首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
Abstract:A taxonomic revision of the lichen genus Gymnoderma Nyl. sensu Yoshimura & Sharp (Cladoniaceae) based on an integrative analysis of polyphasic characters supports the segregation of a new genusCetradonia J.-C.Wei & Ahti in a new family Cetradoniaceae J.-C.Wei & Ahti. The monotypic genus and family are based on Cladonia linearis Evans. In addition, two species are recognized in genus Neophyllis F. Wilson and two species are retained in the genus Gymnoderma Nyl. of the Cladoniaceae.  相似文献   

2.
Silicified fossils from Rhynie cherts in Scotland are studied. A lichen belonging to the genus Winfrenatia is detected and studied. This oldest terrestrial lichen is dated to the Pragian (=Siegenian) of the Early Devonian. New characters of the lichen are described, and their new interpretation is given. The main component of the lichen thallus is a filamentous cyanobacterium (Nostocales). Structures which were interpreted as fungal hyphae are probably hollow sheaths of this cyanobacterium. Mycobiont hyphae develop at the base of the thallus and symbiose with a coccoid cyanobacterium. Thus, Winfrenatia reticulata is a three-parted organism, constituted of a mycobiont and filamentous and coccoid cyanobacteria.  相似文献   

3.
Abstract: The lichen symbiosis has evolved several times within the fungal kingdom, although the total number of lichenization events leading to extant taxa is still unclear. Two lichenized families, theIcmadophilaceae and Baeomycetaceae have been classified in the Helotiales. Because the Helotiales are predominantly non-lichenized, this suggests that these families represent independent evolutionary episodes of lichenization from the Lecanorales. As a first step towards understanding the evolution of the lichen symbiosis within this order, we tested recent hypotheses concerning the segregation of lichen genera between the two lichen families. Specifically, we used phylogenetic analyses of nucleotide sequence data from nuclear small-subunit and large-subunit ribosomal DNA to test the morphology-based hypotheses thatDibaeis is a distinct genus from Baeomyces and that Dibaeis is a member of the Icmadophilaceae rather than the Baeomycetaceae. Phylogenetic analyses of nuclear SSU rDNA and combined SSU and LSU rDNA data support the hypothesis that Dibaeis is more closely related to Icmadophila than it is to Baeomyces. Therefore, these data support the resurrection of Dibaeis from its previous synonymy with Baeomyces based on the characters of ascocarp colour and ascus morphology. The recognition of two distinct genera is also consistent with character state distribution of unique lichen acids.  相似文献   

4.
In a lichen sample collected from a tree in Bârlad town (Vaslui County, Romania), a new tardigrade species belonging to the genus Milnesium (granulatum group) was found. Milnesium berladnicorum sp. n. is most similar (in the type of dorsal sculpture) to Milnesium beasleyi Kaczmarek et al., 2012 but differs from it mainly by having a different claw configuration and some morphometric characters. Additionally, the new species differs from other congeners of the granulatum group by the different type of dorsal sculpture, claw configuration and some morphometric characters.  相似文献   

5.
Abstract:Nimisia fuegiae Kärnef. & Thell gen. et sp. nov. is described from Argentinian Tierra del Fuego. The new lichen differs from possibly related groups within the Parmeliaceae in unique anatomical characters, i.e. a medullary layer composed of extremely thick and strongly gelatinized periclinally arranged hyphae and a lower cortex composed of only a few layers of strongly pigmented, rather large cells. Ascus characters support its position in the Parmeliaceae. The new genus, which is named in the honour of its first discoverer, is discussed in relation to several other well-investigated members of the family.  相似文献   

6.
Abstract: The new lichen genus Musaespora is described from Java and Papua New Guinea. It is the first known pyrenocarpous lichen genus with campylidia, and appears to belong to the Aspidotheliaceae. Three species are described, two foliicolous species from Papua New Guinea and one corticolous species from Java. In addition, a list is given of the foliicolous lichen flora of the site in Papua New Guinea, where the foliicolous Musaespora species have been found, two more new foliicolous species are described, Echinoplaca hispida and Sporopodium lucidum, and 19 species are recorded for the first time form Papua New Guinea.  相似文献   

