Studies On Genetic Diversity Of Abietinella Abietina In Northern China And Mongolia And Phylogeography To Wudalianchi Volcanic Group,China

Abietinella abietina,a widely distributed moss in montane of Holarctic kingdom,has a significant effect on the regeneration and development of coniferous forests at high altitude,however,its genetic characteristics of morphological variation and the relationship between evolution and volcanic eruptions have not yet been cleared.Using ISSR primer with 140 individuals from 10 natural populations on a large scale,genetic diversity of A.abietina in northern China and Mongolia was studied to evaluate its genetic variation and structure and establish reasonable strategies for the conservation.Futhermore,using nuclear gene,chloroplast gene and ISSR primer with80 individuals from 6 natural populations on a fine scale,phylogeography of A.abietina in wudalianchi volcanic group was studied to assess its cuttent patterns of genetic diversity and conjecture the propagation path and the ancestral distribution.The main results were described as follows:?The results from orthogonal design with 4 levels of 5 factors showed that the optimum ISSR-PCR reaction system of A.abietina was 25?L total volume containing Taq DNA polymerase 0.8 U,Mg²⁺2.5 mmol/L,d NTPs 0.4 mmol/L,primer 0.6?mol/L and template DNA 40 ng.The sequence of the effective factors was Taq DNA polymerase>Primer>d NTPs>Template DNA>Mg²⁺.Meanwhile,12suitable ISSR primers and the annealing temperature of selected primers were screened from 100 universal ISSR primers.?Compared to other bryophytes and angiosperms,A.abietina had higher genetic variation in northern China and Mongolia at the species level.The highest amount of genetic diversity in northwestern China group,followed by northeastern China group and Mongolia group at the regions level.Among all 10 populations,the highest genetic diversity occurred in population SYK,whereas the lowest level in population HTGT.Results from AMOVA analyses showed that the highest proportion of genetic variation partitioned within populations,followed by the variation among groups,and the variation among populations within groups.According to the UPGMA,PCoA and STRUCTURE analysis,10 populations were clustered into 3main groups,in which the northwestern China group formed an independent branch while the northeastern China group and Mongolia group constituted sister groups,corresponding to their geographic origin.In addition,the significant positive association between genetic distances and geographic distances was detected by the Mantel test.?According to the selected 1 nuclear gene sequence?nrITS?and 3 chloroplast gene sequence?trnL-F,atpB-rbcL and rps4?,5 nrITS haplotypes and 10 cp DNA haplotypes were indentified from 6 populations of A.abietina in wudalianchi volcanic group,respectively.The population genetic diversity of the new-period volcanos that HS and HL was higher than the old-period volcanos that LM,XJDB,MLB and DJDB.Results from AMOVA analyses showed that the genetic variation within populations higher than among populations.Although a significant phylogeographic structure was not detected at the species level,it was detected at lineage B on account of cp DNA sequence.The TCS haplotype network diagram and phylogenetic analysis of MP,ML and BI consistently recovered two clades:Lingeage A and Lingeage B,in which Lingeage B can be further divided into two subclades that MLB-LM-XJDB lingeage and HS-HL lingeage based on nrITS haplotypes or three subclades that MLB lingeage,LM-XJDB lingeage and HS-HL lingeage based on cpDNA haplotypes.In addition,population expansion of A.abietina was not detected by Mismatch distribution analysis and Neutral test.