A new species of <Emphasis Type="Italic">Ophiodothella</Emphasis> on <Emphasis Type="Italic">Casearia</Emphasis> from Venezuela

 Ophiodothella caseariae sp. nov. from leaves of Casearia tremula in Venezuela is described and illustrated. Received: February 19, 2002 / Accepted: April 30, 2002     

海南炭角新种

在海南省炭角菌的调查研究中,发现一个生长于枯死落叶上的炭角菌属新种。它子座单个,顶端不孕,针刺状,柄细长,多毛,表面呈灰色,有圆锥状孔口。子囊壳埋生。通过与其他9种叶生炭角菌进行比较,确定为海南炭角菌 Xylaria hainanensis新种。     

Hypoxyvermelhotins A–C,new pigments from Hypoxylon lechatii sp. nov

A new species of Hypoxylon was discovered, based on material collected in French Guiana and recognised on the basis of new combination of morpholological characters in comparison with type and authentic material of macroscopically similar taxa. These findings were corroborated by the rather isolated positions of its ITS-nrDNA and beta-tubulin DNA sequences in molecular phylogenies. However, the most salient feature of this fungus only became evident by a comparison of its stromatal HPLC profile, revealing several secondary metabolites that were hitherto not observed in stromata of any other member of the Xylariaceae. Part of the stromata were subsequently extracted to isolate these apparently specific components, using preparative chromatography. Five metabolites were obtained in pure state, and their chemical structures were elucidated by means of high resolution mass spectrometry and nuclear magnetic resonance spectroscopy. They turned out to be tetramic acid derivatives of the so-called vermelhotin type. Aside from vermelhotin, previously isolated from cultures of endophytic fungi, we identified three novel congeners, for which the trivial names hypoxyvermelhotins A–C were proposed. Like vermelhotin, they constitute orange-red pigments and a preliminary biological characterisation revealed them to have rather strong cytotoxic and moderate to weak antimicrobial effects. These results further illustrate the high diversity of unique secondary metabolites in stromata of the hypoxyloid Xylariaceae, a family in which biological diversity seems to parallel the chemical diversity of their bioactive principles to a great extent.     

Pandanicola graminella comb. nov. fromFestuca filiformis in the Canary Islands, West Africa

Anthostomella graminella has been re-examined and ascomata were found to be immersed beneath a clypeus. Asci were unitunicate, broad cylindrical, and lacked an apical apparatus, while ascospores were inequilaterally ellipsoidal, 1–2 seriate, brown to light brown and unicellular, with bipolar germ pores. Based on these characters,A. graminella is transferred toPandanicola. An illustration of this species and a tabulated comparison of this species withPandanicola calocarpa is given.     

Are endophytic fungi from Rhododendron tomentosum preadapted for its essential oil?

Endophytic fungi have to cope with various secondary metabolites produced by their host plant. Rhododendron tomentosum is an evergreen shrub with a high content of essential oil showing antimicrobial effects. The first aim of our study was to reveal the diversity of culturable endophytic fungi colonizing leaves of R. tomentosum. We isolated and identified 30 species, mostly ubiquitous species colonizing various plants as endophytes and later turning into saprotrophs. The second aim was to explore whether strains obtained from R. tomentosum (RT-strain) are better adapted to growth in environments with essential oils, compared to strains of the same species obtained from different substrates. In five of the six species pairs tested, the growth of RT-strains was more inhibited by three components of the essential oil added to the medium, compared to the corresponding strains. Only the RT-strain of Desmazierella acicola was less susceptible compared to its corresponding strain. Our results show that the essential oil in leaves of R. tomentosum do not represent a selective barrier that can be crossed only by preadapted strains.     

Ceratostomella hyalocoronata, a new pyrenomycete from a stream in southern China

Ceratostomella hyalocoronata is described and illustrated as a new species from old decaying wood immersed in a stream in Guangdong Province, southern China. It is compared toC. hyalostoma, a temperate terrestrial species.     

A new species of Ophiodothella on Casearia from Venezuela

Ophiodothella caseariae sp. nov. from leaves of Casearia tremula in Venezuela is described and illustrated.