Primary Analysis Of Genetic Diversity Of Populations Of Pinus Tabulaeformis In Shanxi

This study was conducted by isozyme marker with 140 individual of 5populations to determine genetic variation and population genetic structure ofP. tabulaeformis. The current situation and rules of the genetic diversity in thestudied population were revealed. Moreover, primary analysis was conducted bySSR marker. These findings will provide the theoretical references and scientificbasic data for gene resources conservation, genetic improvement and sustainedutilization in P. tabulaeformis. The main results of the research were as follows.(1) The results of isozyme marker analysisThe POD and PPO were used as marker to determine the genetic diversity ofP. tabulaeformis in Shanxi. It showed that the percentage of polymorphic loci(P)was 95%, the mean number of alleles per locus(A) was 1.950 and the averageexpected heterozygosity(He) was 0.362 in 5 populations of P. tabulaeformis. Itindicated that there was a relatively high level of genetic diversity inP. tabulaeformis, and demonstrated relatively mediate to higher level of geneticvariation within species. The genetic differentiation of populations was 0.036 onaverage and the majority of genetic variation occurred within populations. Themean of gene flow(Nm) was 6.73, which showed relatively high level of geneflow among populations. Continued distribution, long life, predominantlyoutcrossing, wind pollination and high gene flow might be the main causes of lowgenetic differentiation of populations of P. tabulaeformis.Dendrogram resulting from UPGMA method clustering based on geneticidentity showed that the five population are divided into three branch,Guanqingshan and Guandishan population cluster into one branch, Lishan andZituanshan population cluster into one branch, Lingkongshan population is onebranch independent. In addition, no significant correlation was found betweengeographical distance and genetic distance in populations of P. tabulaeformis(r=-0.1567, P=0.333). Relationship between genetic variation and factors ofgeography and ecology showed that latitude had negative significantly correlationwith POD-2A gene frequency (r=-0.898, P=0.019 ), and had positive significantly correlation with POD-2B gene frequency(r=0.898, P=0.019); annualaverage amount of precipitation had negative significantly correlation withPOD-1A (r=-0.924, P=0.012), and had positive significantly correlation withPOD-1B gene frequency (r=0.924, P=0.012) and fixation index (r=0.911, P=0.016).(2) Screen of SSR markerPCR experiments were conducted by using ten pairs of primers of SSRmarkers and genomic DNA of 140 individual of 5 populations ofP. tabulaeformis. Two pairs of SSR primers have been obtained, which could beused to amplify clear bands on agarose gel electrophoresis. It would provide basicdata for further study on genetic diversity of populations of P. tabulaeformis byusing SSR marker.