【摘要】 为探讨rDNA在重楼属ParisL .中的分布规律 ,利用荧光原位杂交 （FISH）对 4种重楼属植物的 1 8₂ 6SrDNA进行了定位。所有植物均为二倍体 ,基因组由A、B、C、D和E 5条染色体构成。 （ 1 ）滇重楼P .polyphyllavar.yunnanensis:2n =1 0 =6m + 4t,C和D染色体的短臂上各有 1个 1 8₂ 6SrDNA位点 ;（ 2 ）长柱重楼P .forrestii:2n=1 0 =6m + 4t,B染色体的长臂、C和D染色体的短臂上各有 1个位点 ;（ 3）五指莲P .axialis:2n =1 0 =6m（ 2sat） + 4t（ 2sat） + 1 - 2B ,C和D染色体的短臂上各有 1个位点 ;在有 1个B染色体的细胞中 ,B染色体没有信号点 ,而有 2个B染色体的细胞中 ,只有 1个B染色体上有信号点 ,表明B染色体上有基因存在且其分裂不均等 ;（ 4 ）大理重楼P .daliensis:2n =1 0 =4m + 2sm + 2st+ 2t,C染色体的短臂上有 1个位点。1 8₂ 6SrDNA位点不仅出现在染色体的次缢痕上 ,也出现在非次缢痕位点。另外 ,4个种中C染色体短臂末端均有 1 8₂ 6SrDNA。更多还原

【Abstract】 S rDNA loci were mapped on chromosomes in four species of Paris , and the number and position of rDNA sites in these species were compared for analysis of the distribution of the sites. All the plants were diploids, and the genome consisted of five chromosomes, A, B, C, D and E. （1） P. polyphylla var. yunnanensis, 2n=10=6m+4t. Two 18₂6S rDNA loci were detected on the short arms of C and D chromosomes; （2） P. forrestii , 2n=10=6m+4t. One locus was detected on the long arm of B chromosome, and also two loci on the short arms of C and D chromosomes; （3） P. axialis . 2n=10=6m（2sat）+4t（2sat）+1-2B. Two loci were detected on the short arms of C and D chromosomes. One locus was detected in the cell with two B_chromosomes （B）, but none was detected in that with only one B chromosome, indicating that rRNA gene existed on B chromsome, and an unequal division occurred during mitotic cycle of B_chromosomes. （4） P. daliensis , 2n=10=4m+2sm+2st+2t. One locus was detected on the short arm of D chromosome. The signals of 18₂6S rDNA appeared not only in the second constriction but also in the other regions of chromosome. It is noteworthy that one locus was detected in the terminal region on the short arm of C chromosome in all the four species studied.更多还原