Submitted to: Cucurbitaceae Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/17/2006
Publication Date: 9/18/2006
Citation: Lebeda, A., Widrlechner, M.P., Urban, J. 2006. Individual and Population Aspects of Interactions Between Cucurbits and Pseudoperonospora Cubensis: Pathotypes and Races. Cucurbitaceae Proceedings. p. 453-467.
Technical Abstract: This paper reviews our current state of knowledge about variation in interactions between Cucurbitaceae and Pseudoperonospora cubensis as a backdrop for the development and use of systems to characterize pathogenicity at the individual and population levels. Host-parasite specificity and interactions between cucurbits and P. cubensis exhibit significant variation on both the individual and population level. Yet, our knowledge of specific interactions between individual P. cubensis isolates and accessions of the most important genera of cultivated cucurbits (e.g. Cucumis, Cucurbita, Citrullus) remains limited. Recently, an improved differential set of 12 cucurbit accessions was developed to characterize pathogenic variability among P. cubensis isolates. That set included six genera (Benincasa, Citrullus, Cucumis, Cucurbita, Lagenaria and Luffa) and is now being used to differentiate pathotypes. Nevertheless, we have reasons to believe that these differentials are incomplete. Data on patterns of pathogenic variation are only available for a limited set of countries, but even those studies are typically based on individual isolates, not populations. Topics related to the development of new differential sets are discussed. For example, recent research in the Czech Republic demonstrated how data at the population level can help elucidate temporal and spatial pathogen distribution and dynamics, as well as to clarifying host-pathogen interactions. It is also important to consider the practical application of these data in resistance breeding and disease management. We conclude by proposing some ideas to promote research and collaboration on these topics.