7.
Recent DNA sequence analyses have revealed the diversity of algal partners in lichen symbioses. Although morphologically similar, different genetic lineages of photobionts are detected in wide geographic ranges of the same lichen fungal species. We studied the photobiont of the genus Trebouxia, which are known as partners of diverse lichen-forming fungal species in the Mediterranean region. We studied the phylogeny of these algae with a multilocus dataset including three loci: ITS, rbcL, and actin type I gene. The two lineages found, informally named Trebouxia sp. 1 and Trebouxia sp. 2, are related to Trebouxia arboricola/decolorans. The cultivation under axenic conditions succeeded only for one of them so far. We used light microscopy, confocal laser scanning microscopy and transmission electron microscopy for phenotypic characterisation. The ultrastructural characters currently used to describe species in the genus do not support the segregation of Trebouxia sp.1 from Trebouxia arboricola. The preferential presence in Mediterranean climates of these strains suggests eco-physiological adaptation. Despite their asexuality in long living lichen symbioses, coccoid algal lichen partners have apparently diversified genetically and physiologically.  相似文献   

8.
9.
The systematic position of the lichen genus Heppia in the order Lichinales was investigated. 18S rDNA sequence data were analyzed using a Bayesian approach to infer phylogeny using Markov chain Monte Carlo methods. The Lichinales are divided at family level into the sister groups Lichinaceae and Peltulaceae. The genus Heppia forms a highly supported clade in the family Lichinaceae. It is shown that the genus Heppia is morphologically well circumscribed within the Lichinaceae. As a nomenclatural consequence, the family name Heppiaceae is placed into synonymy under the older name Lichinaceae.  相似文献   

10.
Phylogenetic studies indicate that the basidiolichen genus Dictyonema s.lat., often thought to represent only a single genus with few species, includes several well-supported genus-level clades, all of which form associations with a unique lineage of obligately lichenized cyanobacteria (Rhizonema). In an attempt to elucidate the evolution and genus- and species-level diversification in Dictyonema s.lat., we generated 68 new sequences of the nuclear large subunit rDNA (nuLSU), the internal transcribed spacer (ITS), and the RNA polymerase II subunit (RPB2), for 29 species-level lineages representing all major clades of Dictyonema s.lat. and most of the species currently known. The multilocus phylogeny obtained via maximum likelihood and Bayesian approaches indicates the presence of five genus-level groups: a basal clade, Cyphellostereum, that is sister to the rest of the species, a paraphyletic grade representing Dictyonema s.str., and three clades representing the genera Acantholichen, Cora, and Corella. To determine the evolutionary transformations of the lichenized thallus in the group, ancestral character state reconstruction was done using six characters (lichenisation, thallus type, cortex type, hyphal sheath and haustorial type, photobiont morphology, and basidiocarp type). Our analysis indicates a progressive development of the lichenized thallus from loosely organized filamentous crusts with separate, cyphelloid basidiocarps in Cyphellostereum, to filamentous crusts with derived hyphal sheath and cyphelloid–stereoid basidiocarps partially incorporated into the lichen thallus in Dictyonema, to squamulose–foliose thalli with corticioid basidiocarps entirely supported by the lichen thallus in Cora. These results indicate a remarkable evolutionary integration of lichenized and reproductive tissues in Dictyonema s.lat., supporting the hypothesis that, at least in this case, lichenized thalli may have evolved from reproductive structures in their nonlichenized ancestors.  相似文献   

11.
12.
Abstract:The lichen genus Calycidium Stirt. (Calycidiaceae,Lecanorales , ‘Caliciales’ s. lat.) contains two species: C. cuneatum Stirt., distributed in Australia (Tasmania) and New Zealand, and C. polycarpum (Colenso) Wedin, comb. nov., distributed in Argentina, Australia (Tasmania), Chile and New Zealand. The morphology, chemistry, ecology and distribution of the two species is discussed, as is the taxonomic position of the genus. Calycidium is reported as new to Argentina.  相似文献   

