| There are abundant genetic resources of the armeniaca(Armeniaca Mill.or Prunus armeniaca L.)in Xinjiang.There exist many apricot types with huge variation,which plays an important role in the spread and domestication of apricot in the world.However,the genetic background of these local resources,classificationis,identification and phylogeny are not well understood.These would seriously hinder the protection,utilization and germplasm innovation.In this study,the plant resources of apricot were collected and classified,meanwhile the species identification and the phylogenetic relationship of armeniaca(subgenus)was reconstructed by DNA barcoding.Genetic diversity were evaluated based on SCoT molecular markers and RAD sequencing.Furthermore,Purple apricot(P.dasycarpa Ehrh.)origin and phylogeny were determined by DNA barcoding.Based on molecular biology,the genetic diversity,classification,identification and the phylogenetic of the origin were research.The main results are as follows: 1.A total of 228 bands were generated from 24 SCoT primers in 78 genotypes.The polymorphic rate of SCoT markers was 94.16%,and the average number of polymorphisms was 8.5.The result showed that the 78 genotypes could be divided into 3 Clusters,by using UPGMA and PCoA.The purple apricot could be seperated from the other apricots and the similar coefficient was about 0.62.The genetic diversity of apricot resources in Aksu area is the most abundant and also relatively old.Meanwhile,there were gene flow between germplasm from 4 regions.2.The phylogenetic relationships of armeniaca(subgenus)materials,based on the analysis of 38 sequences of ITS,matK,rbc L and psbA-trn H with the published previously 51 sequences were investigated.mat K,rbcL and psbA-trnH were not suitable to characterize armeniaca(subgenus),because the three chloroplast sequences were extremely conserved in armeniaca(subgenus),and the variation sites were rare.Two different ITS fragments were detected and could effectively distinguish and identify plum and P.dasycarpa Ehrh.from other armeniaca(subgenus)plants.3.Chloroplast rbc L?matK?trn H-trnK and nuclear gene ITS from 14 materials of 4 species.P.dasycarpa Ehrh.,P.armeniaca L.,P.cerasifera and P.salicina.were sequenced.We obtained the 58 sequences and found 13 specific variation sites in P.dasycarpa Ehrh.and P.cerasifera.Based on these sequences characteristic of nuclear and chloroplast gene,those evidence suggested P.dasycarpa Ehrh.might be a natural hybrid derived from female parent P.cerasifera.4.In this study,Hiseq2500 was used to conduct Paired-end sequencing,and the average depth of individual sequencing was 132 X,revealing the variation of 24 genotypes at the whole genome.The average number of unique tags was 53,170 and 35,157 genotyping SNP sites were obtained by using the 2b-RAD sequencing technique.Based on these variation sites,the similar phylogenetic tree were constructed by maximum likelihood method and adjacency method.In this topology,2 purple apricot(P.dasycarpa Ehrh.formed 1 branch,the approval rate is 100%,22 common apricots were clustered together,20 cultivated apricots in south xinjiang were separated into a subcluster,and 2 cultivated apricots in northwest China showed a far distance to them.This indicated an intraspecific variation occured,the common apricot in south Xinjiang and northwest China belong to the same species.P.dasycarpa Ehrh.is a different species from P.armeniaca L.based on genome data.In summary,moste cultivated apricots in southern Xinjiang are confirmed as P.armeniaca L or armeniaca,with lower intraspecific variation.However,P.dasycarpa Ehrh.should be generated from interspecific hybridization,with female parent P.cerasifera.Both ‘Zixing' and ‘Aliwala' are presented intermediate phenotypes or genotype.Therefore,P.dasycarpa Ehrh.could not be identified as independant species. |
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