Abstract：
The utility of a universal DNA \'barcode\' fragment (658 base pairs of the Cytochrome C Oxidase I [COI] gene) has been established as a useful tool for species identification, and widely criticized as one for understanding the evolutionary history of a group. Large amounts of COI sequence data have been produced that hold promise for rapid species identification, for example, for biosecurity. The fruit fly tribe Dacini holds about a thousand species, of which 80 are pests of economic concern. We generated a COI reference library for 265 species of Dacini containing 5601 sequences that span most of the COI gene using circular consensus sequencing. We compared distance metrics versus monophyly assessments for species identification and although we found a \'soft\' barcode gap around 2% pairwise distance, the exceptions to this rule dictate that a monophyly assessment is the only reliable method for species identification. We found that all fragments regularly used for Dacini fruit fly identification >450 base pairs long provide similar resolution. 11.3% of the species in our dataset were non-monophyletic in a COI tree, which is mostly due to species complexes. We conclude with recommendations for the future generation and use of COI libraries. We revise the generic assignment of Dacus transversus stat. rev. Hardy 1982, and Dacus perpusillus stat. rev. Drew 1971 and we establish Dacus maculipterus White 1998 syn. nov. as a junior synonym of Dacus satanas Liang et al. 1993.
摘要：
通用DNA“条形码”片段（细胞色素C氧化酶I[COI]基因的658个碱基对）已被确立为物种鉴定的有用工具，并被广泛批评为理解一个群体的进化史。已经产生了大量的COI序列数据，这些数据有望快速鉴定物种，例如,生物安全。果蝇部落Dacini拥有大约一千种，其中80是经济关注的害虫。我们使用环状共有测序产生了265种Dacini的COI参考文库,其包含跨越大部分COI基因的5601序列。我们比较了距离指标与单亲评估的物种识别，尽管我们发现了一个“软”条形码间隙，大约2%的成对距离，该规则的例外情况表明，单方评估是物种鉴定的唯一可靠方法。我们发现，所有定期用于Dacini果蝇鉴定的片段>450个碱基对提供相似的分辨率。在我们的数据集中，11.3%的物种在COI树中是非单系的，这主要是由于物种复合物。最后，我们为COI库的未来生成和使用提供了建议。我们修改了Dacustransversusstat的通用赋值。rev.哈代1982年，达克斯·佩尔普西勒斯。rev.Drew1971和我们建立了DacusmaculipterusWhite1998syn。11月。作为DacussatanasLiang等人的初级同义词。1993.
