Genetic diversity and genetic structure of wild Pinellia ternata (Araceae) in China

Abstract

Due to global climate change (especially the repeated fluctuation of the Quaternary climate) and environmental isolation have a profound impact on the genetic diversity, genetic structure, geographical distribution pattern and population historical dynamics of modern plants. We used the research method of molecular pedigree geography to analyze the three non-coding chloroplast fragments psbK-psbI, atpF-atpH and trnL-F of 212 individuals from 19 populations in China of Pinellia ternata, a Araceae Pinellia perennial herb with high value of medicin, to explore the genetic diversity, genetic structure, geographical distribution pattern and its causes, and also explore the historical dynamics of its population. The results were as follows: (1) The total haplotype diversity (Hd) of P. ternata was 0.882 and the total nucleotide diversity (π) was 1.23 × 10-3, which means high genetic diversity at the species level. (2) The results of molecular analysis of variance (AMOVA) showed that genetic variation of P. ternata occurred mainly in 89.27% of populations, with significant genetic differentiation (FST=0.909, P GST(0.01<P<0.05) indicated that the chloroplast haplotypes had obvious molecular lineage and geographical structure. (3) The central test results showed that Tajima’s D value, Fu and Li's D value and Fu and Li's F* value were insignificantly positive value. Fu's Fs value was insignificantly negative value. And the mismatch analysis curve showed double peaks, indicating that the P. ternata populations had not experienced expansion events. (4) The geographical distribution of haplotype showed that the southwest and central eastern regions were characterized by higher haplotype diversity, and there were unique haplotype. For this reason, it is speculated that there were ice age shelters in these two regions during the Quaternary ice age. In a word, through the analysis of three chloroplast genes of P. ternata in different regions, we have clarified its genetic diversity, genetic structure and geographical distribution pattern. In addition, we have put forward scientific suggestions and protection strategies for molecular screening and protection of excellent provenances of P. ternata.

Keywords

• pinellia ternata
• geographical distribution pattern
• genetic diversity
• genetic structure
• glacial refugia