Calypsoinae is a small subtribe in Orchidaceae (Epidendroideae) characterized by diverse trophic strategies and morphological characters. Calypsoinae includes 13 genera, four of which are leafless and mycoheterotrophic. Mycoheterotrophic species in the leafless genus Corallorhiza are well-suited to studies of plastome evolution. However, the lack of plastome sequences for other genera in Calypsoinae limits the scope of comparative and phylogenetic analyses, in particular our understanding of plastome evolution. To understand plastid genome evolution in Calypsoinae, we newly sequenced the plastomes of 12 species in the subtribe, including representatives of three mycoheterotrophic genera as well as five autotrophic genera. We detected two parallel photosynthetic losses in Corallorhiza. Evolutionary analyses indicated that the transition to obligate mycoheterotrophy leads to the relaxation of selection in a highly gene-specific pattern.

中文翻译：

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Calypsoinae（Epidendroideae，兰科）质体基因组进化。

Calypsoinae是兰科（Epidendroideae）的一个小分支，其特征在于多种营养策略和形态特征。ly科包括13个属，其中四个是无叶和真菌异养的。无叶科（Corallorhiza）属的异养营养物种非常适合于质体组进化的研究。但是，在小鳞蝇科中缺乏其他属的质体序列限制了比较分析和系统发育分析的范围，特别是我们对质体进化的理解。为了了解Calypsoinae中质体基因组的进化，我们对亚部落中的12个物种的质体组进行了新的测序，包括3个异养异养属和5个自养属的代表。我们在Corallorhiza中检测到两个平行的光合作用损失。