Identification Of Hybrid Progeny Of Tree Peony By SSR And Morphology

Tree peony,as one of Chinese top ten flowers,has high ornamental and economic value.Crossbreeding is the primary method to produce new varieties of peony.The breeding has expatiatory procedures including pollination,seed collection,planting,flowering,stable traits,selection,naming,declaration,and final promotion,which at least about 10 years.However,artificial hybridization for peony often produces a lot of pseudo-hybrid offspring,which may extend the breeding cycle and then waste masses of manpower and resources.Therefore,it is necessary to identify the authenticity of hybrid offspring in the early breeding.This study aimed to explore molecular markers of SSR and morphological markers for hybrids identification of tree peony.The experiments also expected to establish an identification method which would accelerate the breeding procedure and broaden the application of SSR molecular markers in peony's hybrids breeding.Sixty-nine hybrids from nine parents were used in this study: 'Hai Huang' × Paeonia lutea,'Fen Lan Pan' × P.lutea,'Bai He Wo Xue' ×P.lutea,'Hua Hu Die' × yellow peony,'Mo Chi Zheng Hui' × P.lutea,'Guan Shi Mo Yu' × P.lutea,'Feng Dan' × Paeonia lutea,'Bai Hua Cong Xiao' ×P.lutea and' Hai Huang ' × ''Bai He Wo Xue';the nine parents were also used in this experiment.These materials were cultivated in the experimental field of Chinese Academy of Forestry.The experiments and main results are as follows:(1)Flower type,color,faceplate,carpel,flower size,petal shape,leaf shape,leaf color,leaf,and petiole length were selected as the morphological markers.According to the specific phenotypic characters of parents,'progeny A-1','progeny C-1','progeny G-14',and 'progeny G-22' were preliminary identified as hybrids.The five indicators including flower type,faceplate,color,and leaf shape,were valuable references in hybrids identification.(2)Six pairs of SSR primers were screened from 47 pairs which were selected from published primers or designed by this study.Primers of M1,M15,and M29 can produce clear and stable microsatellite DNA bands.Based on the polymorphism of amplification bands,'progeny A-1','progeny C-1',and 'progeny G-22' were identified as hybrids and 'progeny G-14' was false hybrids.In summary,this study carried out identification of hybrids through the morphological and SSR molecular markers.The two methods produced relatively consistent results,and the latter was more robust.The present study indicated the combination of the two methods might be conductive to identification of the peony hybrids.