2003年首次在云南昆明发现Q型烟粉虱Bemisia tabaci (Gennadius)传入中国。随后几年时间内, 它在许多省份逐年取代了B型烟粉虱种群。2008年后,Q型烟粉虱基本上成为了中国多数省份农区的优势生物型。为了进一步揭示Q型烟粉虱在中国快速扩散以及取代B型烟粉虱的遗传学基础, 本研究利用11个微卫星位点分析并比较了2003年中国云南昆明Q型烟粉虱入侵种群及其他地点的11个B型入侵种群, 西班牙2个Q型土著种群, 以色列1个Q型入侵种群, 以色列1个B型土著种群, 以及西班牙、 美国与澳大利亚的5个B型入侵种群的遗传结构。结果表明, 中国Q型烟粉虱早期种群(云南昆明种群)可能来自于西部地中海地区。中国B型烟粉虱种群遗传多样性高于西班牙、 澳大利亚、 美国B型种群, 中国B型可能存在多次传入或某个混合种群的再次传入。相对于原产地种群, 中国Q型烟粉虱早期入侵种群与B型烟粉虱种群遗传多样性并没有明显降低, 表明Q型与B型烟粉虱种群可能经历了较小的瓶颈效应或奠基者效应。中国Q型烟粉虱早期入侵种群遗传多样性高于B型烟粉虱种群, Q型烟粉虱这种较高的遗传多样性可能为其较强的生态适应性提供了遗传基础, 有利于Q型烟粉虱在新的环境下快速扩散并取代B型烟粉虱。
The invasive Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) biotype Q (hereafter referred to as Q) was first detected in China in 2003, it gradually displaced the well-established biotype B (hereafter referred to as B) and has become the dominant whitefly in China by 2008. The goal of the current study was to provide insight into the rapid invasion of B. tabaci Q and the domination of B. tabaci Q over B in China. In this study we used 11 microsatellite loci to analyze and compare the genetic structure of one Q and 11 B introduced populations collected in China in 2003 with those of two native Q populations from Spain, one invasive Q population and one native B population from Israel, and five introduced B populations from Spain, the USA, and Australia. The results revealed that the first B. tabaci Q population in China was probably introduced from the western Mediterranean region rather than from the eastern Mediterranean region. The 11 B. tabaci B populations in China, however, might be the progeny of multiple primary introductions from the source region or represent secondary spread from an invaded region. Chinese B had greater genetic diversity than B from Spain, Australia, and the USA, suggesting that Chinese B might have more than one source. Both the first-introduced Chinese Q population and the well-established B populations have not experienced a substantial decrease in genetic diversity relative to their source populations, suggesting minimal bottleneck or founder effects. Genetic diversity for the invasive Q population was greater than the B populations in China, which might contribute to Q’s strong ecological adaptability to the new environments in the introduced regions and thus might explain why it has rapidly spread and displaced the well-established B populations in China.