Research On Construction Of Ten Poplar Clones RSAP,CDDP,SSR Fingerprints

In order to breed new poplar varieties and identify the genetic relationship between the selected varieties,accelerate the pace of poplar clone breeding,promote the excavation of excellent poplar germplasm resources,promote the process of genetic improvement of poplar,and facilitate the popularization and planting of excellent poplar germplasm resources.In this experiment,the genetic diversity of 10 excellent poplar clones(qinbaiyang 1,qinbaiyang 3,qinbaiyang 5,84K,1-101,Xinjiang poplar,Populus tomentosa No.30,07-17-18,07-23-23,07-30-11)were analyzed by three molecular markers RSAP,CDDP and S SR.The polymorphism of the amplified products was analyzed by capillary electrophoresis,and the cluster analysis of the tested clones was conducted based on UPGMA.The fingerprint of 10 clones of poplar was constructed.Finally,the efficiency of three molecular markers was compared.It is beneficial to the study of genetic improvement of poplar and the development of the production and promotion of improved varieties.The conclusions are as follows:(1)Among the 36 pairs of RSAP primers,6 pairs were selected with excellent amplification effect.A total of 133 polymorphic loci were amplified,with an average of 22.17 loci per primer pair.The average Shannon information index was 0.326;the average Nei’s gene diversity index was 0.488,and the genetic similarity coefficient between clones was 0.400～0.817.Only two primer combinations,RS2/RS4 and RS2/Rs7,could identify all the te.sted clones,and each clone had its own unique map information.The results of cluster analysis showed that 10 poplar clones were divided into two groups,Xinjiang poplar and Populus tomentosa No.30 were clustered into one group,and the rest clones were clustered into another group,which was consistent with the actual genetic relationship.(2)8 polymorphic loci were amplified by 8 highly polymorphic CDDP primers,with an average of 10.75 loci per primer.The average Shannon information index and Nei’s gene diversity index were 0.468 and 0.303,respectively.The genetic similarity coefficient between clones was 0.410～0.774.The combination of primer MYB2 and primer ERF1 could identify all tested clones.At the genetic similarity coefficient of 0.510,the tested clones were divided into two groups.Xinjiang poplar and Populus tomentosa No.30 were divided into one group,and the rest clones were divided into another group,which was consistent with the biological classification.(3)7 pairs of SSR primers with high polymorphism were screened out from 20 pairs of SSR primers.A total of 41 polymorphic loci were amplified,with an average of 5.9 loci per primer pair.The average Shannon information index and Nei’s gene diversity index were 1.433 and 0,694,respectively.Primers PMGC-2020 and PMGC-2607 could distinguish all clones.Cluster analysis showed that the qinbaiyang series and 84K were clustered together,and the 07 series 1-101 were clustered together,which was consistent with the actual genetic relationship.(4)Comparing the PPB,PIC,MI,Rp and other indicators of the three molecular marker systems,the polymorphism,clustering results and marker efficiency of the three markers were analyzed.The highest PPB was SSR(100.00%),the highest PIC was RSAP(0.9542),the highest Rp was CDDP(18.82),and the highest MI was CDDP(1.07).According to PPB and PIC values,SSR markers had the highest information content,while RSAP markers had the highest polymorphism.In terms of MI and Rp,CDDP had the highest labeling efficiency and strong primer identification ability.RSAP and CDDP markers have certain applicability in the study of genetic diversity and genetic structure of poplar.