Microsatellite markers reveal genetic diversity and population genetic structure of the threatened Martaban camphor [Cinnamomum parthenoxylon (Jack) Meisn]

Abstract

Martaban camphor [Cinnamomum parthenoxylon (Jack) Meisn] is a woody tree in India, China, Indonesia, Thailand, and Vietnam and has been widely utilized for commercial purposes. It is threatened due to fragmented habitats, over-deforestation, and oil extraction. To conserve this species, the investigation of genetic diversity and population structure of this species is essential. Herein, we analyzed 192 adult trees from eight populations covering its natural distribution range in Vietnam using ten polymorphic EST-SSR markers. Medium levels of genetic diversity (R = 2.7, Ho = 0.399, He = 0.426) and genetic differences between populations (Fst = 0.223) were determined. Two populations, Cuc Phuong and Xuan Nha have undergone recent bottlenecks. These results indicated that anthropogenic activities may be the major factor for the low heterozygosity and influenced the number of alleles in all C. parthenoxylon populations. Clustering analyses revealed three genetic clusters that related to gene flow between different areas. We proposed in situ conservation for some populations with high levels of allelic richness, genetic diversity, or private alleles. The collecting of the seeds of the remaining populations for ex-situ conservation could be performed.

Keywords

• admixture
• bottleneck
• genetic variability
• human activities
• species conservation