摘要
两个Ｅ基因组（包括Ｅｅ和Ｅｂ）特异ＲＡＰＤ片段和两个Ｓｔ基因组特异ＲＡＰＤ片段的序列分析表明，４个片段均为新的ＤＮＡ克隆片段。染色体原位杂交显示ＯＰＤ１２４４４为区域化连续高度重复序列，而ＯＰＦ０３１２９６（Ｅｂ特异）、ＯＰＢ０８５２５（Ｓｔ特异）、ＯＰＮ０１８１７（Ｓｔ特异）为弥散性高度重复序列。研究还显示：大部分ＤＮＡ高度重复序列在亲缘关系较近的小麦族植物基因组间是共享的，差异可能主要是在重复次数及片段长度上，而能否用ＲＡＰＤ技术扩增主要决定于某一基因组的这些重复序列中有无与特定引物相匹配的区域。文中就这些重复序列在小麦远缘杂交后代外源遗传物质检测、多倍体物种染色体组组成研究中的潜在价值进行了讨论。
? Two E genome(including Ee & Eb) and two Stgenomespecific RAPD markers were successfully cloned. Sequencing data indicated that the four DNA fragments were reported for the first time. Chromosome fluorescent in situ hybridization (FISH) showed that OPD12444 (Especific) was a highly tandem repeat. OPF031296 (Ebspecific), OPB08525 (Stspecific), and OPN01817 (Stspecific) were highly dispersed repetitive sequences. The FISH and Southern hybridization of genomic DNA also revealed that all of the four highly repetitive sequences were shared among relatively closer genomes of triticeae. The difference was mainly in the fragment length and the copy number. Whether a genome can amplify a specific sequence via RAPD is mainly dependent on if there are primering sites at both ends of this sequence in the genome. We also discussed the potentiality of these highly repetitive DNA fragments in detection of alien chromatin in wheat and determination of genome constitution of polyploid triticeae species.
关键词
基因组
RAPD标记
原位杂交
小麦族
Genome, RAPD marker, Clone, FISH, Southern hybridization
