中文摘要：

以小麦的45S rDNA为探针,采用荧光原位杂交技术对巴西橡胶树（Hevea brasiliensis）热研7-33-97的有丝分裂细胞进行了检测,结果发现,不同时期细胞内均能观察到4个信号位点,且这4个信号的大小和强弱存在差异。核型分析结果表明,这4个信号位点被分别定位在6号和7号染色体上,其中,信号较小较弱的1个位点位于6号染色体的1条同源染色体次缢痕处,信号较大较强的位点位于6号染色体的另1条同源染色体的次缢痕及随体处,其余的信号位点位于7号1对同源染色体的次缢痕及随体处,信号大小和强度介于前两者之间。

英文摘要：

The position and number of 45 S rDNA on mitotic chromosomes of the young leaf collected from the rubber tree of Clone Reyan7-33-97（ Hevea brasiliensis Müll. Arg.） at the bronze leaf stage were detected by using fluorescence in situ hybridization（ FISH） analysis with 45 S rDNA from wheat as a probe. Four hybridization signals with different sizes and strength were found in different mitotic phases. According to the karyotype analysis,the loci of 4 signals were found on chromosomes pairs 6 and 7. A small faint signal was detected at the secondary constriction of one member of chromosome pair 6,and a large strong signal was detected at the secondary constriction and satellite of another member of chromosome pair 6. The other two signals with their sizes and strength between those of the members of chromosome pair 6 were all detected at the secondary constriction and satellite of chromosome pair 7.