Geographical and ecological variables of Pseudotaxus chienii populations

Pseudotaxus chienii, belonging to the monotypic genus Pseudotaxus (Taxaceae), is a relict conifer endemic to China. Its populations are usually small and patchily distributed, having a low capacity of natural regeneration. To gain a clearer understanding of how landscape variables affect the local adaptation of P. chienii, we applied EST-SSR markers in conjunction with landscape genetics methods: (1) to examine the population genetic pattern and spatial genetic structure; (2) to perform genome scan and selection scan to identify outlier loci and the associated landscape variables; and (3) to model the ecological niche under climate change. As a result, P. chienii was found to have a moderate level of genetic variation and a high level of genetic differentiation. Its populations displayed a significant positive relationship between the genetic and geographical distance (i.e., “isolation by distance” pattern) and a strong fine scale spatial genetic structure within 2 km. A putatively adap...