【作者】 耿霄；

【导师】 申书兴； 马德伟；

【作者基本信息】 河北农业大学 ， 蔬菜学， 2003， 硕士

【摘要】 本文以大白菜同源四倍体小孢子培养产生的且已鉴定为三体的2号、7号、9号、10号非整倍体植株为试材，针对各类三体间n+1雄配子传递率差异问题，对三体大白菜花粉母细胞的减数分裂行为、花粉发育的组织切片观察、花粉特征特性及生理生化等方面进行观察研究，同时就不同三体的额外染色体附加效应对减数分裂过程中染色体的行为、花粉活力、结子率、n+1雄配子传递率的影响进行分析。研究结果如下： 1．以2号、7号、9号、10号三体为父本，二倍体为母本进行杂交后的结子率分别为50.35％，36.90％，17.91％，0，n+1雄配子传递率分别为7.69％，3.57％，8.70％，0。 2．三体在减数分裂过程中出现异常现象。三体在终变期和中期Ⅰ，3个同源染色体联会成三价体，或2个联会成二价体和1个单价体，或3个都为单价体；后期Ⅰ出现落后染色体或单价体提前分离，导致除10-11式分离外，还有10-1-10，9-12，11-11，10-2-10，10-12，10-10，9-1-11等不均衡分离方式；后期Ⅱ有11-11-10-10，10-10-10-12，10-10-10-11，10-11-11-11，11-11-10-9，10-10-10-10，9-12-10-10，9-9-11-11，11-10-10-9，12-10-9-11，11-9-9-13，10-10-10-9等分离方式；4个三体中的n+1小孢子频率不同。这些现象均会不同程度的降低各个三体的传递率。 3．组织切片表明：2号、9号三体的花粉发育过程与二倍体相似，基本正常，7号、10号三体在减数分裂时期绒毡层出现过异常现象，但7号三体在以后的时期绒毡层则表现正常。而10号三体的绒毡层虽在四分体时期表现正常，但在小孢子时期又表现了异常，并且花粉全部败育。因此影响10号三体n+1雄配子传递率的主要原因就是花粉的败育。 4．2号三体的花粉整齐度与二倍体无显著性差异；7号、9号三体的花粉整齐度均极显著低于二倍体；9号三体的花粉整齐度最低；10号三体不散粉。花粉整齐度与结子率有极显著的正相关关系，因此，花粉整齐度可作为预测结子率的一个指标。 5．9号三体的花粉活力显著低于二倍体；2号、7号三体的花粉活力极显著低于二倍体；7号三体的花粉活力最低。三体的花粉活力与传递率呈显著的正相关关系。 6．2号、7号、9号三体n+1雄配子传递率与减数分裂过程中染色体的行为和花粉生活力的降低有关，同时，n+1雄配子受精能力、2n+1胚发育能力可能也会影响n＋l雄配子的传递率。由于每个三体的额外染色体所携带的遗传信息（基因）不同，导致这些因素发生不同程度的变化，最终导致不同三体MI雄配子的传递率产生差异。 7．4个三体的可溶性糖、淀粉及氨基酸含量均极显著低于二倍体。更多还原

【Abstract】 Trisomics 2.trisomics7.trisomics9 and trisomics 10 were experiment materials.which were cultured from microspore of homologous tetraploid of Chinese cabbage and had been appraised.To solve the problem of n+l male gamete transmission difference of distinct trisomics,meiosis behavior of pollen mother cell,tissue section observation of pollen development,pollen characteristic, physiology and biochemistry would have been studied.And it was analyzed that additional effects of extra chromosome of distinct trisomics influnced chromosome behavior at meiosis,pollen activity.seed set,n+l male gamete transmission.The results of study were as follows:1. Seed set was 50.35%,36.90%,17.90%,0 respectively after trisomics 2, trisomics 7,trisomics 9,trisomics 10 as male parent hybridized with diploid as female parent.N+1 male gamete transmission was 7.69%,3.57%,8.70%,0 respectively.2. There existed many abnormal phenomena during meiosis.Thress homologous chromosomes of trisomics associated as a trivalent or a bivalent and a univalent or three univalent during diakinesis and metaphase 1 ;Laggard chromosome and univalent separated in advance at anaphase I ,leading to distribution of 10-1-10,9-12,11-11,10-2-10,10-12,10-10,9-1-11 besides 10-ll;And there was distribution of 11-11-10-10, 10-10-10-12, 10-10-10-11, 10-11-11-11, 11-11-10-9, 10-10-10-10, 9-12-10-10, 9-9-11-11, 11-10-10-9, 12-10-9-11, 11-9-9-13, 10-10-10-9 at anaphase II ;n+l microspore frequency were different of four trisomics.These phenomna all reduced the transmission of each trisomic in various degree.3. Tissue section indicated:Pollen development courses of trisomics 2,trisomics 9 were normal basically.similarly to diploid.The tapetum cells oftrisomic 7 and 10 showed abnormal phenomenon at meiosis,but trisomic 7 recovered normality at other periods.Although the tapetum cell of trisomic 10 was normal at the stage of tetrad,abnormal at the stage of microspore when pollen was all aborted,so pollen abortion was the main reason for influencing n+l male gamete transmission of trisomic 10.4. Pollen regularity of trisomic 2 had no significance difference with that of diploid;Pollen regularity of trisomic 7 and 9 was lower than that of diploid significantly;Pollen regularity of trisomic 7 was the lowest;Trisomic 10 didn’t scatter pollen.There was significantly positive correlation between pollen regularity and seed set,so the former could be regarded as an index predicting the latter.5. Pollen activity of trisomic 2,7,9 was lower than that of diploid significantly;Pollen activity of trisomic 7 was the lowest.Pollen activity had positive correlation with transmission rate significantly.6. N+l male gamete transmission of trisomic 2,7,9 had the relation with chromosome behavior at meiosis and with the degression of pollen activity.Besides,n+l male gamete fertilization ability and 2n+l embryo development ability perhaps could influnce it,too.Extra chromosome of each trisomc carried different heredity information(gene),leading to above factors changes in various degree /which caused n+l male gamete transmission difference of distinct trisomics.7. Soluble sugar,amylum and amino acid contents of four trisomics were lowe than that of diploid.更多还原