广东首次发现Q型烟粉虱种群分布

The first record of a cryptic Bemisia tabaci MED species in Guangdong

烟粉虱Bemisia tabaci（Gennadius）是全世界分布的刺吸式传毒昆虫，其中Q型烟粉虱自2003年首次在昆明一品红上发现以来，该种群已在全国10多个省份广泛传播，并有逐步取代B型烟粉虱的趋势。然而，作为较早对外开放的沿海省份，广东省一直未有Q型烟粉虱在田间分布危害的报道。本文利用常规PCR、特异B／Q型烟粉虱引物扩增及DNA测序技术，对近期在广州长’碰公园扶桑寄主上采集的烟粉虱种群进行了分子鉴定，并对该种群与国内外其它Q型种群的系统发育关系进行了研究。结果表明，在广州长、碰公园扶桑寄主上采集的烟粉虱种群为Q型烟粉虱，在660bp的mtCOI序列中，该Q型烟粉虱与来自江苏、云南及浙江的Q型烟粉虱种群分别有1—2个碱基差异；系统进化关系表明该Q型烟粉虱与江苏、云南的Q型烟粉虱最近，其种群的最初起源应为地中海西岸地区。相比B型烟粉虱，Q烟粉虱被认为具有更强的抗药性和传播植物病毒的能力，Q型烟粉虱在广东的首次发现，表明该烟粉虱种群已在广东野外定殖，其扩散动态、寄主范围及危害程度亟待实时监测。

The whitefly Bemisia tabaci （Gennadius） is a globally distributed, phloem-feeding insect that transmits more than 110 plant viruses. Since its first record in China on Poinsettia in Kunming in 2003, the B. tabaci Q biotype （belonging to a Mediterranean cryptic species） has been found to have spread to more than 10 provinces, gradually replacing the B biotype （MEAM1 cryptic species）. However, the B. tabaci Q biotype had not been reported in Guangdong, a Province with a large volume of internal and international trade. However, a population of the Q biotype was recently identified from specimens collected from a hibiscus plant in Changban Park, Guangzhou City. PCR and DNA sequencing using B/Q biotype primers revealed that this population is 1-2 base pairs different from known Q biotype populations in Yunnan, Jiangsu and Zhejiang provinces. Neighbour-joining phylogenetic tree analysis indicates that this Guangzhou Q biotype is closer to the Q biotype populations in Yunnan and Jiangsu provinces, and that it is probably of western Mediterranean, Greece, Spain, Morocco etc. The B. tabaci Q biotype is considered to have higher resistance to chemicals and a greater ability to transmit plant viruses. The first record of this pest in Guangzhou could indicate that this pest is already well established in this Province. Further investigation is required to monitor its spread, host plants and damage.