Department of Genetics, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.
Department of Crop Protection, Ahmadu Bello University, Samaru, 810001, Zaria, Nigeria.
Sci Rep. 2020 Jun 1;10(1):8893. doi: 10.1038/s41598-020-65880-7.
Trioza erytreae is the main vector for 'Candidatus Liberibacter africanus', the causative agent of African Citrus Greening disease. The insect is widespread in Africa, and has recently disseminated to Southwestern Europe. This study aimed at generating reference mitogenome sequences for T. erytreae, as a background for future genetic diversity surveys. Complete mitochondrial sequences of three specimens collected in Ethiopia, Uganda and South Africa were recovered using Ion Torrent technology. The mitogenomes of T. erytreae from Uganda and Ethiopia were highly similar, and distinct from that found in South Africa. The phylogeographic structure of T. erytreae was assessed using genetic clustering and pairwise distances, based on a dataset of public COI sequences recorded as T. erytreae. The dataset revealed ten haplotypes with strong phylogeographic structure in Africa and Europe. Three haplotypes found in Kenya on Clausena anisata belonged to pairs separated by distances as high as 11.2%, and were basal to all other sequences. These results indicate that not all sequences identified as T. erytreae belong to the same species, and that some degree of specificity with different plant hosts is likely to exist. This study provides new baseline information on the diversity of T. erytreae, with potential implications for the epidemiology of African Citrus Greening disease.
三叶斑潜蝇是“非洲韧皮部杆菌”的主要载体，“非洲韧皮部杆菌”是非洲柑橘绿斑病的病原体。这种昆虫在非洲广泛分布，最近已传播到西南欧。本研究旨在为三叶斑潜蝇生成参考线粒体基因组序列，作为未来遗传多样性调查的背景。使用 Ion Torrent 技术从埃塞俄比亚、乌干达和南非采集的三个标本中回收了完整的线粒体序列。乌干达和埃塞俄比亚的三叶斑潜蝇线粒体基因组非常相似，与南非的有所不同。基于记录为三叶斑潜蝇的 COI 序列的公共数据集，使用遗传聚类和成对距离评估了三叶斑潜蝇的系统地理结构。该数据集在非洲和欧洲揭示了具有强烈系统地理结构的 10 个单倍型。在肯尼亚对 Clausena anisata 上发现的 3 个单倍型属于距离高达 11.2%的成对，并且是所有其他序列的基础。这些结果表明，并非所有鉴定为三叶斑潜蝇的序列都属于同一物种，并且不同植物宿主之间可能存在一定程度的特异性。本研究为三叶斑潜蝇的多样性提供了新的基线信息，对非洲柑橘绿斑病的流行病学可能具有重要意义。
