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Abstract
Nurseries in the southeastern United States that received ornamental plants in 2004 colonized by
Phytophthora ramorum and the surrounding urban areas are being monitored to determine if this pathogen has escaped and become established. At the same time, the prevalence and diversity of other species of
Phytophthora are being investigated. Water and field soil were collected from six retail nurseries in Florida in February and March 2006 and from three retail nurseries in South Carolina in both spring and fall 2006. Water samples (1 to 2 liter) were collected from streams, retention basins, and irrigation ponds; samples of field soil (1 to 2 liter) were collected from areas where diseased plants previously had been located. In addition, 20 suburban streams draining urban landscapes in South Carolina, where infested or infected plants may have been planted, also were monitored. Streams fed by multiple feeder creeks and that drained arge landscape areas were selected for monitoring. Three to seven streams were sampled in each of five cities (Seneca, Greenville, Spartanburg, Columbia, and Aiken) in the central to northern part of South Carolina. A 1- to 2-liter sample of water was collected from each stream in spring and fall 2006. Water samples from nurseries and suburban streams were held in a cool ice chest and processed within 10 to 14 hours after collection. For each water sample, eight subsamples (50 to 200 ml, depending on water quality) were pulled through 47 mm-diameter membrane filters (Nuclepore with 3 μm pores or Durapore with 5 μm pores) by vacuum to trap propagules of
Phytophthora spp. Filters then were inverted onto PARPH-V8 selective medium to recover isolates of
Phytophthora spp. Colonies of Phytophthora spp. were counted and representative isolates were sub-cultured and stored at 15°C in the dark. For each nursery soil sample, three 100-ml subsamples were flooded with 200 ml of distilled water and camellia and rhododendron leaf pieces were floated on the water surface for 3 days at 20°C in the dark. Leaf pieces then were embedded in PARPH-V8 selective medium, and plates were placed in the dark at 20°C for 7 to 10 days to isolate
Phytophthora spp. Representative colonies were subcultured and stored as mentioned above. GPS coordinates were recorded at each soil and water sample site, and water temperature and pH were measured at each water site.
Parent Publication
Citation
Wamishe, Yeshi A.; Jeffers, Steven N.; Hwang, Jaesoon. 2008. Monitoring for
Phytophthora ramorum and other species of
Phytophthora in nurseries and urban areas in the Southeastern USA. In: Frankel, Susan J.; Kliejunas, John T.; Palmieri, Katharine M., tech. coords. 2008. Proceedings of the sudden oak death third science symposium. Gen. Tech. Rep. PSW-GTR-214. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. pp. 109-110
