and functional interactions at molecular level. Consequences for breeding and for the creation of genetically modified apples are discussed. ACKNOWLEDGEMENTS We would like to thank Dr. M. Kellerhals, Agroscope, Changins-Wädenswil, Switzerland and Dr. C.E. Durel, INRA-Angers, France, for providing some of the pictures of Figure 1. Notes a The differential hosts for race 2 and 6 in CitationBus et al. (2005b) were TSR34T15 and Prima. b n.a. = data not available. ∗M = Monogenic; P = Polygenic. a Resistance gene allelic to Vf determined by progeny tests. b Data not available.