13.
The structure of the associated bacterial community of bipartite cyanolichens of the genus Peltigera from three different environmental contexts in the Karukinka Natural Park, Tierra del Fuego, Chile, was assessed. The sampling sites represent different habitat contexts: mature native forest, young native forest and grassland. Recently it has been determined that the bacterial community associated to lichens could be highly structured according to the mycobiont or photobiont identities, to the environmental context and/or to the geographic scale. However, there are some inconsistencies in defining which of these factors would be the most significant on determining the structure of the microbial communities associated with lichens, mainly because most studies compare the bacterial communities between different lichen species and/or with different photobiont types (algae vs. cyanobacteria). In this work bipartite lichens belonging to the same genus (Peltigera) symbiotically associated with cyanobacteria (Nostoc) were analyzed by TRFLP to determine the structure of the bacterial community intimately associated with the lichen thalli and the one present in the substrate where they grow. The results indicate that the bacterial community intimately associated differs from the one of the substrate, being the former more influenced by the environmental context where the lichen grows.  相似文献   

14.
本文报道了主要分布于澳洲的扇盘衣属地衣,缝裂扇盘衣在中国的首次发现,从而为中国地衣区系增加了一个新记录属。文中报道的该属的地衣不仅在中国,即使在世界范围也十分珍异。因而,对于该属及种的特征从形态学、解剖学与化学方面给以简要描述。  相似文献   

15.
The view of lichens as a symbiosis only between a mycobiont and a photobiont has been challenged by discoveries of diverse associated organisms. Specific basidiomycete yeasts in the cortex of a range of macrolichens were hypothesized to influence the lichens' phenotype. The present study explores the occurrence and diversity of cystobasidiomycete yeasts in the lichen genus Cladonia. We obtained seven cultures and 56 additional sequences using specific primers from 27 Cladonia species from all over Europe and performed phylogenetic analyses based on ITS, LSU and SSU rDNA loci. We revealed yeast diversity distinct from any previously reported. Representatives of Cyphobasidiales, Microsporomycetaceae and of an unknown group related to Symmetrospora have been found. We present evidence that the Microsporomycetaceae contains mainly lichen-associated yeasts. Lichenozyma pisutiana is circumscribed here as a new genus and species. We report the first known associations between cystobasidiomycete yeasts and Cladonia (both corticate and ecorticate), and find that the association is geographically widespread in various habitats. Our results also suggest that a great diversity of lichen associated yeasts remains to be discovered.  相似文献   

16.
Abstract:A characteristic, sterile lichen genus with homoiomerous thallus containing terpenoids is described, with one subtropical species, Kroswia crystalliferum sp. nov., occurring scattered in Africa from Kenya south to the Cape, southern India (with Sri Lanka) and Taiwan. Another temperate species, Kroswia gemmascens (Nyl.) comb. nov., is restricted to Eastern Asia. In spite of its gelatinous, homoiomerous thallus, the genus appears to belong to thePannariaceae .  相似文献   

17.
Up to the present, the genus Leptostichaeus has been considered as belonging to subfamily Lumpeninae. A series of characters was analyzed for family and subfamily diagnostics within the group Stichaeidae. It was found that, in combination of all examined characters, the genus Leptostichaeus is either similar to Azygopterus or occupies an intermediate position between the latter and other members of the family Stichaeidae. The genus Leptostichaeus is transferred into the group Azygopterinae, which is revalidated as a subfamily within the family Stichaeidae.  相似文献   

18.
19.
20.
The Lower Jurassic genus Eodasycladus is discussed according to the characters of type species and compared with the other species known in the literature. The architecture of two species attributed to the genus Palaeodasycladus, P. alanensis Soka?, and P. benceki Soka?, is examined and an alternative organization of the thallus is prospected. P. alanensis is considered a valid species, but its characters require to transfer the taxon to the genus Eodasycladus. P. benceki is considered synonymous with P. alanensis.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号