Colección Nacional de Insectos, Instituto de Biología, Universidad Nacional Autónoma de México, 3er. circuito exterior s/n, Cd. Universitaria, Copilco Coyoacán, A. P. 70-233, C. P. 04510. D. F., Mexico.
Mol Phylogenet Evol. 2012 Jan;62(1):485-95. doi: 10.1016/j.ympev.2011.10.018. Epub 2011 Nov 7.
Various DNA sequence-based methods for species delineation have recently been developed to assess the species-richness of highly diverse, neglected invertebrate taxa. These methods, however, need to be tested under a variety of conditions, including the use of different markers and parameters. Here, we explored the species diversity of a species-rich group of braconid parasitoid wasps, the Neotropical genus Notiospathius, including 233 specimens from 10 different countries. We examined sequences of two mitochondrial (mt) (COI, cyt b) and one nuclear (wg) gene fragments. We analysed them separately as well as concatenating the mt data with the general mixed Yule-coalescent (GMYC) model for species delineation using different tree-building methods and parameters for reconstructing ultrametric trees. We evaluated the performance of GMYC analyses by comparing their species delineations with our morphospecies identifications. Reconstructing ultrametric trees with a relaxed lognormal clock rate using the program BEAST gave the most congruent results with morphology for the two mt markers. A tree obtained with wg using the programs MrBayes+Pathd8 had the fewest cases of incongruence with morphology, though the performance of this nuclear marker was considerably lower than that of COI and cyt b. Species delimitation using the coalescent prior to obtain ultrametric trees was morphologically more congruent with COI, whereas the Yule prior was more congruent with cyt b. The analyses concatenating the mt datasets failed to recover some species supported both by morphology and the separate analyses of the mt markers. The highest morphological congruence was obtained with the GMYC analysis on an ultrametric tree reconstructed with cyt b using the relaxed lognormal clock rate and the Yule prior, thus supporting the importance of using alternative markers when the information of the barcoding locus (COI) is not concordant with morphological evidence. Seventy-one species were delimited based on the congruence found among COI, cyt b and morphology. Both mt markers also revealed the existence of seven potential cryptic species. This high species richness from a scattered geographical sampling indicates that there is a remarkable number of Notiospathius species that remains undiscovered.
最近开发了各种基于 DNA 序列的方法来划分物种，以评估高度多样化、被忽视的无脊椎动物类群的物种丰富度。然而，这些方法需要在各种条件下进行测试，包括使用不同的标记和参数。在这里，我们探索了一个物种丰富的 Braconid 寄生蜂属，即新热带 Notiospathius 属的物种多样性，包括来自 10 个不同国家的 233 个标本。我们检查了两个线粒体 (mt)（COI、cyt b）和一个核 (wg) 基因片段的序列。我们分别分析了这些序列，以及将 mt 数据与通用混合 Yule 合并 (GMYC) 模型结合使用不同的建树方法和参数来进行物种划分，以重建超支树。我们通过将 GMYC 分析的物种划分与我们的形态种识别进行比较来评估 GMYC 分析的性能。使用程序 BEAST 以松弛的对数正态钟速率重建超支树，对于这两个 mt 标记与形态学结果最为一致。使用程序 MrBayes+Pathd8 用 wg 构建的树与形态学的不一致性最少，尽管该核标记的性能明显低于 COI 和 cyt b。使用合并先验获得超支树的分支分析与 COI 在形态学上更为一致，而 Yule 先验与 cyt b 更为一致。联合 mt 数据集的分析未能恢复一些得到形态学和 mt 标记单独分析支持的物种。使用松弛的对数正态钟速率和 Yule 先验在 cyt b 重建的超支树上进行 GMYC 分析获得了最高的形态学一致性，因此当条形码基因座（COI）的信息与形态学证据不一致时，使用替代标记非常重要。根据 COI、cyt b 和形态学之间的一致性确定了 71 个种。这两个 mt 标记也揭示了七个潜在的隐种存在。从分散的地理采样中获得的这种高物种丰富度表明，仍有大量的 Notiospathius 种未被发现。
