Adrian Leuchtmann

ETH Zurich | ETH Zürich · Institute of Integrative Biology Zurich

Species of Epichloë (Ascomycota: Clavicipitaceae), which infect grasses, maintain an obligate symbiotic relationship with flies of the genus Botanophila (Diptera: Anthomyiidae). Sexual reproduction of the fungus usually requires a visit by Botanophila, which serves to ‘pollinate’ the fungus with spermatia of the opposite mating type; the flies in t...

Taxon-specific polymerase chain reaction (PCR) primers enable detection of arbuscular mycorrhizal fungi (AMF, Glomeromycota) in plant roots where the fungi lack discriminative morphological and biochemical characters. We designed and validated pairs of new PCR primers targeted to the flanking regions of the variable domain 1 of the nuclear ribosoma...

Epichloë festucae (Ascomycota) infects the grass Festuca rubra. Infected plants may be more resistant to herbivores and obtain other benefits. The 5109bp dsRNA genome of a virus which infects E. festucae was sequenced, and its incidence in natural populations and transmission were studied. The viral genome has characteristics of the family Totiviri...

Epichloë typhina comprises interfertile strains associated with several grass species in tribes Poeae, Aveneae and Brachypodieae. Molecular phylogenetics indicate that E. typhina is paraphyletic to E. sylvatica and E. clarkii. Although interfertility barriers are evident between E. typhina and E. sylvatica, E. clarkii is interfertile with E. typhin...

Epichloë typhina comprises interfertile strains associated with several grass species in tribes Poeae, Aveneae and Brachypodieae. Molecular phylogenetics indicate that E. typhina is paraphyletic to E. sylvatica and E. clarkii. Although interfertility barriers are evident between E. typhina and E. sylvatica, E. clarkii is interfertile with E. typhi...

Epichloë species usually depend on flies of genus Botanophila which transfer gametes for sexual reproduction. Sequence analysis of COII detected six distinct Botanophila taxa that were associated with Epichloë in Europe and North America. Three were restricted to samples from Europe, two to samples from North America, and one was present on both...

Some isolates of Epichloë festucae are asymptomatically infected by Epichloë festucae virus 1 (EfV1), a member of the family Totiviridae. This virus has a genome composed by a 5109 bp molecule of double stranded RNA (dsRNA). In addition, a 3 kbp dsRNA molecule which could be the genome of another virus (EfV2) was frequently found in isolates of t...

Fungi produce a plethora of secondary metabolites yet their biological significance is often little understood. Some compounds show well-known antibiotic properties, others may serve as volatile signals for the attraction of insects that act as vectors of spores or gametes. Our investigations in an outcrossing, self-incompatible fungus show that a...

Altered environmental conditions may change populations of arbuscular mycorrhizal fungi and thereby affect mycorrhizal functioning. We investigated whether 8 yr of free-air CO2 enrichment has selected fungi that differently influence the nutrition and growth of host plants. In a controlled pot experiment, two sets of seven randomly picked single sp...

Epichloë endophytes are fungal symbionts of grasses that span a continuum including asexual mutualists that are vertically transmitted, obligately sexual pathogens that are horizontally transmitted, and mixed-strategy symbionts with both mutualistic and pathogenic capabilities. Here we show that processes of genome evolution differ markedly for the...

An analysis of population structure and genetic differentiation was conducted in three populations of the outbreeding perennial Ranunculus alpestris L. The populations were located along environmental gradients caused by gradual melting of snow (Pizol mountains, Switzerland). In each population, plants were collected along two transects that were p...

Rising atmospheric carbon dioxide partial pressure (pCO2) and nitrogen (N) deposition are important components of global environmental change. In the Swiss free air carbon dioxide enrichment (FACE) experiment, the effect of altered atmospheric pCO2 (35 vs. 60 Pa) and the influence of two different N-fertilization regimes (14 vs. 56 g N m−2 a−1) on...

