The Phylogeny Study Of Acer L.sect. Trifoliata Pax

Acer sect.Trifoliata Pax,of which the flowers are hermaphrodite,having palm-shaped compound leaf,belonging to genus Acer L.,Aceraceae,Sapindales,distributes in northeastern China,Henan,Hubei,Shanxi,Sichuan,etc.The species of Sect.Trifoliata have important landscape and great medicinal values.In this study,9 pairs of polymorphic SSR primers were developed based on Acer triflorum Komarov.Based on SSR molecular marker technology,SSR primers were amplified in 202 individuals of A.triflorum,Acer griseum(Franchet)Pax,Acer nikoense Maximowicz,Acer shensiense Fang et L.C.Hu,Acer mandshuricum Maximowicz,Acer mandshuricum Maxim.subsp.kansuense(Fang et C.Y.Chang)Fang and Acer sutchuenense Franchet,based on which,study on the phylogeny of Sect.Trifoliata could be carried out.Based on 9 pairs of SSR primers,a total of 101 alleles were amplified in 202 individuals,and an average of 11.2 alleles were amplified from each pair of primers,the average observed heterozygosity(Ho)of the species ranged from 0.005 to 0.946 and the expected heterozygosity(He)ranged from 0.344 to 0.873.Most of the microsatellite loci in A.triflorum,A.griseum and A.mandshuricum showed a serious deviation from the Hardy-weiberg equilibrium(p<0.001),the cause might be that Sect.Trifoliata did not follow the pattern of random mating,and the loci were affected by genetic mutation,natural selection or some other factors.In populations of A.mandshuricum,He is less than Ho,indicating that the populations had higher hybridization degree and higher genetic diversity,as while A.mandshuricum might have a relatively long evolutionary history and is more changable.According to the analysis of population genetic structure,the Fst value was 0.227,which indicating that the genetic variation among the species showed moderate differentiation.The Nm value was 0.288,indicating that the gene exchange activities between various populations of Sect.Trifoliata were somewhat restricted to a certain extent.The best K value was 3 by STRUCTURE analysis.A.mandshuricum and A.mandshuricum subsp.kansuense converged into a single branch,A.triflorum was clustered in one group,A.griseum,A.nikoense,A.shensiense and A.sutchuenense were clustered in the other same group.Through population and PCA analysis,A.triflorum,A.griseum,A.nikoense,A.shensiense and A.sutchuenense showed a close genetic relationship,A.griseum and A.shensiense neared genetic similarity,so did A.mandshuricum and A.mandshuricum subsp.kansuense.This study is helpful to reveal and understand the phylogenety of Sect.Trifoliata,and is also useful for the future research of the speciation of the genus Acer.As while to make more efficient play of the economic and ecological value of Sect.Trifoliata.