The Study On Anther Culture And Polyploid Induction Of Pear

During this study,on one hand,we take four cultivars of"Dangshansu pear","Zaosuhongpear","Longyuanyang pear"and "Liuyuesu pear" as the experimental material, A series offactors that affecting anther culture were discussed,such as genotypes, inoculation period, thepretreatment time and manner of composition of media,on the other hand,we take the speciesof"Dangshan pear","Zaosuhong pear","Kuerle pear","Zaosupear"and"9712"as the experientalmaterial,and on the basis of establishing its regeneration system, use of colchicine to inducepolyploid,the following is the main test results we carried out:1.Anther culture(1) Suitable for the developmental stages of microspore of anther culture is Mononuclearaside period,with callus induction rate of26.0%, the rate of early mononuclear periodand thelate mononuclear period is11.49%and7.58%.(2) The suitable explant disinfection method for anther is: use75%ethanol treat with25splus0.1%mercuric chloride treat with l0min, in this approach, the callus induction rate canreach36%.(3) The suitable for low temperature pretreatment days are3d, this processing time, thecallus induction rate of up to32.45%.(4) The suitable basic medium type is MS medium, and MS medium conditions, thecallus close texture, showing more yellow-green, and the proliferation of faster and lessbrowning.1/4MS and1/2MS culture conditions, the callus loose texture and growth rate isslow and some browning.Callus began to form as a matter of time sequence:MS>1/2MS>1/4MS.(5) The effect of Solid culture, is significantly better than the liquid medium.(6) The early stage of the anther culture,take dark for processing will be greatly enhancedcallus induction rate.(7) IAA0.5mg/L+6-BA2.0mg/L+2,4-D1.0mg/L is the suitable harmone concentrationsof anther culture, with the induction rate of26.76%.2.In the process ofestablishment of pear in vitro micropropagation system, the outcome asfollows:(1) MS+1.0mg/L6-BA+0.3mg/LIBA is the the suitable,its treatment plant multiplicationcoefficient up to3.86, and grow best, less callus.Induction and proliferation factor of three species from high to low:"Dangshan Pear">"Kuerle Pear">"zaosuhong pear".We also foundthat, with6-BA concentration increased, the budding required number of days also showed adecreasing trend.In conditions of low concentrations of6-BA, tissue culture and plant type,fast growth, but the multiplication coefficient is small, while high concentrations of6-BA,plant multiplication coefficient is higher, but its growing poor, and easy to form a callus.(2) Medium hormone concentrations to0.3mg/LNAA, The highest rooting rate can reach52.4%, and the root growing thick, but the average rooting2.48isnot the highest, when thehormone concentration of0.5mg/LNAA, the average root number to the highest, but thegrowing but not as good as the former.3.Polyploid induction(1)0.02%concentration,treat for24h is most appropriate combination of Colchicineimpregnation to induced polyploidy,under this condition, zaosuhong pear survival rate of93.3%, while the induction rate was13.3%,"Kuerle Pear" survival was96.7%, the inductionrate was16.7%.(2) Leaves induced by the mixed culture, the leaves attached colchicine concentration of25mg/L medium, the variation rate is the highest,"Kuerle pear" is13.3%,"zaosuhong pear"10%, while comparison of results, regardless of the mutation rate or the tolerance ofcolchicine, are the KuerlePear> zaosuhong pear.(3) Using colchicine mixed culture method, stem segment as the materials, The highestmutation rate of50mg/L colchicine concentration can be achieved by16.7%, and the effect isbetter than leave culture, at the same time, the mortality rate is also much lower than leafculture.(4) The leaf length, leaf width, leaf thickness and other characteristics of the variation ofplants than diploid plants have significantly longer, wider and thickening about "KuerlePear"and "zaosuhong pear",and "Kuerle Pear" tetraploid leaves relatively larger than"zaosuhong pear".(5)"Kuerle Pear" and "zaosuhong pear" diploid and tetraploid in guard cell length,stomatal length, stomatal density are obvious different in the width of the tetraploid guardcells are slightly wider than the diploid, and two varieties guard cells and stomata length oftetraploids were significantly greater than the diploid.