Genetic Diversity Of Eucommia Ulmoides In Anhui Province Based On ISSRs

Eucommia ulmoides Oliv. is a tertiary relict plant and valuable medicinal woodyplant endemic to China. This thesis is composed of two parts:（1） establishment ofSSR-PCR reaction system and primers screening for E. ulmoides;（2） genetic diversity of E.ulmoides in Anhui province based on ISSRs.Simple sequence repeat-polymerase chain reaction （SSR-PCR） system wasestablished through orthogonal test and optimized through single factor experiment. Theresults showed that the optimal SSR-PCR reaction system was a volume of10.0μLcontaining forward-and reward-primer (10μmol·L^-1)0.2μL, respectively, Taq DNApolymerase (5U·μL^-1)0.1μL, dNTP (10mmol·L^-1)0.2μL, DNA(5-10ng·μL^-1)1.0μL,Mg2+(25mmol·L^-1)0.6μL,10×PCR buffer1.0μL and HPLC water6.7μL. Three SSRpolymorphic primer pairs were selected. The results proved the limited transferability ofSSR primers between distantly related species, revealed the genetic diversity of E.ulmoides preliminarily, and exhibited the advantages of SSRs for the investigation ofgenetic diversity.The genetic diversity within and among populations of E. ulmoides Anhui provincewas assessed using inter-simple sequence repeat markers （ISSRs）. A total of107individuals from four populations were investigated at200polymorphic loci with14primers. The results indicated the mean values at the population level for the percentage ofpolymorphic loci （PPLp） of45.25%, Effective number of alleles （nep） of1.199, the Nei’sgene diversity （Hep） of0.126, and the Shannon’s information index （Ip） of0.198. At thespecies level, PPLs=100.00%, nes=1.215, Hes=0.164, Is=0.292. Genetic differentiation（Gst） indicated that23.19%of total genetic diversity were attributed to the differencesamong populations. Analysis of molecular variance （AMOVA） revealed that geneticvariation among and within populations accounted for40.40%and59.60%of the totalgenetic variation, respectively, showing the most genetic variation was found withinpopulations. The UPGMA cluster analysis separated the four populations clearly, andshowed no correlation between population grouping and geographic distribution. Theresults of present study will provide important information for conservation, exchange, andsustainable utilization of genetic resources, and tree breeding of E. ulmoides.