New insights into the ecology of Phytophthora ramorum in streams

Abstract

Many Phytophthora species, including Phytophthora ramorum, have been reported from surface waters such as canals, streams, rivers, ponds, and reservoirs, often in association with infested agricultural or natural landscapes (Hong and Moorman 2005). Phytophthora species are recovered with regularity and abundance from streams and rivers, in many cases in the absence of apparent terrestrial infestations (Hwang et al. 2010, Reeser et al. 2011, Sutton et al. 2009), or under conditions not conducive to sporulation in the landscape in the case of California summers. This strongly suggests that these organisms can complete their life cycle in aquatic environments, yet the biological underpinnings of this phenomenon remain effectively unknown. What Phytophthora propagules occur in surface waters? How frequent and widespread are they in such environments? From what substrates do they originate? What is their potential to infect plant material in this environment? To address these questions, we have undertaken experiments focusing on P. ramorum in both naturally infested California streams and controlled environments. The persistence of such plant pathogens in water bodies has significant implications for their spread and management in both agricultural and more natural contexts.

Parent Publication

• Proceedings of the sudden oak death fifth science symposium

Citation

Aram, Kamyar; Rizzo, David M. 2013. New insights into the ecology of Phytophthora ramorum in streams. In: Frankel, S.J.; Kliejunas, J.T.; Palmieri, K.M.; Alexander, J.M. tech. coords. Proceedings of the sudden oak death fifth science symposium. Gen. Tech. Rep. PSW-GTR-243. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 45-47.