Orchid mycorrhizal fungi associated with Platanthera cooperi

Orchid mycorrhizal associations are inseparable part of an orchid life cycle, yet weknow little about whether or how these associations and abundances of orchid mycorrhizal fungus (OMF) in soil affect their populations. Given the positive relationship of soil OMF abundance with orchid seed germination and plant emergence at local scale, it is likely that OMF abundances in roots and soil can influence the population size as well. To study the association of root and soil OMF abundances with orchid population size, we surveyed two large (>300-4000 individuals) and four small (10-30 individuals) populations of Platanthera cooperi spanning its natural distribution in the California Floristic Province across three years. Amplicons of the ITS2 region of nrDNA from P. cooperi roots and from habitat soil were subjected to high-throughput sequencing.