Identification of chromosomes of Chrysanthemum sensu lato in Japan with FISH and GISH

1997年，应用荧光原位杂交技术（FISH）对日本菊花（Chrysanthemum sensu lato）染色体进行了研究。分布在中国的四倍体种d.i indicum、d.g yoshinaganthum和d.c anetii在有丝分裂中期普遍在卫星染色体的卫星上出现rDNA位点。显示rDNA位点的染色体数在籼稻和毛茛中分别为8个和10个，且在两种植物中都非常稳定。因此，它们一定是一种很有前途的方法来分析它们的系统发育关系和物种间的杂交。此外，在所有物种中，有丝分裂前期和间期某些染色体的rDNA位点数目与有丝分裂中期的rDNA位点数目一致。1997年在广岛和山口县采集的二倍体植物D.boreale和d.a japonicum保存在广岛大学理学院植物染色体和基因库实验室。这两个物种在卫星上的rDNA位点与所研究的四倍体物种相似。显示rDNA位点的染色体数分别为6条和4条。这些结果有助于验证所研究的两个物种之间的渐渗杂交现象。用FISH方法研究了黄菊花、日本黄菊花及其人工杂种的染色体。两个种和一个杂交种通常在卫星染色体的卫星上显示rDNA位点；c系显示4个主要杂交信号和2个次要杂交信号；日本血吸虫表现出两种杂交信号；人工杂交表现出四种杂交信号。另一方面，利用全基因组原位杂交技术（GISH）对人工杂交的染色体进行研究。人工杂交在较大的染色体组上显示出杂交信号，其中染色体长臂和短臂末端的杂交信号比染色体上其他区域的杂交信号更亮。此外，GISH还观察到人工杂种F_1的减数分裂染色体，并观察到一些二价染色体和易位。少

In 1997 fluorescence in situ hybridization (FISH) with a rDNA probe, pTa 71 isolated from wheat, was applied to investigate chromosomes of Chrysanthemum sensu lato in Japan.Tetraploid species, D.indicum, D.yoshinaganthum and D.chanetii which was distributed in China commonly showed rDNA site at the satellite of the sat-chromosome at mitotic metaphase. The numbers of chromosomes displaying rDNA site were eight in D.indicum and D.chanetti, and ten in D.yoshinaganthum, and were very stable within each species. Thus, they must be the promising method to analyze their phylogenetical relationship and hybridization among species. Moreover, the nembers of rDNA sites of certain chromosomes at interphase and mitotic prophase corresponded with that at mitotic metaphase in all species.Diploid species, D.boreale and D.japonicum were collected from Hiroshima and Yamaguchi Prefectures in 1997, and were conserved in the Laboratory of plant Chromosome and Gene Stock, Faculty of Science, Hiroshima Unive … More rsity. These two species showed rDNA site at the satellite like the tetraploid species studied. The numbers of chromosomes displaying rDNA site were six in D.boreale and four in D.japonicum. These results contributed to verify the phenomenon of introgressive hybridization between the two species studied.Chromosomes of Chrythanthemum lineare, C.nipponicum and their artificial hybrid were also investigated by FISH.Two species and one hybrid commonly showed rDNA site at the satellite of the sat-chromosome ; C.lineare showed four major and two miner hybridization sugnals ; C.nipponicum showed two hybridization signals ; and artificial hybrid showed four hybridization signals. On the other hand, total genomic in situ hybridization (GISH) with total genomic DNA of C.lineare was performed to investigate chromosomes of artificial hybrid. Artificial hybrid showed hybridization signal on larger chromosome set which must be orgin ated from C.lineare, especially, hybridization signals at the terminal regions of the long and short arms of each chromosomes were brighter than the other region on chromosomes. Moreover, meiotic chromosomes of artificial hybrid F_1 was observed with GISH,and some bivalent chromosomes and translocations were observed. Less