Conservation genetics and geographic patterns of genetic variation of the vulnerable officinal herb Fritillaria walujewii (Liliaceae)

Abstract

The Chinese herb Fritillaria walujewii Regel is an important officinal species that is vulnerable because of over-harvesting. Here, we examined the geographic pattern of genetic variation across the species entire range, to study its evolution process and give implication needed for the conservation. Nine haplotypes were detected on the basis of three chloroplast spacers. The most common haplotype was central in the haplotype network and was distributed widely from the Yili Valley to the eastern Tianshan Mountains. Genetic variation primarily occurred among populations and SAMOVA groups and the analysis of genetic structure showed a significant correlation between genetic and geographical distance. The fragmented distribution of F. walujewii in deep valleys may cause gene-flow barriers among distant populations and, along with genetic drift, has caused high genetic structure in the species. We identified Xinyuan County as the centre of diversification of F. walujewii, and speculated that populations in the eastern Tianshan Mountains were colonised from the Yili Valley. In relation to conservation management, we identified Xinyuan and Zhaosu County as having a high degree of genetic diversity and these should be the areas of the greatest focus for conservation.