Genetic Diversity And Genetic Structure Of Juniperus Sabina L. Population In Inner Mongolia And Its Surrounding Areas

In this experiment,nine wild populations of Juniperus sabina L.(221 individuals)distributed in Inner Mongolia Autonomous Region and its surrounding areas were selected as experimental materials.The trnL-trnF,trnS-trnG and trnD-trnT sequences of chloroplast DNA were sequenced.By analyzing the variation of chloroplast DNA sequence,the haplotype type was obtained,and the genetic diversity index of Junipenrus sabina population was calculated.The population structure of Juniperus sabina was estimated and the genetic relationship among haplotypes was deduced.The main results are as follows:The total length of sequences obtained by sequencing trnL-trnF,trnS-trnG and trnD-trnT sequences of Juniperus sabina chloroplast DNA gene spacer region was 2068-2073 bp.Three mutations were observed,4 haplotypes(H1,H2,H3 and H4)were obtained after the combination of mutation sites,in which haplotype H1 number of individuals was the most,haplotype H3 was the least.The haplotype diversity index(Hd)of 9 Juniperus sabina populations was between 0 and 0.239,with an average of 0.072.The nucleotide diversity index(7r)ranged from 0 to 0.00063 with an average of 0.00014.The gene differentiation coefficient(Gst)was 0.045 and the fixed index(Fst)was 0.071.The results showed that the genetic bottleneck effect was obvious,the genetic variation among populations was low,and the genetic variation among populations was higher.