Study On Population Genetic Diversity Of Symplocos Paniculata In Changbai Mountain Area

Symplocos paniculata?Thunb.?Miq.is an important species of genus Symplocos,family Symplocaceae.It is widely distributed in most parts of China.With beautiful white flowers and blue berries,it has high ornamental value.It also has excellent development and utilization potential for its high content of fats and anthocyanins in berries.In order to provide the theoretical reference for collection,screening and comprehensive development and utilization of excellent germplasm resources,genetic diversity of different wild populations of Symplocos paniculata in the Changbai Mountain area were investigated by using morphological,ISSR and SRAP makers.The results are as follows:1.Phenotypic variation types of Symplocos paniculata were very rich.The phenotypic traits average diversity index were more than 4.5 respectively,and coefficient of variation was13.96%,the fruit characters had the highest degree of variation.10 of 16 phenotypic traits existed extremely significant differences among and within 18 populations in multiple comparison of Duncan.The results of PAC indicated that the first 8 main factors could be used to represent the phenotypic traits with accumulative contribution up to 75.24%.2.The combination of single factor test and orthogonal test was used to optimize SRAP-PCR reaction system.A suitable SRAP-PCR system for Symplocos paniculata was established,the total 10?L reaction system containing 0.75U Taq DNA polymerase,0.1mmol/L dNTPs,2mmol/L Mg²⁺,0.4?mol/L primer and 80ng DNA.25 polymorphic SRAP primer combinations screened from 176 SRAP primer combinations were used to analysis the genetic diversity of 96 samples of Symplocos paniculata.A total of 306 bands were amplified by SRAP primer combinations,in which 240 bands were polymorphic bands,the percentage of polymorphic bands was 78.12%.3.The analysis of SRAP markers showed that genetic diversity of Symplocos paniculata reache quite high level and exist certainly difference among different populations.According to polymorphic percentage,Nei's gene diversity and Shannon's Information index,the genetic diversity level of A population was highest,C population was lowest.The genetic diversity degree of Symplocos paniculata was quite high in populations and species,genetic variation mainly existed within populations but not among populations.Symplocos paniculata populations existed frequent gene flow?Nm=5.21?and quite low degree of gene differentiation?Gst=0.09?among populations,the genetic distance was small,between 0.05⁰.10.UPGMA cluster analysis showed 3 group types among 4 wild populations of Symplocos paniculata.4.The combination of single factor test and orthogonal test was used to optimize ISSR-PCR reaction system.A suitable ISSR-PCR system for Symplocos paniculata was that total 10?L reaction system containing 0.75U Taq DNA polymerase,0.1mmol/L dNTPs,2mmol/L Mg²⁺,0.5?mol/L primer and 80ng DNA.22 polymorphic ISSR primers screened from100 ISSR primers were used to analysis the genetic diversity of 96 samples of Symplocos paniculata.A total of 259 bands were amplified by ISSR primers,in which 207 bands were polymorphic bands,the percentage of polymorphic bands was 79.45%.5.The analysis of ISSR markers showed that genetic diversity of Symplocos paniculata reache quite high level and existed certainly difference among different populations.According to polymorphic percentage,Nei's gene diversity and Shannon's Information index,the genetic diversity level of A population was highest,D population was lowest.The genetic diversity degree of Symplocos paniculata was quite high in populations and species,genetic variation mainly exist within populations but not among populations.Symplocos paniculata populations existed frequent gene flow?Nm=5.30?and quite low degree of gene differentiation?Gst=0.08?among populations,the genetic distance was small,between 0.06⁰.13.UPGMA cluster analysis showed 4 group types among 4 wild populations of Symplocos paniculata.The combination of morphological markers and molecular markers is beneficial to the genetic diversity of Symplocos paniculata.