Exploration On Phylogenetic Relationships And Breeding And Propagation Of Generalized Sedum

There existed abundant wild plant resources in China,but few with great characterswere konwn by people.It was of huge significance to investigate and collect species andclassify them. Crassulaceae had the same problem.In the process of application,manydifficulties were caused because of the confusion between species and cultivars.Thisphonomenon also extremely affected the protection of germlasm and creation of newcultivars.Therefore,wild species and part of cultivars were collected in Beijing, Liaoning,Shanghai, Sichuan, Hangzhou, Guangzhou.All the collections were introduced to thenursery of Beijing to lay foundations of developing the resourses.First, DNA plant genelibrary was built and clustering features were analysed by DNA barcoding.Second,Hylotelephium spectabile was selected as a sample to discuss its breedingsystem.Last,tentative propagation technique was studied.The main results were as follows:(1) The research conducting in this article contained32samples (Sedum,Hylotelephium, Orostachys),5of which stayed unidengtified. Genome DNA wasextracted by modified CTAB method, nuclear DNA ITS and chloroplast psbA-trnH wasseprated with PCR.Manually processed, Composition and the inter-and intraspecificgenetic distances were calculated. Then phylogenetic trees were built based on theNeighbour joining method.The results indicated32accessions divided into4branchs:Sedum,Phedimus,Hylotelephium,Pseudosedum. In the branch of Sedum, there appeareda complex branches under the genus.Orostachys and Hylotelephium clustered in onebranch.The unkown species were close to their species,and well identified. X27-X31wereSedum trullipetalum,Sedum alfredii, Orostachys aliciae, Sedum emarginatum,Sedummakinoi.X32was mixed and stayed unidentified.(2) flowering investigation, shape measuring, pollination characteristics analysis,out-crossing index estimating and artificial pollination experiments were conducted on theHylotelephium spectabile to establish the breeding system. The main results were asfollows:in the natural condition of Beijing, the group flowering stage was about47daysfrom August to October and the majority kept full blooming between4thto22ndinseptember2013about18days, meanwhile the life span of single flower remained 9-14days.During the whole flowering process, pollen viability reached97.6%, and kept ata high activiy after the first several days; however,the stigma became muture beforeanthers and reached highest receptivity in the2days, then decreased to zero. The OCIindex was4, this bisexual flower was mainly outcrossing, partly self-crossing andpollinators needed flower. Seed germination characteristics indicated Hylotelephiumspectabile was typical photophil seed. Under room temperature and enough watercondition, full light accelerated germination of the seeds.Heat shock greatly influenced itsgermination.The best treatment was30℃and presoaking13h.(3) Asexual propagation for generalized Sedum was studied, and Sedum‘Matrona’waschosen as representative.Young leaves were selected as explants.The best culture mediumfor callus induction was MS+1mg·L-12,4-D+0.5mg·L-1TDZ+0.5mg·L-16-BA, with theinductive rate of94.44%.In this culture medium, there formed a lot of loose, granularembryogenic callus.