The Abduction And Indentification Of The Polyploid Varieties In Populus Yunnanensis

Populus yunnanensis Dode is one of the species in Section Tacamahaca of genusPopulus and is also called Yunnan poplar, white poplar or Dongchuan willow,etc. It’snative to southwest China and especially it’s also one of the rare and valuable poplarresources which are located in low latitude but high altitude areas in our country and evenall the whole world. The technology of polyploid breeding on Populus yunnanensis Dodefor genetic improvement could offer to improve forest species with rapid growth and highquality, and thus it’s very important for economic development and ecologicalenvironment improvement. However, the foreign and domestic studies on polyploidbreeding of poplar almost focused on the species in Section Leuce Duby and SectionAigeiros. The emphasis on Populus yunnanensis Dode was far from enough, and for this,the petiole of Populus yunnanensis Dode was chosed as our experiment material and theTissue Culture Technology was used in the study. Main operations included the inductionof isolated polyploidy resources, identification, regeneration culture, optimization of theregeneration system and preservation of the materials with polypioid. The results of ourstudy were as follows:1. The medium of Populus yunnanensis polyploid induction adopted MS+0.5mg/L6-BA+0.05mg/L NAA+preincubation5d+40mg/L colchicine treatment2d, received51%of the variance.2. The rooting medium of Populus yunnanensis polyploid used MS+0.1mg/L IBA+0.1mg/L NAA+sugar30g/L+activated charcoal30g/L was appropriate, the ratio ofrooting got90%and haved many root hair, and kept good condition of growth.3.The research of Populus yunnanensis of morphology and anatomy have showed that theblade length and width of chimeras and tetraploid were greater than the diploid; thenumber of stomata was less obviously than the diploid, its volume was larger than thediploid; the leaf thickness and palisade tissue thickness of Populus yunnanensis chimerasand tetrapolid both higher than the diploid, and the content of chlorophyll was higher.4. The result of the ratio of photosynthesis showed that the net photosynthesis ratio ofPopulus yunnanensis chimeras and tetraploid was faster than the diploid, stomatalconductance, transpiration rate and diploid little difference, intercellular CO2concentrationin the diurnal variation of the process did not change significantly. 5. The Cytological Study of Populus yunnanensis showed that the apical material saturatedat0℃solution of p-dichlorobenzene (a mixture of ice and water) under the conditions ofpretreatment1H Carnot’s fixative, the fixed materials for1h at0℃(ice-water mixture).Concentrated hydrochloric acid:anhydrous ethanol=1:1solution from liquid at roomtemperature dissociation18min, with conventional knock-chip method, got a goodchromosomes of diploid chromosome number of2n=2x=38, tetraploid chromosomenumberfor2n=4X=76; in the same apical found38chromosomes cells and chromosome76cells.6.Observed the growth of Populus yunnanensis on the height and diameter growth ofdiamond-shaped leaves polyploidy plants (chimera) and round-leaf of polyploidy plants(tetraploid), they were all higher than the diploid.