Occurrence of Phytophthora on Reforested Loose-Graded Spoils in Eastern Kentucky

Abstract

Abstract. 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.Additional

The influence of silvicultural treatments and site conditions on American chestnut (Castanea dentata) seedling establishment in eastern Kentucky, USA

“…Another concern, the common root rot fungus, Phytophthora cinnamomi, responsible for significant pre-blight American chestnut mortality (Crandall et al, 1945;Anagnostakis, 1995) was a likely contributor to mortality in the current study. A greenhouse trial using soils from our planting locations documented high susceptibility of pure American chestnut to P. cinnamomi, even under moderate levels of soil compaction and moisture ; soil baiting techniques combined with molecular approaches (i.e., PCR amplification with DNA sequencing) confirmed the presence of P. cinnamomi at these sites (Adank et al, 2008). Asian chestnuts (C. mollissima and C. crenata Siebold & Zucc.)…”

Evaluating the Use of Tree Shelters for Direct Seeding of Castanea on a Surface Mine in Appalachia

“…This pathogen was historically introduced to the American Southeast and was found to contribute to chestnut mortality and stress long before the more devastating introduction of chestnut blight [2]. In 2011 we performed soil baiting followed by PCR amplification and sequencing of the ITS region to determine if Phytophthora cinnamomi was contributing to seedling mortality [34]. P. cinnamomi was not detected in the mine soil; however, in a nearby (approximately 1000 m away) American chestnut experiment, P. cinnamomi was diagnosed on dead seedlings and P. cryptogea was detected in both spoil and water infiltrated from brown sandstone soil reclaimed using the FRA [34].…”

“…In 2011 we performed soil baiting followed by PCR amplification and sequencing of the ITS region to determine if Phytophthora cinnamomi was contributing to seedling mortality [34]. P. cinnamomi was not detected in the mine soil; however, in a nearby (approximately 1000 m away) American chestnut experiment, P. cinnamomi was diagnosed on dead seedlings and P. cryptogea was detected in both spoil and water infiltrated from brown sandstone soil reclaimed using the FRA [34]. Thus, while we are not confident that P. cinnamomi contributed to chestnut mortality in our study, it is likely that P. cinnamomi will colonize eventually and may contribute to mortality in the future.…”

Phytophthora cinnamomi Colonized Reclaimed Surface Mined Sites in Eastern Kentucky: Implications for the Restoration of Susceptible Species

“…FRA sites may also be unfavorable for P. cinnamomi for some time after reclamation due to high infiltration rates, low moisture retention, and relatively high temperatures associated with low shade, low organic matter, and little to no clay content [47][48][49]. P. cinnamomi was not detected in mine reforestation plots in southeastern Kentucky one and three years after reclamation [50], and was also not detected in a number of sites 3-20 years after reclamation in Ohio [46]. However, a recent chronosequence study in eastern Kentucky suggests that rates of microbial activity (assayed by dehydrogenase activity), microbial biomass C and N, litter decomposition rates, and CO 2 efflux in mined sites eight years after reclamation were similar to native forests 12 years after clear-cutting [51].…”