Genetic Diversity And Phylogeography In The National Class ? Protection Plant Of Handeliodendron Bodinieri

Handeliodendron bodinieri(Levl.)Rehd(Sapindaceae),a Chinese endemic plant species,is a Tertiary relict plant belonging to the genus of H.dendron which includes only one species.In this study,microsatellite SSR markers were used to assess the genetic diversity of H.bodinieri.The phylogeography of 8 natural populations of H.bodinieri based on the sequences variations of chloroplast DNA fragments and ITS were also investigated.The results provide a scientific basis to develop valid strategies for the protection of H.bodinieri.The main conclusions are as follows:Genetic diversity of H.bodinieri was studied using 9 pairs polymorphic microsatellite loci.The result showed that H.bodinieri populations had rich genetic diversity.The average observed allelic number(Na)and the effective allelic number(Ne)were 3.903 and 2.545 respectively.The mean expected heterozygosity(He)was 0.521 and Shannon's diversity index(I)was 0.962,PIC=0.465.Using GENEPOP software,Hardy-Weinberg equilibrium testing shows that 4 primers obviously deviated from HWE expectations.Natural populations of H.bodinieri had relatively high level of genetic diversity,however the genetic diversity of the populations were reduced due to because of sabotage etc.Nei's genetic differentiation coefficient(Gst)was 0.027,G'stN=0.031,G'stH=0.064,gene flow(Nm)was 3.368.It showed the genetic variation of H.bodinieri occurred mainly within populations.AMOVA analysis showed that 3% genetic variation occurred among populations,97% genetic variation occurred within populations.Mantel test showed that there was positive correlation between genetic distance and geographical distance(r=0.299,P<0.05).The genetic identity among 8 populations of H.bodinieri was between 0.849 and 0.970,genetic distance among 8 populations was between 0.032 and 0.164.UPGMA clustering based on Nei's genetic distance showed that it could be divided into 2 groups.Ten DNA regions were sequenced for gene sequencing study on H.bodinieri.These ten DNA regions were chloroplast DNA including rpl32-trnL,trnH-psbA,trn L-F,trnS-G,trnT-L,matK,trnH-trn K and rps16,nuclear ribosomal DNA internal transcribed spacer(nrDNA ITS)included ITS1-4 and ITS5f-2r.960 gene sequences containing a total of 2627 bases were analized based on cpDNA and ITS.Mismatch Analysis chart,it is not possible to determine whether the H.bodinieri group has had the expansion.Genetic distance ranged from 0.000 to 0.001.Using Aesculus chinensis Bunge as an outside group for phylogenetic reconstruction,the results showed that 96 individuals of H.bodinieri belonged to a single branch,which was a typical manifold branch.The low gene variation may be related to the woody habit of H.bodinieri on the one hand,on the other hand the ancestors of H.bodinieri might experience extinction event,the existing populations are descendants of few ancestral individuals.Further analysis can not be conducted based on gene sequence.