Institut Botànic de Barcelona (CSIC-ICUB), Passeig del Migdia s/n, 08038 Barcelona, Catalonia, Spain.
Genome. 2009 Dec;52(12):1012-24. doi: 10.1139/G09-077.
Subgenus Tridentatae (Artemisia, Asteraceae) can be considered a polyploid complex. Both polyploidy and hybridization have been documented in the Tridentatae. Fluorescent in situ hybridization (FISH) and fluorochrome banding were used to detect and analyze ribosomal DNA changes linked to polyploidization in this group by studying four diploid-polyploid species pairs. In addition, genome sizes and heterochromatin patterns were compared between these populations. The linked 5S and 35S rRNA genes are confirmed as characteristic for Artemisia, and a pattern at the diploid level of three rDNA loci located at telomeric positions proved to be typical. Loss of rDNA loci was observed in some polyploids, whereas others showed additivity with respect to their diploid relatives. Genome downsizing was observed in all polyploids. Banding patterns differed depending on the pair of species analysed, but some polyploid populations showed an increased number of heterochromatic bands. FISH and fluorochrome banding were useful in determining the systematic position of Artemisia bigelovii, for which a differential pattern was found as compared with the rest of the group. Additionally, FISH was used to detect the presence of the Arabidopsis-type telomere repeat for the first time in Artemisia.
刺苞菊亚属（蒿属，菊科）可被视为一个多倍体复合体。多倍体和杂交在刺苞菊亚属中都有记载。通过研究四个二倍体-多倍体种对，使用荧光原位杂交（FISH）和荧光带型技术来检测和分析与该组多倍化相关的核糖体 DNA 变化。此外，还比较了这些群体之间的基因组大小和异染色质模式。连锁的 5S 和 35S rRNA 基因被确认为蒿属的特征，并且位于端粒位置的三个 rDNA 基因座的二倍体水平上的模式被证明是典型的。在一些多倍体中观察到 rDNA 基因座的丢失，而其他多倍体则相对于其二倍体亲属表现出加性。所有多倍体都观察到基因组缩小。带型模式因分析的种对而异，但一些多倍体群体显示出异染色质带的数量增加。FISH 和荧光带型技术在确定 Artemisia bigelovii 的系统位置方面非常有用，与该组的其余部分相比，发现了不同的模式。此外，首次使用 FISH 在蒿属中检测到拟南芥型端粒重复。
