Singh Garima, Dal Grande Francesco, Werth Silke, Scheidegger Christoph
Department of Biological Sciences, Institute of Ecology, Evolution and Diversity, Goethe Universität, Max-von-Laue-Str. 13, D-60438 Frankfurt, Tel: +49 (0)69 7542 1851; Fax: +49 (0)69 7542 1800, Germany Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, D-60325 Frankfurt, Germany Biodiversity and Conservation Biology, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, D-60325 Frankfurt, Germany.
FEMS Microbiol Ecol. 2015 Jan;91(1):1-11. doi: 10.1093/femsec/fiu009. Epub 2014 Dec 5.
The effect of disturbance on symbiotic organisms such as lichens is particularly severe. In case of heterothallic lichen-forming fungi, disturbances may lead to unbalanced gene frequency and patchy distribution of mating types, thus inhibiting sexual reproduction and imposing clonality. The impact of disturbance on reproductive strategies and genetic diversity of clonal systems has so far received little attention. To infer the effects of disturbances on mating-type allele frequencies and population structure, we selected three populations in the Parc Jurassien Vaudois (Switzerland), which were affected by uneven-aged forestry, intensive logging and fire, respectively. We used microsatellite markers to infer genetic diversity, allelic richness and clonal diversity of the epiphytic lichen Lobaria pulmonaria and used L. pulmonaria-specific MAT1-1 and MAT1-2 markers to analyse the frequency and distribution of mating types of 889 individuals. Our study shows that stand-replacing disturbances affect the mating-type frequency and distribution, thus compromising the potential for sexual reproduction. The fire-disturbed area had a significantly lower genetic and genotypic diversity and a higher clonality. Furthermore, the majority of compatible mating pairs in this area were beyond the effective vegetative dispersal range of the species. We conclude that stand-replacing disturbances lead to lower chances of sex and symbiont reshuffling and thus have long-lasting negative consequences on the reproductive strategies and adaptive potential of epiphytic lichen symbioses.
干扰对诸如地衣等共生生物的影响尤为严重。对于异宗配合的地衣形成真菌而言，干扰可能导致基因频率失衡以及交配型的斑块状分布，从而抑制有性生殖并导致无性繁殖。迄今为止，干扰对克隆系统的繁殖策略和遗传多样性的影响几乎未受到关注。为了推断干扰对交配型等位基因频率和种群结构的影响，我们在瑞士汝拉州沃州自然公园选择了三个分别受到异龄林经营、高强度伐木和火灾影响的种群。我们使用微卫星标记来推断附生地衣肺衣的遗传多样性、等位基因丰富度和克隆多样性，并使用肺衣特有的MAT1-1和MAT1-2标记来分析889个个体的交配型频率和分布。我们的研究表明，导致林分更替的干扰会影响交配型频率和分布，从而损害有性生殖的潜力。火灾干扰区域的遗传和基因型多样性显著较低，而克隆性较高。此外，该区域大多数兼容的交配配对超出了该物种有效的营养体传播范围。我们得出结论，导致林分更替的干扰会降低有性生殖和共生体重新组合的机会，从而对附生地衣共生体的繁殖策略和适应潜力产生长期的负面影响。
