Occurrence of phytophthora on reforested loose-graded spoils in Eastern Kentucky

Plant pathogens of the genus Phytophthora may pose a threat to trees on reclaimed mine lands. The presence of these pathogens in forest soils of Appalachia has been documented, but their presence and relative distribution in mine spoils is unknown. Soil samples from mine spoils at the Bent Mountain, KY reforestation site were tested for presence of Phytophthora spp., and, specifically, P. cinnamomi, using a soil-baiting method. Loose-graded mine spoils (brown sandstone, gray sandstone, mixed spoil, and shale) dumped in 2005 and 2007 at the Bent Mountain reforestation site were tested monthly from May to October 2007 for Phytophthora at the surface (top 0-10 cm) using a soil baiting method. Soils collected from two non-mined control sites within Robinson Forest and Berea Forest were also tested using the same method. Colonies obtained from the baiting method were isolated in PARP-H V8 Phytophthora-selective medium and incubated at 25°C. Colonies with Phytophthora-characteristic morphology were tested by PCR. PCR results, confirmed by DNA sequencing, indicate that P. cinnamomi was successfully isolated using the baiting method from forest soils. No Phytophthora spp. were detected by the baiting method from mine spoils. Future work will involve testing water that has infiltrated through mine spoils for presence of Phytophthora spp. Water collected from lysimeters will be filtered to capture mycelial fragments or reproductive structures of Phytophthora species through exclusion on the filter membrane and the membrane will be subjected to DNA extraction and PCR. The presence of Phytophthora spp. in spoils and water in comparison to media physiochemical characteristics, aqueous geochemistry of infiltrated waters, and tree growth with regards to reforestation efforts on different tailing media will be evaluated.