中文摘要：

利用染色体荧光原位杂交技术对45S rDNA在枳属6个品种体细胞中期染色体上的分布情况进行了分析。结果表明,供试品种皱皮枳、飞龙枳、日本枳、薄皮枳、泸溪枳和旺仓大叶枳上的45S rDNA杂交位点分别为5、5、5、6、6和4个,且间期核中的信号分布情况与染色体上基本一致。品种间在位点数目和信号分布区域方面存在差异,表现出一定的信号多态性。根据信号的分布情况,结果包括以下5类情况：第1类为信号分布在整个随体上和次缢痕区域;第2类为部分随体区域和次缢痕;第3类为次缢痕区域;第4类为着丝点附近;第五类为长臂或短臂端部区域。根据各品种的45S rDNA杂交信号的特异性,认为45S rDNA可用于枳属植物染色体及物种亲缘关系分析。

英文摘要：

Physical locations of 45S rDNA on mitotic metaphase chromosomes of six species in Poncirus were carried on by means of fluorescence in situ hybridization.The results showed that the 45S rDNA sites on mitotic metaphase chromosomes of Crinkle-skin,Flying dragon,Japanese,Thin-skin,Luxi and Wangcang large leaf in Poncirus were 5,5,5,6,6 and 4 which were the same as the sites on mitotic interphase.Among these species,the numbers and located regions of 45S rDNA sites were different.According to the located regions of signals on these species five types were detected.The first was that 45S rDNA loci were all region of satellite and secondary constriction;The others were partial region of satellite and secondary constriction,only secondary constriction,and pericentromeric regions and telomeric region in long or short arms.The results could be important to chromosome characteristics and genetic relationship analysis.