Leiva Ana M, Chittarath Khonesavanh, Lopez-Alvarez Diana, Vongphachanh Pinkham, Gomez Maria Isabel, Sengsay Somkhit, Wang Xiao-Wei, Rodriguez Rafael, Newby Jonathan, Cuellar Wilmer J
Cassava Program, Crops for Nutrition and Health, International Center for Tropical Agriculture (CIAT), The Americas Hub, Km 17 Recta Cali-Palmira, Cali 763537, Colombia.
Plant Protection Center (PPC), Department of Agriculture, Ministry of Agriculture and Forestry, Vientiane P.O. Box 811, Laos.
Insects. 2022 Sep 22;13(10):861. doi: 10.3390/insects13100861.
Cassava Mosaic Disease (CMD) caused by Sri Lankan cassava mosaic virus (SLCMV), has rapidly spread in Southeast Asia (SEA) since 2016. Recently it has been documented in Lao PDR. Previous reports have identified whitefly species of as potential vectors of CMD in SEA, but their occurrence and distribution in cassava fields is not well known. We conducted a countrywide survey in Lao PDR for adult whiteflies in cassava fields, and determined the abundance and genetic diversity of the species complex using mitochondrial cytochrome oxidase I (mtCOI) sequencing. In order to expedite the process, PCR amplifications were performed directly on whitefly adults without DNA extraction, and mtCOI sequences obtained using nanopore portable-sequencing technology. Low whitefly abundances and two cryptic species of the complex, Asia II 1 and Asia II 6, were identified. This is the first work on abundance and genetic identification of whiteflies associated with cassava in Lao PDR. This study indicates currently only a secondary role for Asia II in spreading CMD or as a pest. Routine monitoring and transmission studies on Asia II 6 should be carried out to establish its potential role as a vector of SLCMV in this region.
由斯里兰卡木薯花叶病毒（SLCMV）引起的木薯花叶病（CMD）自2016年以来在东南亚迅速蔓延。最近在老挝人民民主共和国有相关记录。此前的报告已确定粉虱物种是东南亚CMD的潜在传播媒介，但其在木薯田中的发生情况和分布尚不清楚。我们在老挝人民民主共和国对木薯田中的成年粉虱进行了全国性调查，并使用线粒体细胞色素氧化酶I（mtCOI）测序确定了该物种复合体的丰度和遗传多样性。为了加快进程，直接对粉虱成虫进行PCR扩增而不进行DNA提取，并使用纳米孔便携式测序技术获得mtCOI序列。确定了粉虱丰度较低，以及该复合体的两个隐性物种，即亚洲II 1和亚洲II 6。这是老挝人民民主共和国首次关于与木薯相关的粉虱丰度和遗传鉴定的研究。这项研究表明，目前亚洲II在传播CMD或作为害虫方面仅起次要作用。应对亚洲II 6进行常规监测和传播研究，以确定其在该地区作为SLCMV传播媒介的潜在作用。
