Department of Plant Taxonomy & Nature Conservation, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland.
Department of Plant Cytology and Embryology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland.
Int J Mol Sci. 2022 Apr 1;23(7):3948. doi: 10.3390/ijms23073948.
Despite the clear circumscription of tribe Sobralieae (Orchidaceae), its internal relationships are still dubious. The recently delimited genus , based on previous species, is now assumed to be paraphyletic, with a third genus, , nested in it. The morphology of these three genera is significantly different, indicating the necessity of new data for a better genera delimitation. Though morphology and molecular data are available, cytogenetics data for Sobralieae is restricted to two and one species. Aiming to evaluate the potential of cytogenetic data for genera delimitation, we present chromosome number and genome size data for 21 and 20 species, respectively, and used such data to infer the pattern of karyotype evolution in these genera. The analysis allowed us to infer x = 24 as the base chromosome number and genome size of average 1C-value of 5.0 pg for the common ancestor of . The recurrent descending dysploidy in Sobralieae and the punctual genome upsize suggest a recent diversification in Sobralieae but did not allow differing between and . However, the basal position of tribe Sobralieae in the subfamily Epidendroideae makes this tribe of interest to further studies clarifying the internal delimitation and pattern of karyotype evolution.
尽管 Sobralieae 族（兰科）的边界划分明确，但它的内部关系仍然存在疑问。最近根据先前的物种定义的属现在被认为是并系的，而第三个属则嵌套在其中。这三个属的形态明显不同，表明需要新的数据来更好地界定属。尽管有形态学和分子数据，但 Sobralieae 的细胞遗传学数据仅限于两个和一个物种。为了评估细胞遗传学数据在属的界定中的潜力，我们分别为 21 种和 20 种提供了染色体数和基因组大小的数据，并利用这些数据推断了这些属的核型进化模式。分析表明，x = 24 是 的基础染色体数，而 的共同祖先的基因组大小平均为 1C 值为 5.0pg。Sobralieae 中的反复下降的非整倍性和点状的基因组增大表明 Sobralieae 最近发生了多样化，但无法区分 和 。然而，Sobralieae 族在 Epidendroideae 亚科中的基础位置使其成为进一步研究澄清核型进化内部界限和模式的有趣对象。
