Study On The Karyotype Analysis Of Pulsatilla Plant And Diversity Of Germplasm

Objective:Confirm the chromosome karytype of Pulsatilla in YanBian and the inner relationship between genetic diversity and morphological diversity.Methoe:①We cultivated the seeds of P.cernua and P.dahurica in YanBian with sand, after cutting the root tips of the sprouts we preprocessed them with 0.2% colchicine for 4h and fixed them with carnoy's fluid I for 24h.We dyed the root tips with carbolfuchsin and used conventional methods to cover the tips with a piece of tiny glass,then studied the details using the microscope. We sealed and kept samples with neutral balsam. The method of karyotype we took Levan's (1964).③Genomic DNA is extracted from 14 different groups of Pulsatilla with improved CTAB method. We used 11 primers to amplify DNA. The cluster analysis we took is UPGMA.Results:①Both the chromosome number of P.cernua and P.dahurica are 2n=16, the karyotypic formula of P.cernua is 2n=10+6st, the change territory of relative length which belong to chromosome is 8.88-16.68. The average arm ratio is 1.89; the karyotypic formula of P.dahurica is 2n=10m+2sm+4st, the change territory of relative length which belong to chromosome is 9.20-17.45. The average arm ratio is 2.03.②There are 172 amplified bands from 11 primers,137 of which are polymorphic, the percentage of polymophic bands (PPB) is 79.65%. When the genetic distance is 0.48, It is divided into two groups:P.cernua and P.dahurica. When the genetic distance is 0.405, P.cernua could be classified into two subclasses.When the genetic distance is 0.305, P.dahurica could be classified into two subclasses.Conclusion:①The difference of chromosome 6 between P.cernua and P.dahurica explains that there are differences of chromosome among species.②It shows that the genetic distance between different species is farther, each species has different degrees of diversity.