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61.
通过细胞学和分子标记技术对切花菊‘长紫’辐照后代进行分析,探讨辐射诱变机理,为菊花辐射育种提供理论依据。结果发现,辐照后代在减数分裂后期Ⅰ和后期Ⅱ出现落后染色体和染色体桥的异常率明显高于空白对照,且随着剂量升高异常率增加,两种异常现象发生的最高比率后期Ⅰ分别为9.0%和11.3%,后期Ⅱ为15.5%和8.6%。用21个ISSR引物扩增得到多态性条带112条,多态性比率71.3%,表明DNA在不同程度上发生了变异。通过UPGMA法将它们分为5类,聚类结果基本上与花型和花色的变异类型相关。 相似文献
62.
Adhesions between different cells and extracellular matrix have been studied extensively in vitro, but little is known about their functions in testicular tissue counterparts. Spermatogonia and their companion somatic cells maintain a close association throughout spermatogenesis and this association is necessary for normal spermatogenesis. In order to keep the relative integrity of the testicular tissues, and to detect the development in vitro, culture testicular tissues in a three- dimensional (3D) agarose matrix was examined. Testicular tissues isolated from 6.5 d postpartum (dpp) mouse were cultured on the top of the matrix for 26 d with a medium height up to 4/5 of the 3D agarose matrix. The results showed that in this 3D culture environment, each type of testicular cells kept the same structure, localization and function as in vivo and might be more biologically relevant to living organisms. After culture, germ cell marker VASA and meiosis markers DAZL and SCP3 showed typical positive analysed by immunofluorescence staining and RT-PCR. It demonstrated that this 3D culture system was able to maintain the number of germ cells and promote the meiosis initiation of male germ cells. 相似文献
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本文以幼穗为材料,观察了二棱大麦花粉母细胞的减数分裂。观察表明:大麦的小穗顺序与花粉母细胞减数分裂时期呈显著的相关关系。同一小花不同花药减数分裂时期基本是同步的;同一花药细胞减数分裂不同步的比率为50%。实验也统计了减数分裂各时期在同一穗上的频率。观察到大麦花粉母细胞减数分裂各时期均有体细胞有丝分裂现象;也观察到第二次减数分裂子细胞分裂不同步的不正常现象。 相似文献
66.
Summary F1 hybrids of triazine resistant Brassica napus and triazine susceptible B. oleracea were morphologically intermediate to the parent species. Of 49 hybrids examined, 44 had 28 chromosomes, two had 37, one had 38 and two had 56. The 38-chromosome plant was thought to be a matromorph, the others, A1C1C (28), A1C1CC (37) or A1A1C1C1CC (56) type hybrids. Pollen stainability averaged 9.0% in the sesquidiploid, 32.0% in the tetraploids and 89.5% in the hexaploids. All the interspecific hybrids were resistant to 1.0×10-4 mol L-1 atrazine. The sesquidiploid hybrids produced gametes with chromosome numbers ranging from 9 to 17 and the tetraploid hybrid gametes had chromosome numbers from 15 to 22. Most hybrids produced self-seed. The partial fertility of these hybrids may permit their backcrossing to one or both parents. 相似文献
67.
三个药用菊品种的细胞学研究 总被引:12,自引:5,他引:12
对原产中国的3个药用菊品种-抗白菊,滁菊,怀菊的核型及减数分裂进行了研究,结果表明,抗白菊2n=4x=36=2M+18m+16sm(2SAT)减粉分裂中期I(MI)平均每个芬粉母细胞(PMC)有0.20I+17.70Ⅱ+0.10Ⅳ,滁菊2n=6x=54=24m(2SAT)+22sm+6st+2t,在MI平均每个PMC有0.44I+26.66Ⅱ+0.06Ⅳ,怀菊2n=6x+1=55=6M+26m+1 相似文献
68.
Three tetraploid (2n= 4x= 28) wheat Triticum turgidum L. landrace morphotypes (= genotypes) from Ethiopia were found to carry a variant karyotype directly discernible under the microscope. This was possible because the rearrangement involved one of the satellited chromosomes. Giemsa C-banding revealed that the rearrangement resulted from a 5BS.6BS(5BL.6BL) centric reciprocal translation. The banding pattern on 5BL was polymorphic, suggesting that this translocation might have occurred more than once. There was little C-band polymorphism for the remaining chromosomes, except for 2A. As pure lines, all three morphotypes showed normal chromosome pairing at metaphase I (MI) in pollen mother cells (PMCs). indicating that they are genomically stable. Meiotic analyses of F1 hybrids and F2 segregates derived from crosses with tester varieties clearly indicated that one of them (B-l–9) carried another translocation. However, we were not successful in delecting the chromosomes involved, presumably the interchanged segments did nol include C-banding regions. By using T5BS.6BS, direct evidence for segregation distortion against translocation homozygotes in intervarietal hybrids was obtained. The distorted segregation was attributed lo zygotic selection. No aneuploid plants were obtained from the F2 segregates. However, translocation heterozygotes resulting in unstable meiosis were abundant in the F2 generation. The implications of the results in using the indigenous landraces in hybridization breeding are discussed. 相似文献
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为研究同源多倍化对拟南芥减数分裂前期Ⅰ过程的影响,以哥伦比亚生态型(Columbia)二倍体拟南芥为试验材料,经0.2%秋水仙素加倍处理,利用流式细胞仪和细胞学方法鉴定倍性,获得同源多倍体拟南芥;分析同源多倍体拟南芥的形态特征,利用荧光显微观察不同倍性拟南芥的减数分裂前期Ⅰ过程,并利用荧光定量PCR技术分析与减数分裂前期Ⅰ过程相关的基因的表达变化。结果表明,与二倍体拟南芥相比,在细胞学水平上,不同倍性拟南芥的减数分裂过程基本一致;在分子水平上,多倍化对拟南芥减数分裂产生一定影响,同源重组相关基因的表达量呈现上调或下调的变化,且功能相关或有相互作用关系的基因的表达量变化趋势相似。 相似文献