摘要
利用45S rDNA作为探针,通过荧光原位杂交（FISH）技术对同样含有CCDD基因组的高秆野生稻（Oryza alta）和宽叶野生稻（O.latifolia）进行rDNA的荧光原位杂交定位分析和核型分析。结果显示：宽叶野生稻中45S rDNA信号分布于多条染色体上,位点数目为10-16;高秆野生稻中有6个信号点,分布于3对同源染色体上,其中2对信号位点位于染色体短臂,1对位于染色体长臂。研究结果表明,高秆野生稻45S rDNA在基因组中位点数目稳定,宽叶野生稻中45S rDNA位点数在不同个体中呈现一定的动态变化,显示这2种野生稻基因组存在一定差异;核型分析结果也表明二者基因组存在较大的差异。由此推测,高秆野生稻分化较早而趋向稳定,宽叶野生稻可能形成较晚,还处于进化过程之中。鉴于二者在基因组结构上的明显差异和进化上的不平衡性,建议把这2种野生稻划分为不同野生稻种,可能会更加符合二者的进化特性。同时,讨论了45S rDNA在染色体中分布特点与机制。
45S rDNA probes were used to analyze Oryza alta and （9. latifolia both having CCDD ge- homes with fluorescence in situ hybridization. The results showed that the hybridization signals of 45S rDNA in O. latifolia chromosome preparations were distributed on different chromosomes with the number of 10-16. The same signal in O. alta chromosome preparations was 6 and distributed on the cer- tain three pairs homologous chromosomes,with two pairs in short chromosome arms and the other one pair in long chromosome arm. The number and position of 45S rDNA signals were stabled in O. alta ge- nome,but there were some dynamic changes of signals in O. latifolia genome. It is indicated that there were differences between these two kinds of CCDD O. alta chromosomes and O. latifolia chromosomes genomes. Comparatively analyzing the karyotype of based on the fluorescence in situ hybridization pic- tures showed that there were greater differences. It is proposed that O. alta maybe differentiate earlier and tend to be stable, while O. latifolia may be still in its evolutionary process. Based on the imbalance of evolution and differences of genomic structure, O. alta and O. latifolia were divided into two wild rice species, which may be well conformed with their evolutionary characteristics. The mechanism and char- acteristics of 45S rDNA＇s distribution in the chromosomes were discussed.
出处
《华中农业大学学报》
CAS
CSCD
北大核心
2015年第3期1-7,共7页
Journal of Huazhong Agricultural University
基金
湖北省自然科学基金重点项目(BZZ11004)
