International Research Fellowship Program: Towards Conservation and Sustainable Use: Genetic Diversity and Reproductive Mode of the Endangered Himalayan Fungus O. sinensis

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The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award will support a twenty-four-month research fellowship by Dr. Kathryn Bushley to work with Dr. Yijian Yao at the Institute of Microbiology in China. Ophiocordyceps sinensis (synonym: Cordyceps sinensis) is an endangered, endemic, and highly valued medicinal fungus which parasitizes species of the Himalayan ghost moth Thitarodes (synonym: Hepialus). The combination of fungus and parasitized moth, called Yartsa gunbu ("winter-worm, summer-grass") in Tibetan or dongchong xiacao in Chinese, has been harvested and used medicinally in both Chinese and Tibetan Medicine for at least three centuries. Within the last decade, however, a nearly tenfold increase in market value has led to increased harvest and overexploitation. This project addresses several fundamental gaps in scientific knowledge of the 1) systematics, 2) genetic diversity, 3) reproductive biology, and 4) ecology of O. sinensis which currently hamper efforts to assess the impacts of increased harvesting on population viability and to develop strategies for sustainable use. Multilocus sequence datasets are being used to better delimit species boundaries of O. sinensis and population genetic markers (microsatellites and SNPs) are being developed to characterize the distribution of genetic diversity both within and between subpopulations. This research will also contribute to a better understanding of the reproductive biology of O. sinensis by cloning the mating type locus to determine whether O. sinensis is homothallic (selfing) or heterothallic (outcrossing). Reproductive biology and spore dispersal in natural populations are also being investigated by estimating the outcrossing rate, evaluating random mating and rates of recombination using sequence based markers, and analyzing patterns of fine scale spatial genetic variation in four field populations located in Yunnan province, China. The scientific impacts of this project include delimiting phylogenetic species and characterizing the genetic diversity and reproductive biology of this economically important fungus. Results of this research will contribute to conservation efforts as well as expand knowledge of the ecology and spatial distribution of insect pathogenic fungi in nature which has applications towards their development as biocontrol agents in agriculture and forestry. The broader impacts of this work include advanced training and international collaboration for the postdoctoral fellow and undergraduate students, the forging of new relationships between scientific experts in Cordyceps biology from China and the U.S., and dissemination of knowledge relevant to conservation of O. sinensis to scientists and the general public in both China and the U.S. through a variety of means: 1) publication in peer reviewed journals, 2) sharing of knowledge with local harvesters intimately involved in managing the resource, and 3) hosting of an international symposium on sustainable use of O. sinensis for researchers from several Himalayan nations.