Genetic Diversity Of Primula Cockburniana By AFLP Analysis

In this paper,10 populations 143 individuals of Primula cockburniana from Kangding Yajiageng,Mt.Zheduo and Danba Tiantanggu-dangling were sampled and analyzed by using amplified fragment length polymorphism(AFLP)makers.Genetic diversity and genetic structure of it were indicated to providing insight for the conservation and breeding of this species.The main results were as follow.1.Amplified results:A total of 6 AFLP primers combinations were employed on 143 individuals of P. cockburniana.These primers generated 546 bands,of which 218 were polymorphic.The bands mainly distributed among 100-850bp.2.Genetic diversity:At species level,the percentage of polymorphic loci(PPL)was 39.93%,Nei's gene diversity(He)was 0.0990,and Shannon's information index(l)was 0.1563,respectively. At population level,the estimates of PPL was 16.12%(7.33%～24.91%),He was 0.0619 (0.0296～0.1034),I was 0.0907(0.0430～0.1484).Among 10 populations,Yajiageng(3090m) was revealed the highest variability,whereas Dangling(3410m)was revealed the lowest variability.The genetic diversity is low.In three groups,the genetic diversity of Yajiageng is the highest,whereas Mt.Zheduo is the lowest.The result displayed that the lower altitude was,the higher genetic diversity was.3.Genetic structure and genetic differentiation:In the 10 populations,Ht was 0.0961,Hs was 0.0619 and Gst was 0.3557.It suggested the genetic differentiation within populations.Compared group Yajiageng with group dangling,it also suggested the genetic differentiation within populations,but Ht and Hs of group Yajiageng was higher than the latter.The result of AMOVA complied with the results of gene differentiation coefficient analysis.The average gene flow(Nm)was 0.9056＜1,suggesting that lower frequency existed in populations,but group yajiageng's Nm=1.3617＞1 and group danba's Nm=1.0554＞1 revealed higher frequency existed in populations of group so that it was moderate. 4.Genetic identity,genetic distance and clustering:The means of genetic identity was 0.9619(0.9293～0.9854)and genetic distance was 0.0389(0.0147～0.0733).The genetic identity between Yajiageng(3090m)and Dangling(3410m)was the lowest(0.9293)and the genetic distance was the highest (0.0733),to the contrary,between Dangling 3410m and 3600m the genetic identity was the highest(0.9854)and the genetic distance was the lowest(0.0147).They had been distributed into two clades but couldn't be divided according to the distribution.The genetic identity between group Yajiageng and Mt.Zheduo was the lowest(0.9633) and the genetic distance was the highest(0.0374),whereas genetic identity between group Yajiageng and Dangling was the highest(0.9819)and genetic distance was the lowest (0.0183).Though distance between Mt.Zheduo and Dangling was longer than between Yajiageng and Mt.Zheduo,the relationship was closer.They had been distributed into two clades,one including Yajiageng,another including Mt.Zheduo and Dangling.The dendrogram for 143 individuals displayed they hadn't been clustered on the basis of their distribution of population.Gene differentiation within populations was apparent, among populations was different and there were some gene drift within populations.In spite of huge size,more quantity,extensive distribution,the genetic diversity of P.cockburniana was low in this study,and gene differentiation most existed in population.Based upon the above mentioned results,the policies of conservation management were indicated.