Grasses (family Poaceae) and fungi of the family Clavicipitaceae have a long history of symbiosis ranging in a continuum from mutualisms to antagonisms. This continuum is particularly evident among symbioses involving the fungal genus Epichloe (asexual forms = Neotyphodium spp.). In the more mutualistic symbiota, the epichloe endophytes are vertica...

Epichloë species are self incompatible (heterothallic) fungi that must be fertilized by spermatia from individuals of opposite mating type for successful sexual reproduction to occur. Female flies of the genus Botanophila act as vectors of the fungi by ingesting and defecating spermatia (gametes) onto fungal stromata (fruiting bodies) after oviposi...

Host shifts of plant-feeding insects and parasites promote adaptational changes that may result in the formation of host races, an assumed intermediate stage in sympatric speciation. Here, we report on genetically differentiated and host-adapted races of the fungal endophyte Epichloë bromicola, which presumably emerged after a shift from the grass...

Elevated atmospheric pCO2 increases the C‐availability for plants and thus leads to a comparable increase in plant biomass production and nutrient demand. Arbuscular mycorrhizal fungi (AMF) are considered to play an important role in the nutrient uptake of plants as well as to be a significant C‐sink. Therefore, an increased colonization of plant r...

Grass endophytes (Clavicipitaceae, Ascomycota) are generally considered to be mutualists which increase the host's fitness. Infected plants are often more persistent and competitive than uninfected plants, influencing population dynamics and plant community diversity. However, most of this empirical evidence is based on studies focusing on agronomi...

Endophytes of the genus Epichloë (Clavicipitaceae, Ascomycota) are systemic symbionts of cool-season grasses. Their interactions with grass hosts may vary between mutualistic and pathogenic depending on the mode of endophyte reproduction. Sexual strains prevent flowering and seed set (choke disease) of the host and can be horizontally transmitted b...

Classification of endophytes inhabiting Lolium pratense (= Festuca pratensis) based on morphological and molecular phylogenetic characteristics is reported. From an extensive survey of L. pratense collected throughout Europe, we concluded that the overwhelmingly predominant endophyte was Neotyphodium x uncinatum. We constructed phylogenies based on...

Endophytic fungi of the genus Epichlo and their asexual Neotyphodium forms are thought to interact mutualistically with their host grasses, providing protection for the host against herbivores and pathogens mediated by fungal alkaloids. Most previous research has concentrated on agronomically important grasses, such as tall fescue, and its interact...

The fungal endophyte Epichloë sylvatica (Clavicipitaceae, Ascomycota) may obligatorily infect the woodland grass Brachypodium sylvaticum, on which it can display two alternative modes of reproduction. During the sexual cycle, external stromata suppress host flowering and production of seed (choke disease), whereas in the asexual cycle the fungus re...

Epichloe species are fungal symbionts (endophytes) of grasses, many of which are benign or mutualistic and have a balance of horizontal (contagious) and vertical (seed-borne) transmission, whereas others mainly transmit horizontally and are more antagonistic. Over the past eight years several Epichloe species have been described based largely on th...

Fungi in the genus Epichloë (Clavicipitaceae, Ascomycota) are endophytic and often mutualistic symbionts of many grasses in temperate areas. Species with a sexual cycle suppress host flowering and seed formation, whereas asexual fungi remain asymptomatic and transmit vertically by seed. Thus, the mode of reproduction may determine whether the symbi...

The three alkaloid groups—lolines, ergopeptides, and peramine— are typically associated with endophyte infection of grasses, with the main function to protect hosts against herbivores. We determined levels of N-formylloline, N-acetylloline, ergovaline, and peramine in 18 European grasses naturally infected with seed-transmitted Neotyphodium endophy...

Phaeosphaeria vilasensis, a new ascomycete species, is described and illustrated. It was found on submerged dead stems of Juncus sp. from a north temperate lake in Wisconsin. The ascospores are 3-septate, smooth, hyaline, becoming light brown at maturity, and possess a gelatinous sheath that extends in water.

