煙草粉蝨 (Bemisia tabaci (Gennadius))是一種泛世界性分佈之重要農業害蟲，危害方式是以刺吸式口器攝食植物汁液導致植株衰弱，分泌蜜露誘發煤煙病及傳播植物病毒危害宿主植物。臺灣番茄捲葉病毒(Tomato leaf curl Taiwan virus, ToLCTWV)由煙草粉蝨所傳播，並在臺灣地區造成番茄作物的嚴重損失。本研究全面採集臺灣地區番茄作物上的煙草粉蝨，利用聚合酶連鎖反應(polymerase chain reaction, PCR)增幅ToLCTWV鞘蛋白基因(coat protein, CP)來進行偵測及調查其分佈狀態。臺灣地區目前有四型煙草粉蝨生物小種分佈，序列特徵化增幅區域(sequence characterized amplified region, SCAR)被應用來鑑定生物小種。偵測結果顯示帶有ToLCTWV的均為B型生物小種。序列相似度、親緣關係及親緣地理分析結果顯示，ToLCTWV分為臺灣東部與西部兩個變異株(variant)，東部變異株(ETW)源自於西部變異株(WTW)。西部變異株由於變異小加上人為傳播，使得西部各地的ToLCTWV關係難以探討；東部變異株變異大，可能是由於地形、氣候因素及人為干擾小。根據遺傳變異推測東部變異株在東部由南方往北方擴散。
Bemisia tabaci (Gennadius) is an important global agricultural pest. The economic impacts of this pest are primarily due to the damage it inflicts on the health of the host plant health by sucking the plant's juices, by fouling the life cycle of the plant, by secreting honeydew, and by transmitting plant viruses. The most serious damage caused by B. tabaci is its transmission of the Tomato leaf curl Taiwan virus (ToLCTWV) to tomato plants in Taiwan. In this study, B. tabaci was collected from tomato fields in Taiwan, and the coat protein (CP) gene of the ToLCTWV was isolated from B. tabaci by polymerase chain reaction (PCR). Four biotypes of B. tabaci have been recorded in Taiwan, and the sequence characterized amplified regions (SCARs) were used to identify the various biotypes. The results revealed that all collected ToLCTWVs were determined to be biotype B of B. tabaci. Analyses of the sequence identity, phylogeny, and phylogeography indicated that the ToLCTWV was separated into two variants (a western Taiwan (WTW) variant and an eastern Taiwan (ETW) variant), and that the ETW variant originated from the WTW variant. Phylogenetic relationship within the WTW variant was difficult to discern because of the low genetic variation and its high level of human trade activities. The ETW variant had a higher genetic variance because of its topography, climate, and its low level of human trade activities. The genetic variations suggest that the ETW variant dispersed from the south to northeastern Taiwan.
