【作者】 郄丽娟；

【导师】 申书兴；

【作者基本信息】 河北农业大学 ， 蔬菜学， 2007， 硕士

【摘要】 大白菜(Brassica campestris L.ssp.pekinensis)和结球甘蓝(Brassica oleracea var.capitata L)是芸薹属作物中广泛种植的蔬菜，同时也是我国重要的农业资源。本研究以二倍体大白菜(AA，2n=2x=20)、二倍体结球甘蓝(CC，2n=2x=18)及其三个初级三体、四倍体结球甘蓝(CCCC，2n=4x=36)和二倍体大白菜种间杂交获得的异源三倍体杂种(ACC，2n=3x=28)为材料，利用间期核和中期染色体荧光原位杂交(FISH)技术，分析重复序列25S rDNA在大白菜和结球甘蓝的分布特点，准确识别了A、C基因组的染色体。并分别以大白菜基因组总DNA和结球甘蓝基因组总DNA为探针，对二倍体大白菜、二倍体结球甘蓝和异源三倍体进行基因组原位杂交(GISH)，分析杂交信号特点，探讨A基因组和C基因组的亲缘关系。研究结果如下：1.25S rDNA在大白菜基因组中存在着10个25S rDNA杂交信号，它们分别位于1号长臂近中部，2号、3号和4号长臂靠近着丝点的位置，10号染色体的随体上，杂交信号在不同染色体上的荧光强度强弱不同。2.25S rDNA在结球甘蓝染色体上检出了4个杂交信号，它们分别位于3号染色体短臂末端和9号染色体的随体上；在Triplo4、Triplo5和Triplo6三个甘蓝初级三体上也都检出了4个信号，信号所属的染色体和在染色体上分布的位置与二倍体相同。3.25S rDNA在异源三倍体间期核上检出了9个杂交信号，中期染色体上检出了8个杂交信号。根据信号的位置可知，它们分别位于结球甘蓝的3号染色体短臂的末端和9号染色体的随体上，以及大白菜的2号、3号和4号染色体的长臂靠近着丝点的位置和10号染色体的随体上，不同染色体上的杂交信号强弱不同。4.分别以大白菜的基因组总DNA和结球甘蓝的基因组总DNA为探针与大白菜和结球甘蓝杂交，所有染色体上均有杂交信号，但是A、C基因组染色体间的杂交信号特征不同。5.大白菜的基因组总DNA为探针在异源三倍体杂种染色体上杂交。无封阻时，28条染色体上都有清晰而强烈的杂交信号，但A、C基因组染色体间的杂交信号的特征不同；封阻适当时，有18条染色体上的信号十分微弱，其余10条染色体上的信号明显可见，能在一定程度上区分大白菜与结球甘蓝的染色体；封阻过度时，所有的染色体杂交信号都十分微弱，难以区分。6.结球甘蓝的基因组总DNA为探针在异源三倍体杂种染色体上杂交。无封阻时，所有染色体上都有清晰而强烈的杂交信号，但A、C基因组染色体上的杂交信号能明确区分；封阻适当时，有18条染色体上有强烈的杂交信号，其余10条染色体上的信号十分微弱，在一定程度上能区分大白菜和结球甘蓝的染色体；过度封阻时，所有的杂交信号都十分微弱，难以区分。更多还原

【Abstract】 Chinese cabbage(Brassica campestris L. ssp. pekinensis ssn rapa)and cabbage(Brassica oleracea var. capitata L.)were vegetables grown extensively in Brassica, were important agriculture resource in our country. In this research, with the diploid of Chinese cabbage(AA, 2n=2x=20), the diploid(CC, 2n=2x=18)and three primary trisomics self-established of cabbage, allotriploid hybrid(ACC, 2n=3x=28)in Chinese cabbage and cabbage as materials, the distributing trait of 25S rDNA repeat sequence in chromosomes of Chinese cabbage and cabbage were analyzed, chromosomes were identified exactly, by FISH technique on metaphase and interphase. With Chinese cabbage genome and cabbage genome as probes respectively, GISH was made to analyse the signal trait, so as to discuss the relationship between A-genome and C-genome in the diploid of Chinese cabbage, the diploid of cabbage and allotriploid hybrid in Chinese cabbage and cabbage. The study results were as follows:1. The gene 25S rDNA was studied on diploid of Chinese cabbage using FISH. The result indicated that there were ten 25S rDNA signals in Chinese cabbage genome. They were located on the middle of long arm of chromosome 1, near the centromere of long arm of chromosome 2, 3 and 4, and on the satellite region of chromosome 10. The fluorescence intensity of hybridization signals was various on different chromosomes.2. 4 25S rDNA signals were detected on diploid of cabbage chromosome, they were located on the end of short arm of chromosome 3 and on the satellite region of chromosome 9; 4 25S rDNA signals were detected in Triplo4、Triplo5 and Triplo6, the chromosomes and the position that these signals were localized on were the same as on the diploid.3. 8 25S rDNA signals were detected in allotriploid hybrid in Chinese cabbage and cabbage. They were located on the end of short arm of chromosome 3 and on the satellite region of chromosome 9, near the centromere of long arm of chromosome 2,3 and 4 and on the satellite region of chromosome 10, The fluorescence intensity of hybridization signals was various on different chromosomes.4. The labeled genomic DNA of Chinese cabbage and cabbage were respectively hybridized to Chinese cabbage and cabbage, signals were detected on all chromosomes, but the fluorescence intensity of hybridization signals was various on different chromosomes.5. The labeled genomic DNA of Chinese cabbage was hybridized to allotriploid hybrid(ACC)in Chinese cabbage and cabbage. When blocking DNA was not used in GISH, clear and strong signals were detected on all chromosomes, the intensity of hybridization signals was various on different chromosomes; When blocking properly, weak signals were detected on 18 chromosomes, clear signals were detected in other 10 chromosomes, to certain extent, chromosomes of Chinese cabbage and cabbage could be discriminated; When blocking overly, all signals were very weak and could not be discriminated.6. The labeled genomic DNA of cabbage was hybridized to allotriploid hybrid(ACC)in Chinese cabbage and cabbage. When blocking DNA was not used in GISH, clear and strong signals were detected on all chromosomes, the intensity of hybridization signals was various on different chromosomes; When blocking properly, clear and strong signals were detected on 18 chromosomes, weak signals were detected in other 10 chromosomes, to certain extent, chromosomes of Chinese cabbage and cabbage could be discriminated; When blocking overly, all signals were very weak and could not be discriminated.更多还原