Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China.
Mol Phylogenet Evol. 2020 May;146:106758. doi: 10.1016/j.ympev.2020.106758. Epub 2020 Feb 4.
The Bambusa-Dendrocalamus-Gigantochloa complex (BDG complex) is the most diversified and phylogenetically recalcitrant group of the paleotropical woody bamboos. Species of this complex occur in tropical and subtropical Asia and most of them are of great economic, cultural and ecological value. The lack of resolution achieved through the analyses of previous molecular datasets has long confounded its phylogenetic estimation and generic delimitation. Here, we adopted a ddRAD-seq strategy to investigate phylogenetic relationships of the four main genera (Bambusa, Dendrocalamus, Gigantochloa, and Melocalamus) in the BDG complex. A total of 102 species were sampled, and SNP data were generated. Both MP and ML analyses of the ddRAD-seq data resulted in a well-resolved topology with Gigantochloa and Melocalamus confirmed as monophyletic, and Melocalamus resolved as sister to the rest of the complex. Bambusa and Dendrocalamus were both resolved as paraphyletic. The phylogenetic relationships were mostly supported by morphological evidence including characters of the branch complement, rachilla, lodicules, filaments and stigma. We also generated and assembled complete plastid genomes of 48 representative species. There were conflicts between the plastome and the ddRAD topologies. Our study demonstrated that RAD-seq can be used to reconstruct evolutionary history of lineages such as the bamboos where ancient hybridization and polyploidy play a significant role. The four genera of the BDG complex have a complex evolutionary history which is likely a product of ancient introgression events.
丛生竹-牡竹-巨竹复合体（BDG 复合体）是热带木本竹类中最多样化和系统发育上最难处理的类群。该复合体的物种分布于热带和亚热带亚洲，其中大多数具有巨大的经济、文化和生态价值。先前的分子数据集分析未能解决的分辨率问题，长期以来一直困扰着其系统发育估计和属的划分。在这里，我们采用 ddRAD-seq 策略来研究 BDG 复合体中四个主要属（Bambusa、Dendrocalamus、Gigantochloa 和 Melocalamus）的系统发育关系。共采集了 102 个物种样本，并生成了 SNP 数据。ddRAD-seq 数据的 MP 和 ML 分析都产生了一个很好解决的拓扑结构，其中 Gigantochloa 和 Melocalamus 被确认为单系，而 Melocalamus 被解析为复合体其余部分的姐妹群。Bambusa 和 Dendrocalamus 都被解析为并系。系统发育关系主要得到形态学证据的支持，包括分枝补遗、叶舌、宿存花被片、花丝和柱头的特征。我们还生成并组装了 48 个代表种的完整质体基因组。质体基因组和 ddRAD 拓扑结构之间存在冲突。我们的研究表明，RAD-seq 可用于重建竹子等具有重要古老杂交和多倍体作用的谱系的进化历史。BDG 复合体的四个属具有复杂的进化历史，这很可能是古代渗入事件的产物。
