Genetic Diversity Of Quercus Acutissima And Q.variabilis Based On AFLP Markers And Fast-growing Family Selecting

Quercus(Quercus L.)is about 450 species,which is widely distribution,as well as it has important economical,ornamental and ecological value.Shandong province is one of the main topographical region of Q.acutissima and Q.variabilis.Unfortunately,some primary species of Q.variabilis and Q.acutissima were destroyed with the production of human activities.We collected the seeds of 27 half-sib Q.acutissima families and 19 half-sib Q.variabilis families from Shandong Province,and then proceeding the forest cultivation.The genetic diversity,genetic structure and genetic relationship were analyzed through the using of amplified fragment length polymorphism(hereafter AFLP).The 1-year,5-year and 8-year old parameters of seedlings growth and leaves were measured aiming to select the fast-growing families,whereas it could provide theoretical basis of the evaluation,protection and utilization of the germplasm resources in Q.acutissima and Q.variabilis.As the results showed:1.Genetic diversity of Q.acutissima: 8 primer combinations selected from 64 primer combinations showed that a total of 1440 fragments and polymorphism percentage of 100%produced by 72 accessions.The average of four indexes(Na,Ne,H and I)were 2.000,1.2638,0.1731 and 0.2871,respectively,which indicated that Q.acutissima had a high genetic diversity.Genetic similarity coefficient(SC)of the 72 single plants changed from 0.3048 to0.7597,moreover,most of the plants from the same half-sib family were clustered together.There were 61 accessions in 72 germplasm of Q.acutissima producing a total of 209 specific bands,which were single and not absent.Polymorphism percentage of 9 half-sib families of Q.acutissima changed from 42.17% to 54.29%,in which the average polymorphism proportion was 48.72%.The order of polymorphism percentage from big to small was: Shiliu yuan32>Mengyin 50>Seismic station 39>Longkou 48>Sanyang temple22>Laiyang 52>Dong pozi 43>Hongmen 16> Mountain Culai 46.2.The genetic structure of Q.acutissima showed that: Gst was 0.2478 and Nm was1.6517.They suggested that genetic variation mainly came from the population geneticvariants that had a certain gene exchange between different families.Genetic identity ranged from 0.9082 to 0.9808 with the average value of 0.9507.Genetic distance changed from0.0194 to 0.0753 with the mean value of 0.0493,but the genetic similarity coefficient was high between different families.All of the 9 half-sib families were clustered into 4 groups at0.044,and Metal test showed that there was no correlation between the genetic distance and geographic origin of the Q.acutissima(r=0.1133,p=0.7169).3.Genetic diversity of Q.variabilis showed that: 8 primer combinations selected from64 primer combinations showed that 82 accessions produced a total of 1438 fragments,with a polymorphism percentage of 100%.The average of four indexes(Na,Ne,H and I)were 2.000,1.2903,0.1868 and 0.3050,respectively.This result indicated that Q.variabilis had a high genetic diversity.Genetic similarity coefficient(SC)of the 72 single plants changed from0.3229 to 0.7010.Plants from the same half-sib family,were not first clustering together.There were 60 accessions within 82 accessions of Q.variabilis producing a total of 176 specific bands,and all of them were single and not absent.Polymorphism percentage of 12half-sib families of Q.variabilis changed from 36.61% to 59.81% with the average value of47.92%.The order of polymorphism percentage(PPB)from big to small was: Laoshan 49>Pingdu 51>Mount Kunyu 54>Feixian 45>Shiliu yuan 7>Hongmen 5>Haiyang 55>Sanyan temple 26>Zoucheng 47>Yiyuan 44>Seismic station 9>Puzhao temple 11.4.The genetic structure of Q.variabilis showed: Gst was 0.2671 and Nm was 1.3860.They all indicated that genetic variation was mainly within the populations,however there was a certain gene exchange between different families.Genetic identity ranged from 0.9178 to 0.9857 with the mean value of 0.9461.Genetic distance changed from 0.0144 to 0.0861 with the average percentage of 0.0509,the genetic similarity coefficient was high between different families.All of the 12 half-sib families were clustered into 4 groups at 0.044,and Metal test showed that there was no dependence relationship between the genetic distance and geographic origin in Q.variabilis(r=0.1287,p=0.8428).5.The fast-growing of Q.acutissima family selection showed: we tested that the characteristics of 1-year old,5-year old and 8-year old of Q.acutissima.The results exhibited that the fast-growing families from Huangdao of the 27 Q.acutissima half-sib families through the determination and analysis by statistical software SAS 9.2.In general,fourfamilies were selected: Sangyang temple 24(SY24),Sangyang temple 29(SY29),mount Culai 46(CL46)and Laiyang 52(LY52).6.The fast-growing of Q.variabilis family selection showed: we measured the indexes of 1-year old,5-year old and 8-year old of Q.variabilis,and tested through the determination and analysis by the using of statistical software SAS 9.2.The results showed that the fast-growing families of the 19 Q.variabilis half-sib families were selected from Huangdao.In general,three families were selected:Shiliu yuan 23(SL23),Shiliu yuan 35(SL35)and Seismic station 37(DZ37).