For the very first time,morpho-anatomical features of both fruiting bodies as well as below-ground structures have been confronted with a newly produced multigene phylogeny of root symbiotic basidiomycetes using one o...For the very first time,morpho-anatomical features of both fruiting bodies as well as below-ground structures have been confronted with a newly produced multigene phylogeny of root symbiotic basidiomycetes using one of the most speciose genera of ectomycorrhizal fungi(Russula,Russulales)as an example.In this first of two papers,the authors focus more specifically on below-ground structures.Our five-gene phylogeny divides the genus in five main clades,here interpreted as representing seven subgenera,all significantly supported.Although more conserved than features of fruiting bodies,the anatomy of ectomycorrhiza does not allow for an unambiguous characterization of the main clades resolved by phylogenetic analysis,but the anatomy of ectomycorrhiza performs better to naturally classify the species of this genus.Features of fruiting bodies remain much more adequate for the delimitation of terminal clades and are irreplaceable for morphological species identification.Tropical taxa mostly nest in ancient lineages,but are also present in some terminal clades of otherwise temperate species groups.The shift from plectenchymatic to pseudoparenchymatic ECM outer mantle structures happened most likely already in the paleotropics,and is here hypothesized to have facilitated a major diversification of the genus with new hosts in the northern hemisphere.Available data as well as our own observations on below ground structures of several Lactifluus species suggests that this genus shares with Russula the absence of lactifers in ECM mantles and rhizomorphs,contrary to species of Lactarius where lactifers are always present.First observations on rhizomorphs of species in Multifurca confirm the presence of vessel-like and ladder-like hyphae,also found in the other agarioid genera of this family,while distinct lactifers are only present in the lactarioid,but not in russuloid members of this genus.展开更多
This paper provides an overview and identification key of the Australasian species of Lactarius subg.Gerardii.A molecular phylogeny based on the nuc DNA markers ITS,LSU and rpb2,combined with detailed morphological ob...This paper provides an overview and identification key of the Australasian species of Lactarius subg.Gerardii.A molecular phylogeny based on the nuc DNA markers ITS,LSU and rpb2,combined with detailed morphological observations resulted in the delimitation of 12 strongly supported and morphologically recognizable species.Five new agaricoid species are described here:Lactarius hora,L.coniculus,L.limbatus,L.leae and L.leonardii.Other agaricoid species belonging to subg.Gerardii are L.atrovelutinus,L.bicolor,L.ochrogalactus and L.reticulatovenosus.Lactarius venosus is also considered as a member but could not be included in the molecular analysis.Two new pleurotoid species are discovered:L.genevievae and L.conchatulus,both close relatives of L.uyedae,but each with distinct characters.Their position within subg.Gerardii is supported in the phylogeny and by their microscopic characters.This study also confirms the existence of multiple cryptic species and species complexes for which species recognition or species delimitation remains problematic as is the case for the Australian species L.wirrabara.In general,detailed macroscopic and microscopic observations are needed to identify species of L.subg.Gerardii.展开更多
文摘For the very first time,morpho-anatomical features of both fruiting bodies as well as below-ground structures have been confronted with a newly produced multigene phylogeny of root symbiotic basidiomycetes using one of the most speciose genera of ectomycorrhizal fungi(Russula,Russulales)as an example.In this first of two papers,the authors focus more specifically on below-ground structures.Our five-gene phylogeny divides the genus in five main clades,here interpreted as representing seven subgenera,all significantly supported.Although more conserved than features of fruiting bodies,the anatomy of ectomycorrhiza does not allow for an unambiguous characterization of the main clades resolved by phylogenetic analysis,but the anatomy of ectomycorrhiza performs better to naturally classify the species of this genus.Features of fruiting bodies remain much more adequate for the delimitation of terminal clades and are irreplaceable for morphological species identification.Tropical taxa mostly nest in ancient lineages,but are also present in some terminal clades of otherwise temperate species groups.The shift from plectenchymatic to pseudoparenchymatic ECM outer mantle structures happened most likely already in the paleotropics,and is here hypothesized to have facilitated a major diversification of the genus with new hosts in the northern hemisphere.Available data as well as our own observations on below ground structures of several Lactifluus species suggests that this genus shares with Russula the absence of lactifers in ECM mantles and rhizomorphs,contrary to species of Lactarius where lactifers are always present.First observations on rhizomorphs of species in Multifurca confirm the presence of vessel-like and ladder-like hyphae,also found in the other agarioid genera of this family,while distinct lactifers are only present in the lactarioid,but not in russuloid members of this genus.
基金The Malaysian expedition was funded by the Foundation of Scientific Research-Flanders(FWO-Vlaanderen)Dirk Stubbe was funded by a scholarship of the Institute for the Promotion of Innovation through Science and Technology(IWT-Vlaanderen)+1 种基金A PEET-grant of the National Science Foundation(USA)(DEB-0118776)to ProfDennis Desjardin and a scholarship of the Chiang Mai University made it possible for Huyen Than Le to conduct her research in Thailand.Xiang-Hua Wang was funded by National Natural Science Foundation of China(NSFC 30970020,30300002).
文摘This paper provides an overview and identification key of the Australasian species of Lactarius subg.Gerardii.A molecular phylogeny based on the nuc DNA markers ITS,LSU and rpb2,combined with detailed morphological observations resulted in the delimitation of 12 strongly supported and morphologically recognizable species.Five new agaricoid species are described here:Lactarius hora,L.coniculus,L.limbatus,L.leae and L.leonardii.Other agaricoid species belonging to subg.Gerardii are L.atrovelutinus,L.bicolor,L.ochrogalactus and L.reticulatovenosus.Lactarius venosus is also considered as a member but could not be included in the molecular analysis.Two new pleurotoid species are discovered:L.genevievae and L.conchatulus,both close relatives of L.uyedae,but each with distinct characters.Their position within subg.Gerardii is supported in the phylogeny and by their microscopic characters.This study also confirms the existence of multiple cryptic species and species complexes for which species recognition or species delimitation remains problematic as is the case for the Australian species L.wirrabara.In general,detailed macroscopic and microscopic observations are needed to identify species of L.subg.Gerardii.