The genus Epichloe sensu stricto includes several mating populations (biological species) of endophytic fungal symbionts of cool season grasses. To date, six Eurasian and one North American morphospecies have been described, and these approximately correspond to six distinct mating populations. Here we describe three additional Epichloe species fou...

1. Epichloe sylvatica (Ascomycota, Clavicipitaceae) is a host-specific endophyte of the woodland grass Brachypodium sylvaticum with two alternative modes of reproduction. The predominant asexual strains are seed transmitted (vertical), whereas the sexual strains are capable of contagious transmission (horizontal), mediated by ascospores produced on...

The genus Epichloë sensu stricto includes several mating populations (biological species) of endophytic fungal symbionts of cool season grasses. To date, six Eurasian and one North American morphospecies have been described, and these approximately correspond to six distinct mating populations. Here we describe three additional Epichloë species fou...

Epichloe species are endophytic symbionts of grasses which may differ in the relative importance of their sexual or asexual life cycles. Sexual reproduction of the fungus by stroma-formation prevents host flowering (choke) and thus is highly antagonistic, whereas asexual reproduction through clonal propagation in host seeds does not affect host fit...

Infection with the endophyte Neotyphodium uncinatum (Gams, Petrini and Schmidt) Glenn, Bacon, Price and Hanlin may influence drought resistance and competitive ability of meadow rescue (Festuca pratensis Huds.). We determined endophyte-related effects on some growth and physiological characteristics in one done of meadow fescue. In a growth chamber...

Growth and water status in meadow fescue (Festuca elatior L.; syn. F. pratensis Huds.) is affected by Neotyphodium and Phialophora endophytes. Meadow fescue is often infected with Neotyphodium uncinatum (Gams, Petrini and Schmidt) Glenn, Bacon, Price and Hanlin or cosymbiotically with this and a Phialophora-like endophyte. In a growth chamber exper...

species are ascomycetous fungi (family Clavicipitaceae) that are ecologically obligate symbionts of grasses. Because they can enhance host fitness by protection from biotic and abiotic stresses, but can also reduce host seed production, these symbionts span a continuum from antagonistic (highly pathogenic) to mutualistic. Their mutualistic or antag...

Epichloe species are ascomycetous fungi (family Clavicipitaceae) that are ecologically obligate symbionts of grasses. Because they can enhance host fitness by protection from biotic and abiotic stresses, but can aim reduce host seed production, these symbionts span a continuum from antagonistic (highly pathogenic) to mutualistic. Their mutualistic...

Neotyphodium is the newly proposed name for the asexual state of the clavicipitaceous genus Epichloë (Glenn et al. 1996). The members of this endophytic genus form systemic, long-term associations with numerous cool season grasses (Leuchtmann 1992, White 1987). In these associations, the two partners have developed an intimate relationships over ev...

The population biology of grass endophytes is uniquely different from that in other groups of fungi given their status (primarily) as mutualistic symbionts, their effects on organisms interacting with hosts, and their variable means of horizontal and/or vertical transmission. Because grass endophytes are biotrophic and form perennial associations w...

Life cycle and breeding system variation in Epichloe grass endophytes (choke disease) is tightly linked to the degree of stroma formation. It is not known whether this variation results from differences in host resistance, fungal virulence, or environmental conditions. We found genetic differentiation between 173 asymptomatic (NS) and 93 stromata-f...

On granite outcrops around Highlands, North Carolina four sympatric Danthonia grass species are infected by the fungus Atkinsonella hypoxylon (Clavicipitaceae). Danthonia epilis and D. sericea (rare hosts) are infected only in this small region, although they range more widely, while D. compressa and D, spicata (widespread hosts) are infected throu...

On granite outcrops around Highlands, North Carolina four sympatric Danthonia grass species are infected by the fungus Atkinsonella hypoxylon (Clavicipitaceae). Danthonia epilis and D. sericea (rare hosts) are infected only in this small region, although they range more widely, while D. compressa and D. spicata (widespread hosts) are infected throu...

