Department of Evolution and Ecology, University of California, Davis, Davis, CA 95616, USA.
Lankester Botanical Garden, University of Costa Rica, P.O. Box 302-7050, Cartago 30109, Costa Rica.
G3 (Bethesda). 2024 Nov 6;14(11). doi: 10.1093/g3journal/jkae211.
Orchidaceae is one of the most prominent flowering plant families, with many species exhibiting highly specialized reproductive and ecological adaptations. An estimated 10% of orchid species in the American tropics are pollinated by scent-collecting male euglossine bees; however, to date, there are no published genomes of species within this pollination syndrome. In this study, we present the first draft genome of an epiphytic orchid from the genus Gongora, a representative of the male euglossine bee-pollinated subtribe Stanhopeinae. The 1.83-Gb de novo genome with a scaffold N50 of 1.7 Mb was assembled using short- and long-read sequencing and chromosome capture (Hi-C) information. Over 17,000 genes were annotated, and 82.95% of the genome was identified as repetitive content. Furthermore, we identified and manually annotated 26 terpene synthase genes linked to floral scent biosynthesis and performed a phylogenetic analysis with other published orchid terpene synthase genes. The Gongora gibba genome assembly will serve as the foundation for future research to understand the genetic basis of floral scent biosynthesis and diversification in orchids.
兰科是开花植物中最显著的科之一，许多物种表现出高度特化的生殖和生态适应。估计在美洲热带地区，有 10%的兰花物种是由气味收集的雄性腰果树蜂授粉的；然而，迄今为止，在这种授粉综合征中还没有发表过物种的基因组。在这项研究中，我们提出了第一个来自 Gongora 属的附生兰花的基因组草案，该属是雄性腰果树蜂授粉的 subtribe Stanhopeinae 的代表。使用短读和长读测序以及染色体捕获（Hi-C）信息，组装了 1.83-Gb 的从头基因组，支架 N50 为 1.7 Mb。超过 17,000 个基因被注释，82.95%的基因组被鉴定为重复内容。此外，我们鉴定并手动注释了 26 个与花香生物合成相关的萜烯合酶基因，并与其他已发表的兰花萜烯合酶基因进行了系统发育分析。Gongora gibba 基因组组装将为未来研究提供基础，以了解兰花花香生物合成和多样化的遗传基础。
