【作者】 赵侯明；

【导师】 宋发军； 覃瑞；

【作者基本信息】 中南民族大学 ， 生物化学与分子生物学， 2008， 硕士

【摘要】 1.利用Gimesa显带技术对冬凌草进行了染色体数目和染色体核型分析,研究结果表明,冬凌草染色体数目为2n=2x=24,相对长度组成为2n=2x=24=10M2+14M1,核型公式为K(2n)=2x=24=16m+8sm。此外,本研究中,G-显带条纹数目虽然有限,但能准确的反映染色体结构特点,从染色体水平初步推测冬凌草在系统演化上可能属于较原始的种类。2.用高杆野生稻(CCDD) C0t-1 DNA作为探针,对其自身体细胞染色体和宽叶野生稻(CCDD)体细胞染色体进行荧光原位杂交实验。同源染色体呈现相似的杂交带型,对其核型进行同源性聚类。杂交结果表明,这2种野生稻所有染色体上均有信号分布,主要分布在染色体的着丝粒,近着丝粒和端粒,同时染色体的信号都是24条染色体信号较强,24条染色体信号较弱。2种野生稻较强信号的24条染色体信号非常一致,而高杆野生稻的较弱信号的24条染色体明显的比宽叶野生稻较弱的信号24条染色体强,说明四倍体高杆野生稻和宽叶野生稻CD基因组中一个基因组比较保守,另一个基因组差异相对较大,结合C基因组的C0t-1 DNA对两个种的荧光原位杂交研究表明保守的基因组应该是C基因组,差异的为D基因组。上述结果表明,C0t-1 DNA具有很强的种的特异性和依赖基因组型的特异性,利用C0t-1 DNA进行荧光原位杂交能够更有效的研究物种基因组之间的关系。同时,通过高杆野生稻C0t-1 DNA荧光原位杂交对两个同基因组的异源四倍体中高度重复序列进行了比较分析,对重复序列在稻属多倍体进化过程中的机制进行了初步的探讨。3.利用药用野生稻CC基因组作为探针,对高杆野生稻和宽叶野生稻(CCDD)体细胞分裂中期染色体进行荧光原位杂交实验。在一定的杂交严谨度条件下,同源性高的表现出强的杂交信号,而同源性比较低的则信号弱,因此,杂交信号强的那部分染色体就是C基因组的染色体,从而把CCDD基因组中的C,D基因组染色体分开。杂交结果表明,在杂交严谨度合适的条件下,这两种四倍体的野生稻的48条染色体有一部分有信号,而另一部分则信号相对较弱或几乎没有信号。其中,高杆野生稻的48条染色体中,无论怎么调整杂交严谨度都不能很好的把C基因组染色体分开成24条,而宽叶野生稻能够很好的区分强信号的染色体和弱信号的染色体分别是24条。说明高杆野生稻和宽叶野生稻基因组还是存在着一定的差异。同时,通过比较高杆野生稻和宽叶野生稻染色体上信号的分布特点,我们对稻属异源多倍体的起源和进化机制进行了初步的探讨。更多还原

【Abstract】 1.The number and karyotype of the Rabdosia rubescens (Hemsl.) Hara was studied by using G-band method in this work. The results shows that the chromosome number of the specie is 2n=2x=24, constitution of relative length was 2n=10M2+14M2,karyotype formula was K(2n)=2x=24=16m+8sm. The accuracy of karyotyp analysis of the choromosome was improved by bands of the G-band because it can revealed the struction of the chromosomes . Base on the result of chromosomal characteristics, speculated that the R. rubescens was speculated that belong to the more original species.2.Fluorescence in situ hybridization (FISH) procedure was employed to investigate relationships and comparative analysis between Oryza.alta and O.latifolia with the probe of C0t-1 DNA from O.alta.The homologous category on karyotype analysis of the Oryza.alta and O.latifolia, base on the banding of C0t-1 DNA which the homologous chromosomes shows the similar signal bandings of C0t-1 DNA.The result showed that all the chromosomes displayed signals which mainly located in the centromere of chromosomes, the proximal centromere and the telomere, while the 24 chromosomes present shrong sigals than the other 24 in both two species.More interesting, the strong signals of the two amphidiploid species which has the same CCDD genome appeared similar while their weak sigals is different, according to the previously shudy,it is concluded that the similar part is belong to the C genome and the different part is may belong to the D geonome. The results above reveal that C0t-1 DNA has its high specificity to a certain genome/species during evolution, and it can be used as a probe in FISH for studing the relationships of species more effiently. Moreover, according to comparative analysis of the highly repetitive sequence and the moderate repeats of O.alta and O.latifolia using FISH based on the C0t-1 DNA probe from O.alta, the origin mechanism of allotetraploid in genus Oryza was also discussed. 3.Fluorescence in situ hybridization (FISH) procedure was employed to investigate relationships and comparative analysis between Oryza.alta and O.latifolia with the probe of gDNA from Oryza officinalis Wall.in the.in a right hybridization strict the probe can identified the C and D genome.because of the hight homologous.shows the strong signal.The results shows the signal on the chromosomes C and D genome is different.the shrong signal chromosomes belong to the C genome while the others weak signal The result shows that the CCDD of the O.alta cannot identified the C Genome clear as 24 chromosomes while the O.latifolia can.It is shows that there are very different between the two CCDD genomic species. The origin of allotetraploid in genus Oryza was also discussed.更多还原