Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.
ISME J. 2013 Oct;7(10):2057-9. doi: 10.1038/ismej.2013.73. Epub 2013 May 9.
Contrary to expectation, populations of clonal organisms are often genetically highly diverse. In phytoplankton, this diversity is maintained throughout periods of high population growth (that is, blooms), even though competitive exclusion among genotypes should hypothetically lead to the dominance of a few superior genotypes. Genotype-specific parasitism may be one mechanism that helps maintain such high-genotypic diversity of clonal organisms. Here, we present a comparison of population genetic similarity by estimating the beta-dispersion among genotypes of early and peak bloom populations of the diatom Asterionella formosa for three spring-blooms under high or low parasite pressure. The Asterionella population showed greater beta-dispersion at peak bloom than early bloom in the 2 years with high parasite pressure, whereas the within group dispersion did not change under low parasite pressure. Our findings support that high prevalence parasitism can promote genetic diversification of natural populations of clonal hosts.
与预期相反，克隆生物的种群通常具有高度的遗传多样性。在浮游植物中，这种多样性在种群高速增长（即水华）期间得以维持，尽管基因型之间的竞争排斥理论上应该导致少数优势基因型的主导地位。基因型特异性寄生可能是有助于维持克隆生物如此高遗传多样性的一种机制。在这里，我们通过在高或低寄生虫压力下的三个春季水华期间，估计早花期和高峰期的菱形藻种群的基因型之间的β-分散度，对种群遗传相似性进行了比较。在高寄生虫压力的 2 年中，菱形藻种群在高峰期的β-分散度大于早期，而在低寄生虫压力下，组内分散度没有变化。我们的研究结果支持高流行寄生虫可以促进克隆宿主的自然种群的遗传多样化。
