Populus Deltoides Phenolic Glycosides Of Secondary Metabolites And Insect-resistant Trait Gene Mapping

Asian long-horned beetle (ALB) (ColeoPtera: Anoplophora glabripennisMotsch.) is the most harmful and widely dispersed pest to Chinese poplar trees.A BC1 population derived from a artificially selected elite clone "Populusdeltoides Bartr. CL. 'Nankang1'" with borer properties back-cross with its maleparent as materials, by using the methods of bioassay and quantitative trait locus(QTLs), the chemical plant defense mechanism was studied in the erperiment.The beetle can oviposite on many trees from different poplar species andcultivars, the hatching and surval rates often vary on trees. The period fromeggs to three-instar is critical for larval survival, therefore it is during thisstage that some substance is suspected of having an adverse effect on young larvaein the bark. According to the results of foreigners, the secondary metabolites ofPopulus species are dominated by phenolic glycosides (PG), and it had been provedthat PG had adverse effect on the growth of same Lepidoptera and Coleoptera insects.So we suspect that these compounds in the bark possess similar affect on the ALByoung larvae, there are no previous reports on this issue.By using high performance liquid chromatography (HPLC) combined withthin-layer chromatography (TLC), three PG: salicin, salicortin and deltoidin weredetected in the bark of P. deltioides Five kinds of PG were detected in the leaves,which included tmuloidin and tramulacin besides the three PG. Another transpgrentcrystal was got during fraction, which was proved a new compound identified by X-ray.In vivo bioassay test was carried out on ALB larvae with cmpounds in vitroat first time. After successfully extraction and separation the three PG, thebioassay on larvae was carried out by artificial feeding method. The bioassay resultshowed the three kinds of PG tested could prolong the duration of larval stadium.Salicortin and deltoidin could reduce the survival rate of lareae, pupate rate andgrowth weight evidently, especially for salicortin at high lever (more than 2%).By using HPLC method, the concentration of PG were determined for the barkof all trees of the back-cross population, and the concentration for three PG showcontinuous variation in the population, and the wound-induce for increasing effectis evident especially for salicortin.After artificial inoculation of Anoplophora glabripennis with cages makingon the trunk, insect resistance trait for every trees were assessed, and we sawthe variation for the resistance at POPll1ation1eve1. The ro concenttalion weredetermined in the organization around the nick, and the resu1t confimed thatvariabi1ity of 1arva1 perfomance on different individua1s of poP1ar Inay be part1yexp1ained by the variation in the concentration of ro ny different trees.As other traits, traits for PToducing of secontw metabo1ites as wel1 asinsect resistance are Under genetic contro1. The traits showed continuous variationuowing to PO1ygenetic inheritance and the inf1uence of enviroamta1 factors. Inthe opt, mptitative g6neticists used bionetrical metheds such as means andvariances to estiate Heters of gene action for mptitative tThits. A1imitation of these methOds is that they dO not yield infmtion on ggnes assePgrate entities but on1y on the sum of their effects. In recent years, a11 kindsof DNA Inarkers and gthetic 1inkage InaPs have becme poweffo1 tools for studyingignrtant bio1ogica1 Phenmeng eSPecia11y mptitative traits.By using AFLP (mp1ified fraseent 1eng'th PO1wtiams) markers, we talconstructed an integrated genetic InaP of the Ptwus de1to1deS back--crsspoPu1ation By using the metheds of analysis of variance wt and intervalInaPPing (IM, we W both concentrations of K and insect resistance index. 0neops affecting constitUtive sa1icortin, indued salicortin and insect resistanCeindex was detected on 1inkag grou 12 betWeen W59 and CAA/Mi176 eders,and 16. % l8. 7% and 19. ds of variation exPlained fOr three traits. T...