【作者】 宋国立；

【导师】 王坤波；

【作者基本信息】 中国农业科学院 ， 作物遗传育种， 2007， 博士

【摘要】 棉花是我国乃至世界上最重要的纤维经济作物，阐明棉花的遗传进化和遗传亲缘关系，对于棉花遗传改良具有重要的理论和实践意义。本研究以16个棉种为材料进行荧光原位杂交分析，以明确其种间关系和起源与演化规律。主要研究结果如下：1以45S rDNA为探针，对二倍体棉种A、B、C、D、E、F、G等7个基因组共9个棉种FISH研究发现，除索马里棉有4个rDNA信号、长萼棉有2个rDNA信号、比克氏棉有8个rDNA信号外，其余二倍体棉种均有6个rDNA信号。明显看到亚洲棉有2个强的杂交信号位于染色体短臂的近端部，2个中等强度的杂交信号也位于染色体短臂的近端部，另外2个弱信号位于染色体短臂端部，而草棉的6个杂交信号中4个为中等强度的信号，2个为弱信号。三裂棉的6个45S rDNA杂交信号强度和大小几乎区别不大，并且全部位于染色体短臂的端部。值得注意的是在雷蒙德氏棉棉的6个rDNA杂交信号中，其中2个比较清楚的可以看到大的随体，rDNA杂交位点位于次缢痕处。在所有的以45SrDNA为探针的杂交中，长萼棉和比克氏棉是2个特殊的棉种，长萼棉的45S rDNA杂交信号最少，仅有2个，并且位于着次缢痕处，这一点不同于其他棉种，其他棉种的45S rDNA杂交信号位于染色体的端部或近端部；比克氏棉有8个45S rDNA杂交信号，其中2个强信号杂交位点位于染色体长臂的端部，这也是该棉种与其他棉种的不同之处。2在以自身基因组DNA为探针，自身染色体DNA为靶DNA的荧光原位杂交中。阿非利加棉和雷蒙德氏棉具有不同的结果。对于阿非利加棉而言，所有的染色体均有比较强的信号分布，但是也可以看出，这些信号主要分布在染色体中部，个别染色体上杂交信号仅仅在着丝粒上，而在染色体的端部却没有杂交信号。而对于雷蒙德氏棉而言，杂交信号要弱的多。3以TM—1染色体为靶DNA，以亚洲棉石系亚一号为探针，以雷蒙德氏棉封阻的结果，可以明显的看到26条红色的A染色体组和26条蓝色的D染色体组，直观地证实了陆地棉是一个双二倍体起源的棉种。以A基因组为探针、陆地棉染色体为靶DNA、鲑鱼精DNA封阻荧光原位杂交中，其中有2个强信号位于A亚基因组上，说明陆地棉的供体种是亚洲棉而非草棉。4以陆地棉染色体为靶DNA，以A基因组为探针，D基因组封阻看不到NOR，以陆地棉染色体为靶DNA，以D基因组为探针，A基因组封阻可以明显看到NOR，说明陆地棉的45S rDNA是由D基因组提供。5在所有以陆地棉染色体为靶DNA，以D基因组DNA为探针的杂交中，戴维逊氏棉为探针的杂交信号最强，说明陆地棉的D基因组供体种为戴维逊氏棉。6海岛棉具有6个NOR，其中2个在A亚染色体组上，4个在D亚染色体组上，并且海岛棉的NOR也是来自与D亚染色体组。7以海岛棉染色体为靶DNA、雷蒙德氏棉为探针的杂交中信号最强，说明海岛棉与雷蒙德氏棉的亲缘关系最近，雷蒙德氏棉为海岛棉D亚染色体的供体种。8以阿非利加棉基因组为探针，以黄褐棉基因组为靶DNA，用鲑鱼精DNA封阻的试验，黄褐棉的26个A亚基因组被染为红色，2个大的NOR位于A亚基因组上，但没有发现另外4个NOR位点。用黄褐棉基因组为靶DNA，以阿非利加棉基因组为探针，以戴维逊氏棉封阻时，也仅能看到2个NOR。而双色荧光原位杂交发现，黄褐棉的所有6个NOR都位于A基因组上。并且这些所有的45S rDNA所在位点已全部同步进化为A基因组的了。9瑟伯氏棉的基因组与黄褐棉的D亚基因组同源程度最高，推断瑟伯氏棉为黄褐棉D亚基因组的供体种更多还原

【Abstract】 The cotton is the most important fiber economic crop in the world. It is inportant to expound cotton orgin and evolution for the cotton heredity improvement. This research carries on the fluorescence in situ hybridization compartion of cotton eight genome species to clear about interspecies relationship and the origin and the evolution of the Gossypium. The main result are as follows:1. Gsomalense has 4 singnal of 45S rDNA, Glongicalyx has 2 signal, G.bickii has 8 signal, and G.herbaceum,G.arboreum, G.anomalum, G.austral, G.trilobum and G.raimondii have 6 signal. G.arboreum have 2 strong hybridization signal located in near end of chromosome short arm obviously, the medium hybridization signals in the near end of chromosome short arm, and 2 small hybridization signals in the end of chromosome short arm. G.trilobum has 6 the signal with the same size and strength located in the end of the chromosome short arm.It is noticeable that G.raimondii has 2 major satellites, and its 45S rDNA hybridization signal is located in secondary constriction. G.longicalys and G.bickii are the special species. The 45s rDNA hybridization signals are located in the secondary constriction for the G.longicalyx,and G.bickii has 2 45S rDNA located in the end of chromosome long arm.2. G.hebaceum has major singal taking its own gDNA(genomic DNA) as probe, but G.raimondii has minor signal taking its own gDNA as probe. all of the signal are located in the near centromere regions. and the single copy genes are located in the end of the chromosome.3. There are 26 red chromosome and 26 blue chromosome with the TM-1 chromosome as target DNA, G.arboreum gDNA as probe and G.raimondii as block DNA. It implies that G.hirsutum is a allotetroploid species, and G.arboreum is the diplod progenitor of A subgenome of the G.hirsutum4. rDNA from G.hirsutum has been homogenized to a D genome repeat type.5. G.davisonii is the diplod progenitor of D subgenome of the Ghirsutum6. G.barbadense has 6 NORs(nucleolar organizing regions), the 2 NORs of them are located in the A subgenome of the chromosome of G.barbadense, and the 4 NORs are loacatend in the D subgenome. The NOR of G.barbadense comes from D genome7. G.raimondii is the the diplod progenitor of the D subgenome of the G.barbadense8. G.mustelinum has 26 red A subgenome taking G.mustelinum chromosome as target DNA, G.herbaceum.var.africanum as probe and salmon DNA as block DNA. and there are 2 major NORs located in the A subgenome without another 4 NOR. and there are 2 NORs if G.mustelinum is target DNA, G.herbaceum as probe and G.davisonii as block DNA. All of the NORs of G.mustelinum are located in the A subgenome based on the Double stained Fluorescence in situ hybridization. and all of the 45S rDNA have been homogenized to a A genome repeat type.9. G.thurberi is the the diplod progenitor of D subgenome of the G.mustelinum更多还原