Scataglini María A, Lanteri Analia A, Confalonieri Viviana A
Departamento de Ecología, Genética y Evolución, Fac. Cs. Exactas y Naturales, UBA, Ciudad Universitaria, 1428, Buenos Aires, Argentina.
Genetica. 2006 Mar;126(3):353-68. doi: 10.1007/s10709-005-1399-2.
A phylogeographic approach was conducted to assess the geographic structure and genetic variation in populations of the boll weevil Anthonomus grandis, which is the most harmful insect pest of cotton in the Americas. COI and COII mitochondrial gene sequences were analyzed to test a former hypothesis on the origin of the boll weevil in Argentina, Brazil and Paraguay, using samples from Mexico and USA as putative source populations. The analysis of variability suggests that populations from South American cotton fields and nearby disturbed areas form a phylogroup with a central haplotype herein called A, which is the most common and widespread in USA and South America. The population from Texas has the A haplotype as the most frequent and gathers in the same group as the South American populations associated with cotton. The sample from Tecomán (México) shows high values of within-nucleotide divergence, shares no haplotype in common with the South American samples, and forms a phylogroup separated by several mutational steps. The sample from Iguazú National Park (Misiones Province, Argentina) has similar characteristics, with highly divergent haplotypes forming a phylogroup closer to the samples from cotton fields, than to the Mexican group. We propose that in South America there are: populations with characteristics of recent invaders, which would be remnants of "bottlenecks" that occurred after single or multiple colonization events, probably from the United States, and ancient populations associated with native forests, partially isolated by events of historical fragmentation.
采用系统发育地理学方法评估棉铃象甲（Anthonomus grandis）种群的地理结构和遗传变异，棉铃象甲是美洲最具危害性的棉花害虫。分析了细胞色素氧化酶亚基I（COI）和细胞色素氧化酶亚基II（COII）线粒体基因序列，以检验先前关于阿根廷、巴西和巴拉圭棉铃象甲起源的假设，使用来自墨西哥和美国的样本作为假定的源种群。变异性分析表明，来自南美棉田及附近受干扰地区的种群形成一个单倍型类群，其中心单倍型在此称为A，该单倍型在美国和南美最为常见且分布广泛。得克萨斯州的种群中A单倍型最为常见，并与和棉花相关的南美种群聚集在同一类群中。来自特科曼（墨西哥）的样本显示出较高的核苷酸内差异值，与南美样本没有共同的单倍型，且形成一个由几个突变步骤分隔的单倍型类群。来自伊瓜苏国家公园（阿根廷米西奥内斯省）的样本具有相似特征，高度分化的单倍型形成一个比墨西哥类群更接近棉田样本的单倍型类群。我们提出，在南美存在：具有近期入侵者特征的种群，可能是单次或多次殖民事件（可能来自美国）后发生的“瓶颈”的残余，以及与原生森林相关的古老种群，它们因历史片段化事件而部分隔离。
