Genetic Diversity Analysis Of Verticillium Dahliae Population On Cotinus Coggygria In Beijing Region

Smorke-tree (Cotinus conggygria Scop.) which can be infected by Verticillium dahliae is an important kind of ornamental tree species and play an important role in the landscape construction in Beijing. V. dahliae is a soil-borne plant pathogenic fungus. It is survival in soil with a long time and there is not a useful control management. In order to analysis population genetic diversity of V. dahliae on smoke-tree,179isolates coming from Beijing and Shandong province were used and divided into six populations by the different geographical origin. Population genetic diversity was studied based on the SSR molecular marker, and provided the theoretical support to control the smoke-tree wilt. Main results are as follows:1.51pairs of SSR primers were designed by the reported SSR loci and used to and the validity of resulting primer pairs was detected by amplifying10isolates of V. dahliae from different geographical origins. Under the established SSR reaction system,6primer pairs which produced effective and polymorphic fragments were selected to analyze the genetic diversity of179V. dahliae isolates.2. On the6SSR loci, a total of26alleles were detected in179isolates. At each locus,2-7alleles were detected with an average of4.22. On the level of species, effective number of alleles (Ne) was1.4399, Nei’s gene diversity was0.2715, Shannon’s information index was0.4251, the results indicated the genetic diversity existed among the populations. The highest one was found in Changping population and the lowest in Baiwangshan population.3. The result of genetic differention among6populations showed that it could be found within and among populations. The gene diversity in the species (Ht) was0.2748and the gene diversity within populations (Hs) was0.2410. The majority of genetic variation occurred within populations. Gene flow among populations was high (Nm=3.5665) and made the populations had the trend to be consistent.4. According to the genetic similarity coefficient, the six populations were clustered into two groups by UPGMA method. One group included Yanqing population and Licheng populaton. Other four populations coming from Beijing were in the other group. It implicated that the population genetic diversity was not consistent with the geographic distance.