Plant Breeding, Wageningen University and Research Centre, Wageningen, The Netherlands.
Departamento de Biología Vegetal, Facultad de Agronomía, Universidad de la República, Montevideo, Uruguay.
PLoS One. 2023 Aug 17;18(8):e0289984. doi: 10.1371/journal.pone.0289984. eCollection 2023.
Thrips are a serious pest in many crops. In onion cultivation, Thrips tabaci is the most important, but not the only thrips species causing damage. We investigated which thrips species affects onion and related species worldwide, how much genetic variation there is within T. tabaci populations, and how this evolves. Furthermore, we determined the reproductive mode and the correlation between the genetic and geographic distances. Thrips samples from infested onions or related species were obtained from 14 different locations worldwide. Species and haplotypes were determined through DNA barcoding with the mitochondrial Cytochrome Oxidase subunit I (COI) gene. Thrips tabaci was the most commonly observed species, but Scirtothrips dorsalis, Thrips palmi, Frankliniella intonsa, Frankliniella occidentalis and Frankliniella tenuicornis were also found, especially at the beginning of the growing seasons and depending on the location. The Nei's genetic distance within T. tabaci was less than 5% and the haplotypes were clustered into two phylogenetic groups, each linked to a specific mode of reproduction, thelytokous or arrhenotokous. Thelytokous thrips were more common and more widely distributed than arrhenotokous thrips. A high percentage of heteroplasmy was detected in the arrhenotokous group. Heteroplasmic thrips were only found in populations where thelytokous and arrhenotokous were present in sympatry. Some T. tabaci haplotypes were present in high frequency at several sampled locations. No correlation was found between the genetic and geographic distances, which points to anthropic activities spreading thrips haplotypes throughout the world.
蓟马是许多作物的严重害虫。在洋葱种植中，烟蓟马是最重要的，但不是唯一造成损害的蓟马物种。我们研究了哪些蓟马物种影响洋葱和相关物种，在烟蓟马种群中有多少遗传变异，以及这种变异是如何进化的。此外，我们还确定了繁殖方式以及遗传和地理距离之间的相关性。从全球 14 个不同地点采集受感染洋葱或相关物种的蓟马样本。通过线粒体细胞色素氧化酶亚基 I (COI)基因的 DNA 条形码确定物种和单倍型。烟蓟马是最常见的观察物种，但也发现了西花蓟马、棕榈蓟马、温室蓟马、美洲斑潜蝇和短角管蓟马，尤其是在生长季节开始时，且取决于地点。烟蓟马内的 Nei 遗传距离小于 5%，单倍型聚类为两个系统发育群，每个群与特定的繁殖方式（产雌孤雌生殖或产雄孤雌生殖）相关。产雌孤雌生殖的蓟马比产雄孤雌生殖的蓟马更为常见且分布更广。在产雄孤雌生殖组中检测到了很高比例的异质体。异质体蓟马仅在产雌孤雌生殖和产雄孤雌生殖共存的种群中发现。一些烟蓟马单倍型在几个采样地点的出现频率很高。遗传和地理距离之间没有相关性，这表明人为活动将蓟马单倍型传播到世界各地。
