Analysis Of Genetic Diversity Of Chinese North Coastal Protective Forest Of Pinus Thunbergii By SRAP

Japanese black pine (Pinus thunbergii Parl.) is a species native to coastal areas of Japan.Its main uses are in shoreline plantings, wind breaks and as an accent tree in the landscape.the Japanese black pine has played an important role in protection against wind and thecontrol of soil erosion, since it is well adapted to conditions along the coast and the lowmountains running along the coastline. At the beginning of the last century, it was introducedinto China and now it is widely plant all over the country. The objective of the study is toevaluate the genetic diversity and genetic structure within and among11stands of Japaneseblack pines from China detected by SRAP for the breeding and cultivation proving the basis.The main results from this study are as follows：1、A rapid and stable system applied for genetic diversity study of Pinus thunbergii wasdeveloped: Genomic DNA was extracted from leaves of Japanese black pine by the method ofmodified CTAB. We obtained high quality and purity genomic DNA which can meet therequest of PCR reaction. Using of SRAP markers combined with non-denatured polya-crylamide gel electrophoresis screened the repeatable SRAP loci with high polymorphism.2、SRAP polymorphism primer screening of Pinus thunbergii:7primer pairs were selectedfrom225pairs, which were applied to study the genetic diversity and relationships of thematerials.7primer pairs produced73loci of which59were polymorphic, the percentage ofpolymorphic loci was80.82%, each primer combination produced10.4loci and8.4poly-morphic loci; Percent of Polylnorphic loci in11stands of Pinus thunbergii was54.79％~64.38％with an average of60.64％.3、Genetic diversity of Pinus thunbergii: At species level, Effective number of allels (Ae)was1.5901, Nei’s gene diversity (H) was0.3279, Shannon’s Information index (I) was0.4759. At population level, the average value of Ae was1.4465, the mean value of Hamounted to0.2468, the general average of I was0.3581. It was basically identical thatgenetic level in11stands by effective number of allele (Ae), Nei’s Index (H) and ShannonIndex of diversity (I). The highest diversity was found in the Dayao stand. The lowestdiversity was found in the Jincheng stand. Furthermore, The significance difference did notexist in genetic diversity of11stands by analysis. 4、The genetic structure within and among11stands of Pinus thunbergii: The percentage ofgenetic diversity within Japanese black pine stands was75.74%in the total value, thepercentage of genetic diversity among the Japanese black pine stands was24.26%, that meansthe genetic variation was mainly occurred inner Japanese black pine stands. The mean of geneflow(Nm) was1.5612, which showed relatively steady gene flow among stands, reducedgenetic variance.5、Cluster analysis among11stands of Pinus thunbergii: Base on the UPGMA clusterdiagram, the11stands may be divided with the genetic distance of0.115into three groups.The result was not completely consistent with the traditional division of stands. Theindividuals from the same stand did not completely cluster together.