Study On Inducing Technology Of Poupulus Ussuriensis Kom. Triploid

Poupulus ussuriensis Kom. is indigene trees of northeast forest section in our countrywith fast growth and easy production. Poupulus ussuriensis Kom.branches were collected fromMao'er moutain, Wei fiver and Dailing in 05,06,07. These male and female flower budswere treated directly to induce 2n pollens and megagametophytes with colchicines ormegagametophytes after pollination were treated by colchicines to study triploid breeding.Finally we got seeds of 4719 grains and seedlings of 539. The progeny that we got throughexperiments were identified in exterior appearance and the number of chromosomes. Theresults were followed:(1) The sporocytes of Populus ussuriensis Kom. need for 120h to complete meiosis under10～20℃of greenhouse temperature. Male flower buds started expanding, crazing,revealing anthotaxy, but there is no change in exterior appearance except obviouscolour change of semets, from viridescence to dark red.Exterior appearance of male flower buds had no change when pollen mother cells hadentered leptotene stage after water cultured for 42h. In this period chromosomes coagulatedspindly linear structure from chromatin and there were big karyon,evident nucleolus,unorderly chromosomes. After 30h, most pollen mother cells grow to pachynema andhomologues start synapsis to bivalent. Chromosomes got to the two poles when male flowerbuds were cultured for 120h in water. Nucleolus substance got together to form 4 daughternuclides. This was quadrant phase. During the whole meiosis of Populus ussuriensis Kom.,lots of parallel and vertical spindle in metakinesis and maybe the angle of spindle is relate toproducing big pollens.(2) Usually the pollen grains diameter of Populus ussuriensis Kom is from 15μm to 30μm.So we classify the pollen grains diameter of d＜25μm and 25μm＜d＜37.5 as small pollen and37.5μm＜d＜50μm and d＞50μm as big pollen. Male branches ofPopulus ussuriensis Komwere induced using orthogonal experiment of three factors and levels, the results werepresented: The time of cultured in water has extremely significant to A1 and A3 pollenspercentage, just as treating ways to A3 pollens and colchicines concentration to A2 pollens.Each factor has not extremely remarkable effect to A4 pollens but variance influence.The bestcombination of inducing A3 pollens is male flower buds cultured 4 days and injecting 0.3%colchicines.(3) This experiment used two ways to induce 2n female gametes. The first way is crossdesign of three factors and three levels. These are timeofcultured(2d,4d and 6d),means ofcolchicines(injecting,soaking24h and soaking 36h) and concentration of colchicines(0.25%, 0.5% and 0.75%). The effect of injecting is better than soaking with bottles and gets moreanthotaxy.There are high anthotaxy surviving percentage and seed gaining percentage in thesecond way(treating 12,24,36h with 0.5% colchicine after pollination 14,24,36h). Allthe treatments got seeds of 4719 and seedlings of 539 except 3#. Appearance identification wasperformed the measure of the height,sowneck,length,width and leafstalk of the third leaf.The average height of 9# is the best (33.9cm) and the order of height is 6#,5#,8#,7#,ck,1#,2#,4# through comparison on significances. Ck expresses excellently and allthe treatments are good in multiple comparison of the length of the third leaf. The averagevalue of the leafstalk of the third leaf of 1# is the best(0.80cm) and 4#,8#,ck,7#,6#,9#,2#,5# in turn.The time of beginning treatment after pollination had significant influence to the heightand length of the progeny. The lasting time of colchicines treatment has the best significantinfluence difference to the height,sowneck,length of progeny and has no significantinfluence to the width of leave. The variance amplitude of the height,sowneck and length isthe best when 24h after pollination began to induce and induced 12h using colchicines. So thetreatment effect is perfect when 24h after pollinating female buds began to induce and last 12h.The most reliable way to judge if it is multiploid is to identify the number ofchromosomes in pollen mother cells and root tip cells. Progeny individual plants obtainingthrough treating were identified in the number of chromosomes. 4# treatment is found there are57 chromosomes in 70 progeny individual plants.