Study On The Restoration Of Brassica Napus OguCMS

Ad-6(F5) which were selectd by Lixufeng through distant crossing between B.napus and R.Sativus var.raphanistroides could restore B.napus OguCMS.This thesis reported the study on the field breeding, mophological characteristics,the factors affecting high frequencial shoot regeneration from hypocotyl explants ,protoplast cuture of progenies of Ad-6(F5),The results were as follows:1.The morphological characteristics of the progenies of Ad-6(F5)in successive test-cross with B.napus OguCMS, the setting percentage of progenies of Ad-6(Fs) became low gradually. These progenies sepregated complicately,which showed the main tendency that the economic and morphological characteristics of B.napus and good ability to restore B. napus OguCMS could not be gain in the same time . It seems that it is impossible to gain restorer with good setting pecentage and economic and morphological characteristics of B.napus by common methods.furthermore,compared with the contrast, there was no visible change in setting percentage of the progenies whose cytoplasm were replaced by common cytoplasm of B.napus.2. The study on the factors affecting high frequencial shoot regeneration from hypocotyl explants of TCF2TRTCDuring the process of breeding of the OguCMS restoreing line ,it often happened that the poor seed set and incompletely devoloped seeds lead to too limited restoring population,which was disadvantageous to the further research.In order to preserve the restorer and to increase the restoring population,we studied on the the factors such as preculture,hormone and AgNO, which affect high frequencial shootregeneration from hypocotyl explants of TCF2TRTC, The result showed that the best medium is MS+6-BA2mg/L+NAA0.5mg/L+5mg/LAgN03,which provided us the basis to select the restorer further.3. The study on the meiosis behaviors TCF2TR and TCF2TRTCThe meiosis behaviors of TCF2TR and TCF2TRTC were complicated..In diakinasis and metaphase I ,the chromosomal pair was irregular,the ratio of univalents and multivalents was high,the mean bivalent number showed a tendency of increasing ,There were still lagging chromosomes and chromosomal bridges in metaphase I and anaphase I . There was much dipolar segration and lagging chromosomes in Anaphase II .in tetrad period,the ratio of common tetrad was low,at the same time ,the ratio of diads was high.4. protoplast culture of F3(TC1)In order to break the limitation of common breeding methods,we had a try on protoplast culture of F,(TC1) ,so as to provide a basis for protoplast fusion, the result showed that in process when protoplast was isolated from hypocotyl of F,(TC,),the best combination of the enzyme solution was 2% Cellulase Onozuka R-10 +0.5% Macerozyne R-10,the highest yield of protoplast could reach about 1.6× 106/gFW. when protoplast were cultured in liquid medium,the best osmotic stabilizer was 0.6mol/L glucose,the best density of protoplast culture was 1.0×10Vml,The first cell divison occurred within 1-6 days and the highest division rate was about 38%.twenty days later ,a great munber of cell colonies and microcalli could be observed.