Analysis Of Provenance Variations In Seedlings And CpDNA Geographic Subdivision Of Quercus Variabilis

Quercus variabilis is one of the most typical species of deciduous broad-leaved forests in warm-temperate and subtropical areas in China. Seeds of different provenance were collected from main distribution regions of Q. variabilis for analyzing the variations of seeds and their seedlings. The genetic analysis of 34 natural Q. variabilis populations from 12 provinces of China was studied by using PCR-RFLP and cpSSR.The results of variations of seeds and their seedlings showed that there were significant differences in size of seed, seed weight, germination rate and seedling growth among provenances. The seeds collected from centre distributions, compared with those from other areas, possessed larger seed size, higher germination rate as well as more exuberant growth during seedling.Based on the PCR-RFLP and cpSSR, 17 haplotypes were observed among 15 populations by using 4 cpDNA fragments of PCR-RFLP; 27 pairs of cpSSR primers were used to amplify 34 populations and 5 of them were polymorphic in 13 polymorphic loci. Through the 13 loci, there were 10 haplotypes in all. The primary haplotypes'variations occurred among populations, the coefficient of genetic differentiation (Gst) among populations were 0.8132PCR-RFLP and 0.8742cpSSR, 18.68%PCR-RFLP and 12.58% cpSSR was taken up by genetic diversity among the populations.It might be inferred on the basis of haplotype that: during the quaternary glacial period, Q. variabilis on the north of Qinling Mountains in high latitudes turned out to be gradually died out for the reason that they could not put up with the cold weather generated by the glacier of Taibai Mountain in Shanxi.The south of Qinling Mountains,Eastern Chuan and Dabie Mountains were the"sanctuary"of Q. variabilis as well as the main distribution. As the enviroment recoverred after the glacial period, Q. variabilis spread from"sanctuary"to the north once again until it reached up to the Liaoning province. Far less influenced by the Quaternary climate, Q. variabilis in the low latitudes areas of the south and southwest of China still dipersed widely, with small amount of exchanges and interaction with the populations in the main distribution.