University of Greifswald, Institute of Botany and Landscape Ecology, Greifswald, Germany.
PLoS One. 2011;6(8):e22872. doi: 10.1371/journal.pone.0022872. Epub 2011 Aug 1.
Plasmodial slime molds (Myxogastria or Myxomycetes) are common and widespread unicellular organisms that are commonly assumed to have a sexual life cycle culminating with the formation of often macroscopic fruiting bodies that efficiently disseminate spores. However, laboratory studies based on mating compatibility revealed the coexistence of asexual as well as sexual strains. To test this hypothesis in natural populations, we investigated the genetic variability of two species of the genus Lamproderma. Detailed ecological relevés were carried out in 2007 and 2009 in several deep ravines in the Elbsandsteingebirge (Saxony, south-eastern Germany). Morphological characters of 93 specimens of Lamproderma were recorded and genetic analyses, based on the small subunit ribosomal gene, the internal transcribed spacer 1 and partial elongation factor 1α sequences were carried out for 52 specimens. Genetic analyses showed the existence of two major clades, each composed of several discrete lineages. Most of these lineages were composed of several identical sequences (SSU, ITS 1 and EF-1α) which is explained best by an asexual mode of reproduction. Detrended Correspondence Analysis of morphological characters revealed two morphospecies that corresponded to the two major clades, except for one genotype (Lc6), thus challenging the morphospecies concept. Genetic patterns were not related to the geographical distribution: specimens belonging to the same genotype were found in distinct ravines, suggesting effective long-distance dispersal via spores, except for the Lc6 genotype which was found only in one ravine. Implications for the morphological and biological species concept are discussed.
质体粘菌（Myxogastria 或 Myxomycetes）是常见且广泛分布的单细胞生物，通常被认为具有有性生命周期，最终形成通常是宏观的生殖体，有效地传播孢子。然而，基于交配相容性的实验室研究揭示了无性和有性菌株的共存。为了在自然种群中检验这一假设，我们调查了 Lamproderma 属的两个物种的遗传变异性。2007 年和 2009 年，在萨克森州东南部德国的 Elbsandsteingebirge 的几个深峡谷中进行了详细的生态调查。记录了 93 个 Lamproderma 标本的形态特征，并对 52 个标本进行了基于小亚基核糖体基因、内部转录间隔区 1 和部分延伸因子 1α 序列的遗传分析。遗传分析显示存在两个主要分支，每个分支由几个离散的谱系组成。这些谱系中的大多数由几个相同的序列（SSU、ITS 1 和 EF-1α）组成，这最好通过无性繁殖方式来解释。形态特征的去趋势对应分析揭示了两个与两个主要分支相对应的形态种，除了一个基因型（Lc6），这对形态种概念提出了挑战。遗传模式与地理分布无关：属于同一基因型的标本存在于不同的峡谷中，表明通过孢子进行有效的长距离传播，除了 Lc6 基因型，它只在一个峡谷中发现。讨论了对形态学和生物学种概念的影响。
