Genetic Analysis Of Quercus Variabilis Population By CpSSR

Quercus variabilis is one of the main constituents of deciduous broad-leaved forests in temperate and subtropical areas in China.It is important material and has many useness. In this paper the genetic analysis of 24 natural Q.variabilis populations from 4 provinces of China is studied by using chloroplast simple sequence repeats(cpSSR) marker. Based on the analysis,the the strategies to conserve the germplasm resources of Q.variabilis were also discussed. The main results are as follows:27 pairs of primers are used to amplify 120 samples and clear production can be amplified by 25 pairs of primers.20 of them are nonpolymorphic and 5 of them are polymorphic( 7 polymorphic loci are available) .Through the inspect of 7 loci,there are altogether 14 haplotypes.21 populations have one haplotype within themselves.The area of DaBie Mountain in Anhui province has the richest haplotypes and there are 10 haplotypes in this area. Most haplotypes in distribution fringe can also be seen in distribution centre.After the forth ice age,the areas of DaBie Mountain,Eastern Chuan and Western Yue which are the"sanctuary"had become the original place of plant heterogenetic differentiation for it's complex physiognomy and multiple environment.During the long period of evolution,the cold resistant differentiation occupied the high latitude area and the hot resistant differentiation occupied the south area.So today's distribution pattern had been formed.Average number of alleles(A) and effective number of alleles(Ne) are 2.5714 and 1.5281. Nei diversity index and Shannon information index are 0.2836 and 0.5009.These parameters are much lower than the ones revealed by nucleus genome SSR. Coefficient of genetic differentiation(Gst) is 0.9429 on average.It's opposite to the conclusion revealed by nucleus genome SSR which shows a low Gst.It proves that cpSSR is more suitable for revealing the differences between populations.Q.variabilis genetic diversity center is consistent with today's distribution center.DaBie mountain area and the area between Western Chuan and DaBie mountain area are both genetic diversity center and distribution center.To conserve the genetic diversity of Q.variabilis,we should not only emphasis on the population from distribution centre but also protect population from distribution fringe especially to protect the different adaptability differentiation.