The Application Of SSR Markers In Forest Tree Fine Varieties Identification And Construction Of Fingerprints Of Chestnut Cultivars

The phenomenon that tree species of homonym and synonym is very common,because of the way the forest reproductive diversity and frequent exchanges around the forest in the forest breeding work,which has a bad effect on tree species breed,management and promotion.To standardize the management of forest varieties promote the validation of forest varieties and protect new varieties,It’s urgent to establish economic,convenient,efficient and accurate identification standard for forest varieties.With the reduction of forest gene pool and the emergence of close relatives,it’s inaccurate to use conventional morphological identification,physical and chemical identification and biochemical identification in the identification of resolution of forest varieties.The method of molecular markers in the genomic layer to identify the varieties ensure a high degree of accuracy of the identification become a a powerful tool in identification of forest species.In this study,nine SSR identification techniques were established by simple sequence repeats(SSR)and the varieties of Hebei Province were identified and analyzed in 2016 has been proved,At the same time,51 chestnut cultivars were collected and SSR technique was used to establish DNA fingerprints.The main findings are as follows:1.The SSR molecular marker technology system of 9 tree species was established.121 pairs of primers were screened and 31 fingerprints of 9 species were used to identified DNA fingerprints by it,Of which 19 varieties of hybrid,9 varieties of breeding,3 varieties of buds.A total of 89 samples were obtained from 31 approved samples and 58 control samples.The three types of different identification types were used to analyze the different types of SSR.The results show that the SSR molecular marker method is stable and reliable,and the accuracy is high.It is especially suitable for the identification of the parents and the identification of the breeding varieties.Because of the small number of SSR loci and the inability to detect the mutation of single base,the budding species can only identify whether the origin of the mutant is the same as that of the parent variety with budding traits.2.Fingerprints and DNA fingerprint data of 51 Chinese chestnut cultivars were constructed by SSR molecular marker technique.A total of 33 loci were amplified by PCR with 8 pairs of SSR primers by detected to 51 Chinese chestnut cultivars and 100% were polymorphic.The average number of loci was 4.13 loci.the number of amplified sites are2～9,the polymorphism information content(PIC)value range of 0.286 ～ 0.690,an average of 0.473.The DNA bands amplified by capillary electrophoresis were analyzed by UPGMA method 0-1.The genetic distances were between 0.069 and 0.520,and were classified into three groups at the genetic distance of 0.447,which could not be classified according to their origin.8 pairs of primers were combined to isolate 51 Chinese chestnut cultivars,and the number of alleles in SSR loci was large,which effectively revealed the genetic diversity of chestnut.The map codes of 51 chestnut cultivars were constructed and sorted with SSR primer sequence.The QR code of DNA fingerprint data was generated by using QR code generator of forage,which provided the basis for the identification of new varieties and germplasm resources of chestnut.