Species in section Peltidea ( aphthosa group) of the genus Peltigera remain cryptic after molecular phylogenetic revision

Plant and Fungal Systematics

article

Jolanta Miadlikowska¹  Nicolas Magain¹  Carlos J. Pardo-De la Hoz¹  Dongling Niu²  Trevor Goward³  Emmanuël Sérusiaux⁴  François Lutzoni¹ 

[1] Department of Biology, Duke University;Life Science School, Ningxia University, Yinchuan;UBC Herbarium, Beaty Museum, University of British Columbia;Evolution and Conservation Biology, University of Liège

关键词: cyanolichen;    molecular systematics;    morphospecies;    Nostoc;    phylogeny;    species;    delimitation;    specificity;    symbiosis;   

DOI  :  10.2478/pfs-2018-0007

来源: Walter de Gruyter GmbH

【 摘 要 】

Closely related lichen-forming fungal species circumscribed using phenotypic traits (morphospecies) do not always align well with phylogenetic inferences based on molecular data. Using multilocus data obtained from a worldwide sampling, we inferred phylogenetic relationships among five currently accepted morphospecies of Peltigera section Peltidea (P. aphthosa group). Monophyletic circumscription of all currently recognized morphospecies (P. britannica, P. chionophila, P. frippii and P. malacea) except P. aphthosa, which contained P. britannica, was confirmed with high bootstrap support. Following their re-delimitation using bGMYC and Structurama, BPP validated 14 putative species including nine previously unrecognized potential species (five within P. malacea, five within P. aphthosa, and two within P. britannica). Because none of the undescribed potential species are corroborated morphologically, chemically, geographically or ecologically, we concluded that these monophyletic entities represent intraspecific phylogenetic structure, and, therefore, should not be recognized as new species. Cyanobionts associated with Peltidea mycobionts (51 individuals) represented 22 unique rbcLX haplotypes from five phylogroups in Clade II subclades 2 and 3. With rare exceptions, Nostoc taxa involved in trimembered and bimembered associations are phylogenetically closely related (subclade 2) or identical, suggesting a mostly shared cyanobiont pool with infrequent switches. Based on a broad geographical sampling, we confirm a high specificity of Nostoc subclade 2 with their mycobionts, including a mutualistically exclusive association between phylogroup III and specific lineages of P. malacea.

【 授权许可】

Unknown