Chromosomal evolution in Pleurothallidinae (Orchidaceae: Epidendroideae) with an emphasis on the genus Acianthera: chromosome numbers and heterochromatin
Chromosomal evolution in Pleurothallidinae (Orchidaceae: Epidendroideae) with an emphasis on the genus Acianthera: chromosome numbers and heterochromatin
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DOI：
10.1111/boj.12273
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发表时间：
2015-05-01
影响因子：
2.4
通讯作者：
Felix, Leonardo P.
中科院分区：
文献类型：
--
作者：
De Oliveira, Irenice Gomes;Moraes, Ana Paula;Felix, Leonardo P.
本研究以侧叶兰亚族（Pleurothallidinae）12属48种兰科植物的染色体数目变异和色霉素A（3）/4，6-diamidino-2-phenylindole（CMA/DAPI）带型为研究对象，旨在从系统发育假说和分类学角度探讨侧叶兰亚族的染色体进化。所有物种的染色体都很小，其中两种Specklinia spp的染色体数目在2n=20之间。在本研究中最具代表性的属--种间上升和主要是下降的异倍性是侧珠亚族染色体数目进化的主要机制。对侧囊藻亚科，x=20为基本染色体数，对相关亚族Laeliinae和整个族Epidendelae，x = 20为基本染色体数。巴西种的大属Stelis的染色体有少量的异染色质和染色体数目的基础上x（2）=16。这些通常是不同的安第斯山脉和中美洲物种的报道，但在协议提出的单系假说Stelis属。巴西大西洋分布。(c)2015年，伦敦林奈学会，林奈学会植物学杂志，2015年，178，102-120。
In this study, we analysed chromosome number variation and chromomycin A(3)/4,6-diamidino-2-phenylindole (CMA/DAPI) banding patterns in 48 species belonging to 12 genera of subtribe Pleurothallidinae (Orchidaceae) in order to understand the chromosome evolution based on recent phylogenetic hypotheses and taxonomic treatments. All species had small chromosomes, with numbers ranging from 2n=20 in two Specklinia spp. to 2n=80 in an unidentified Octomeria sp. In Acianthera, the most highly represented genus in this study, a great diversity of chromosome number and pattern of fluorescent bands was observed, showing heterochromatin accumulation in Acianthera section Sicariae subsection Pectinatae. Interspecific ascending and, mainly, descending dysploidy were the main mechanisms of chromosome number evolution in subtribe Pleurothallidinae. For Pleurothallidinae, x=20 is suggested as the basic chromosome number, the same suggested for the related subtribe Laeliinae and for the whole tribe Epidendreae. The Brazilian species of the mega-genus Stelis had chromosomes with small amounts of heterochromatin and chromosome numbers based on x(2)=16. These are generally divergent from those reported for Andean and Meso-American species, but in agreement with the monophyletic hypothesis proposed for Stelis spp. with a Brazilian Atlantic distribution. (c) 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 178, 102-120.