Division of EcoScience and Research Institute of EcoScience, Ewha Womans University, Seoul, Republic of Korea.
PLoS One. 2010 Jul 15;5(7):e11608. doi: 10.1371/journal.pone.0011608.
The species-rich genus Aphis consists of more than 500 species, many of them host-specific on a wide range of plants, yet very similar in general appearance due to convergence toward particular morphological types. Most species have been historically clustered into four main phenotypic groups (gossypii, craccivora, fabae, and spiraecola groups). To confirm the morphological hypotheses between these groups and to examine the characteristics that determine them, multivariate morphometric analyses were performed using 28 characters measured/counted from 40 species. To infer whether the morphological relationships are correlated with the genetic relationships, we compared the morphometric dataset with a phylogeny reconstructed from the combined dataset of three mtDNA and one nuclear DNA regions.
Based on a comparison of morphological and molecular datasets, we confirmed morphological reduction or regression in the gossypii group unlike in related groups. Most morphological characteristics of the gossypii group were less variable than for the other groups. Due to these, the gossypii group could be morphologically well separated from the craccivora, fabae, and spiraecola groups. In addition, the correlation of the rates of evolution between morphological and DNA datasets was highly significant in their diversification.
The morphological separation between the gossypii group and the other species-groups are congruent with their phylogenetic relationships. Analysis of trait evolution revealed that the morphological traits found to be significant based on the morphometric analyses were confidently correlated with the phylogeny. The dominant patterns of trait evolution resulting in increased rates of short branches and temporally later evolution are likely suitable for the modality of Aphis speciation because they have adapted species-specifically, rapidly, and more recently on many different host plants.
物种丰富的蚜属由 500 多种组成，其中许多种对多种植物具有专性，由于趋同作用，它们在外观上非常相似。大多数物种在历史上被聚类为四个主要的表型群（棉蚜组、蝗蚜组、豆蚜组和榆叶蜂组）。为了确认这些组之间的形态假说，并研究确定它们的特征，我们使用从 40 个物种中测量/计数的 28 个特征对多变量形态计量分析进行了分析。为了推断形态关系是否与遗传关系相关，我们将形态计量数据集与从三个 mtDNA 和一个核 DNA 区域的组合数据集重建的系统发育进行了比较。
基于形态和分子数据集的比较，我们证实了棉蚜组的形态退化或萎缩，而不是与相关组。棉蚜组的大多数形态特征比其他组的变化更小。由于这些特征，棉蚜组可以与蝗蚜组、豆蚜组和榆叶蜂组在形态上很好地区分开来。此外，形态和 DNA 数据集之间进化速率的相关性在它们的多样化中高度显著。
棉蚜组与其他物种组之间的形态分离与它们的系统发育关系一致。特征进化分析表明，形态计量分析中发现的显著形态特征与系统发育具有可靠的相关性。导致短分支和时间上后期进化的进化特征主导模式很可能适合蚜属物种形成的方式，因为它们在许多不同的宿主植物上具有特异性、快速和最近的适应。
