Wang X-B, Deng J, Zhang J-T, Zhou Q-S, Zhang Y-Z, Wu S-A
The Key Laboratory for Silviculture and Conservation of Ministry of Education,Beijing Forestry University,Beijing 100083,China.
Key Laboratory of Zoological Systematics and Evolution,Institute of Zoology,Chinese Academy of Sciences,Beijing 100101,China.
Bull Entomol Res. 2015 Oct;105(5):545-54. doi: 10.1017/S0007485315000413. Epub 2015 May 20.
The soft scales (Hemiptera: Coccoidea: Coccidae) are a group of sap-sucking plant parasites, many of which are notorious agricultural pests. The quarantine and economic importance of soft scales necessitates rapid and reliable identification of these taxa. Nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene (barcoding region) and 28S rDNA were generated from 340 individuals of 36 common soft scales in China. Distance-based [(best match, Automated Barcode Gap Discovery (ABGD)], tree-based (neighbor-joining, Bayesian inference), Klee diagrams, and general mixed Yule coalescent (GMYC) models were used to evaluate barcoding success rates in the data set. Best match showed that COI and 28S sequences could provide 100 and 95.52% correct identification, respectively. The average interspecific divergences were 19.81% for COI data and 20.38% for 28S data, and mean intraspecific divergences were 0.56 and 0.07%, respectively. For COI data, multiple methods (ABGD, Klee, and tree-based methods) resulted in general congruence with morphological identifications. However, GMYC analysis tended to provide more molecular operational taxonomic units (MOTUs). Twelve MOTUs derived from five morphospecies (Rhodococcus sariuoni, Pulvinaria vitis, Pulvinaria aurantii, Parasaissetia nigra, and Ceroplastes rubens) were observed using the GMYC approach. In addition, tree-based methods showed that 28S sequences could be used for species-level identification (except for Ceroplastes ceriferus - Ceroplastes pseudoceriferus), even with low genetic variation (<1%). This report demonstrates the robustness of DNA barcoding for species discrimination of soft scales with two molecular markers (COI and 28S) and provides a reliable barcode library and rapid diagnostic tool for common soft scales in China.
绵蚧（半翅目：蚧总科：蚧科）是一类吸食植物汁液的寄生虫，其中许多是臭名昭著的农业害虫。绵蚧的检疫和经济重要性使得快速、可靠地鉴定这些分类单元成为必要。从中国36种常见绵蚧的340个个体中获取了线粒体细胞色素c氧化酶亚基I（COI）基因（条形码区域）和28S rDNA的核苷酸序列。基于距离的方法（最佳匹配、自动条形码间隙发现法（ABGD））、基于树的方法（邻接法、贝叶斯推断）、克莱图以及广义混合尤尔合并（GMYC）模型被用于评估数据集中条形码的成功率。最佳匹配结果表明，COI和28S序列分别能提供100%和95.52%的正确鉴定率。COI数据的种间平均差异为19.81%，28S数据的种间平均差异为20.38%，种内平均差异分别为0.56%和0.07%。对于COI数据，多种方法（ABGD、克莱图和基于树的方法）与形态学鉴定结果总体一致。然而，GMYC分析倾向于提供更多的分子操作分类单元（MOTU）。使用GMYC方法观察到，从五个形态物种（红圆蚧、葡萄绵蚧、橘绵蚧、黑褐圆盾蚧和红蜡蚧）中得出了12个MOTU。此外，基于树的方法表明，即使遗传变异较低（<1%），28S序列也可用于物种水平的鉴定（蜡蚧属除外）。本报告证明了利用两种分子标记（COI和28S）进行DNA条形码技术对绵蚧进行物种鉴别具有稳健性，并为中国常见绵蚧提供了可靠的条形码文库和快速诊断工具。
