| Cathaya argyrophylla Chun et Kuang is an endangered conifer endemic to China and restricted to subtropical mountains of China. Although previous studies have revealed low level of genetic diversity and high genetic differentiation among populations, the population dynamics and evolutionary history of this species remain unknown, including the factors affecting the population genetic structure and its potential refugia in glaciation. In addition, an effective conservation strategy for C. argyrophylla awaits implementation based on the understanding of its genetic profile and evolutionary history. Based on sequence data from eight nuclear loci and two mitochondrial fragments, this study revealed the nucleotide diversity and population genetic structure and pollen viability of this species as well of C. argyrophylla. The demographic history and potential refugia of this species were investigated and the conservation strategy for C. argyrophylla was also discussed based on above results. The main results are summarized as follows:1. Nucleotide diversity and population genetic structureAfter a preliminary survey on 101 nuclear DNA regions, we obtained eight loci that generated a single and strong amplification. We amplified and sequenced these eight loci for 86 magagametphytes sampled from 86 individuals of 15 populations from the four regions. The average nucleotide diversity (θs=0.0022,πs=0.0027) across eight nuclear loci is significantly lower than that found for other conifers based on estimates of multiple loci. The DY region had the highest diversity (θs =0.0026;πs = 0.0028), followed by DY (θs =0.0023;πs = 0.0023) and YC (θs =0.0018;πs = 0.0017), and the BM region maintained the lowest (θs =0.0012;πs = 0.0015). Statistical significant linkage disequilibria existed in all four regions at most loci, and the intergenic LD was detected in the BM region. An AMOVA revealed significant proportion of diversity attributable to differences among regions (20.05%) and among...
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