Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, 60325 Frankfurt am Main, Germany.
Departamento de Biología Vegetal II, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain.
Mol Phylogenet Evol. 2014 Mar;72:54-60. doi: 10.1016/j.ympev.2013.12.010. Epub 2014 Jan 8.
Trebouxia decolorans is a widespread and common symbiotic green alga that is found in association with different species of lichen-forming fungi. By applying T. decolorans-specific microsatellite markers, we investigated the within-thallus diversity of T. decolorans in thalli of Xanthoria parietina and Anaptychia ciliaris. We found several algal strains in most of the thalli of both hosts. High genetic differentiation among thalli suggests that algal diversity is generated de novo via mutation in both fungal hosts. Rarefied allelic richness of the algae was higher in thalli of X. parietina. Our results indicate that in X. parietina intrathalline algal diversity is additionally created by environmental uptake of algae either at the start of the symbiotic association or during the lifetime of the thallus. This study indicates that promiscuous host-symbiont associations in lichen symbioses with Trebouxia spp. may be more common than currently recognized.
褪色栅藻是一种广泛存在且常见的共生绿藻，与不同种的地衣真菌形成共生关系。通过应用特有的褪色栅藻微卫星标记，我们调查了叶状地衣鳞片叶状石黄衣和树花属中的褪色栅藻的叶内多样性。我们在两种宿主的大多数叶状体中发现了几个藻株。叶状体之间的高遗传分化表明，藻的多样性是通过真菌宿主中的突变从头产生的。叶状鳞片叶状石黄衣的藻类稀少等位基因丰富度更高。我们的结果表明，在地衣共生体中，叶状鳞片叶状石黄衣中的叶内藻多样性还可以通过在共生关系开始或叶状体生命周期中环境摄取藻类来额外产生。本研究表明，与 Trebouxia spp.共生的地衣共生体中混杂的宿主-共生体关系可能比目前所认识的更为普遍。
