PDF(Pubmed)
Abstract：
Within the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) complex, two cryptic species, namely Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED), are important invasive pests affecting global agriculture and horticulture. They were introduced into China sequentially in the mid-1990s and around 2003, respectively. Subsequently, the latter invader MED has outcompeted the earlier invader MEAM1, becoming the dominant population in the field. Although extensive studies have explored the underlying mechanisms driving this shift, the contribution of population genetics remains notably underexplored. In this study, we analyzed the genetic diversity and structure of 22 MED and 8 MEAM1 populations from various regions of China using mitochondrial DNA sequencing and microsatellite genotyping. Our results indicate low and moderate levels of genetic differentiation among geographically separate populations of MED and MEAM1, respectively. Median-joining network analysis of mtCOI gene haplotypes revealed no clear geographic structuring for either, with common haplotypes observed across provinces, although MED had more haplotypes. Comparative analyses revealed that MED presented greater genetic diversity than MEAM1 on the basis of two markers. Furthermore, analysis of molecular variance supported these findings, suggesting that while some genetic variation exists between populations, a significant amount is also present within populations. These findings reveal the population genetics of the two invasive cryptic species of the B. tabaci complex in China and suggest that the disparities in genetic diversity drive the displacement of their populations in the field. This work also provides valuable information on the genetic factors influencing the population dynamics and dominance of these invasive whitefly species.
摘要：
在粉虱烟粉虱（Gennadius）（半翅目：Aleyrodidae）复合体中，两个神秘的物种，即中东-亚洲小牛1（MEAM1）和地中海（MED），是影响全球农业和园艺的重要入侵害虫。它们分别于1990年代中期和2003年左右相继引入中国。随后，后者的入侵者MED胜过了较早的入侵者MEAM1，成为该领域的主要人口。尽管广泛的研究已经探索了推动这一转变的潜在机制，群体遗传学的贡献仍然显着不足。在这项研究中,我们利用线粒体DNA测序和微卫星基因分型技术分析了来自中国不同地区的22个MED和8个MEAM1群体的遗传多样性和结构。我们的结果表明，在地理上不同的MED和MEAM1种群之间，遗传分化水平分别较低和中等。mtCOI基因单倍型的中值加入网络分析显示，两者都没有明确的地理结构，在各省观察到常见的单倍型，尽管MED有更多的单倍型。比较分析表明，基于两个标记，MED比MEAM1具有更大的遗传多样性。此外，分子方差分析支持这些发现，这表明虽然种群之间存在一些遗传变异，大量也存在于人群中。这些发现揭示了中国烟粉虱两种入侵隐秘物种的种群遗传学，并表明遗传多样性的差异驱动了其种群在野外的流离失所。这项工作还提供了有关影响这些入侵粉虱物种种群动态和优势的遗传因素的宝贵信息。
