| Sinowilsonia fienryi Hemsl is a deciduous tree,which is endemic to China,and now it’s also nationalsecondary protection plant. Sinowilsonia fienryi Hemsl is mainly distribute in Henan,Shannxi,Gansu,Hubeiand Shanxi among1100to1600meters of hills,valley and forest of banks. It’s a good tree for protect bankof river because it can endure shot intermittent water leaching by it’s developed root system; it’s also anornamental plant for its flourish leaves, beautiful tree posture and peculiar infructescence.So it has a widedevelopment prospect.In recent years, molecular markers have been widely used in studies of plant genetic diversity.AndISSR was used to study the genetic diversity of Sinowilsonia fienryi Hemsl in this study, thus to reveal itsmainly distribution and genetic differentiation among populations, understand relationships of differentpopulations, in addition to protect and rationably utilize the germplasm resources of the endangeredspecies. The results showed suggested that:1. Optimization for ISSR reaction system.The best ISSR-PCR system was:20μL reaction system withrTaq10μL, primers2μL, template DNA1μL, ddH2O complement20μL;the reaction program was:95℃previously denaturation4min;94℃denaturation45s,48~60℃annealing30s,72℃extension90s,35cycles;72℃extension8min in total,4℃preservation;2.85polymorphic bands were detected from total89bands using10primers;percentage ofpolymorphic bands(PPB) was95.5％; suggesting that Sinowilsonia fienryi Hemsl had a high level ofgenetic diversity at species level;3. Nei’s gene diversity(H), Shannon’s information index(I), the coefficient of gene differentiation (Gst)and the percentage of total variance among and within populations were0.2833,0.4034,0.3507,25.49%and74.51%, respectively, indicating that there was a significant genetic differentiation both within andamong the populations, and genetic diversity was mainly derived from the differentiation withinpopulations;4. UPGMA dendrogram showed that at the specify threshold which was0.87Sinowilsonia fienryiHemsl species were separated into3clusters, that germplasm repository in Huo Ditang, botanic garden inXi’an, Shi Bangou in Ningxi, Chou Chungou in Ningxi and Mu Hegou in Ningxi were clustered together,among this germplasm repository in Huo Ditang and botanic garden in Xi’an, Chou Chungou in Ningxi andMu Hegou in Ningxi were clustered more closer. Hei Longgou in Jiyuan and Hei Longtan in Jiyuan wereclustered together; and Jin Sixia in Shangluo was clustered alone. It showed that most individuals which came from same habitat were clustered, suggesting that there might be a relationship between clusteringanalysis and geographical distribution. |