Seventy-eight representatives of Trichoderma sect. Longibrachiatum, Hypocrea jecorina, and H. schweinitzii were compared using ten enzyme systems. The results essentially supported Bissett's morphologically based taxonomy of Trichoderma sect. Longibrachiatum, in that the species ?: longibrachiatum, ?: citrinoviride, ?: parceramosum, and TT: pseudok...

Seventy-eight representatives of Trichoderma sect. Longibrachiatum, Hypocrea jecorina, and H. schweinitzii were compared using ten enzyme systems. The results essentially supported Bissett's morphologically based taxonomy of Trichoderma sect. Longibrachiatum, in that the species T. longibrachiatum, T. citrinoviride, T. parceramosum, and T. pseudoko...

We analyzed the inheritance of mitochondrial DNA (mtDNA) species in matings of the grass symbiont Epichloë typhina. Eighty progeny were analyzed from a cross in which the maternal (stromal) parent possessed three linear plasmids, designated Callan-a (7.5 kb), Aubonne-a (2.1 kb) and Bergell (2.0 kb), and the paternal parent had one plasmid, Aubonne-...

Thirty strains of Xylaria cubensis isolated from leaves of the Brazilian rainforest palm Euterpe oleracea were compared by means of somatic incompatibility tests and gel electrophoretic analysis in order to gain further insights into their population dynamics. Five enzyme systems were used to assess genetic variability. Isozyme results showed that...

Thirty strains of Xylaria cubensis isolated from leaves of the Brazilian rainforest palm Euterpe oleracea were compared by means of somatic incompatibility tests and gel electrophoretic analysis in order to gain further insights into their population dynamics. Five enzyme systems were used to assess genetic variability. Isozyme results showed that...

Mating tests among stroma-forming and nonstroma-forming strains of Epichloë from several fine fescue species, including Festuca rubra subsp. rubra and F. rubra subsp. commutata, indicated a distinct mating population of Epichloë from the Festuca hosts. Reciprocal matings of these strains with E. typhina from Dactylis glomerata, Lolium perenne and A...

Mating tests among stroma-forming and nonstroma-forming strains of Epichloë from several fine fescue species, including Festuca rubra subsp. rubra and F. rubra subsp. commutata, indicated a distinct mating population of Epichloë from the Festuca hosts. Reciprocal matings of these strains with E. typhina from Dactylis glomerata, Lolium perenne and A...

Seed-borne fungal symbionts (endophytes) provide many cool-season grass species with biological protection from biotic and abiotic stresses. The endophytes are asexual, whereas closely related sexual species of genus Epichloë (Clavicipitales) cause grass choke disease. Perennial ryegrass (Lolium perenne) is a host of two endophyte taxa, LpTG-1 (L....

The relationships of 159 isolates of Acremonium endophytes from twelve Festuca host species, representing five subgenera, were investigated using starch gel electrophoresis of 11 enzymes. Cluster analysis of isozyme genotypes identified six distinct groupings with genetic identities (I) of 0·5 or less among groupings. Three groupings were previousl...

Isozyme analysis, morphological characters, sensitivity to benomyl in vitro, and the production of alkaloids in the fungal-host-grass associations were used to examine the relationships between Acremonium endophytes of Festuca arundinacea, F. pratensis and Lolium perenne. Isozyme analysis identified six taxonomic groupings, with each grouping compr...

Clavicipitaceous endophytes (Ascomycetes) are distributed worldwide in many grasses and sedges forming a perennial and often mutualistic association with their hosts. Most endophytes appear to produce alkaloid toxins in infected plants. The high frequency of infection in many grasses and in certain grassland communities may indicate a selective adv...

The host ranges of Epichloe typhina isolates from four host grasses were investigated by reciprocal seedling inoculations. Isolates from Elymus villosus, E. virginicus, and Hystrix patula could infect seedlings of each of those hosts plus Brachyelytrum erectum seedlings. Isolates from B. erectum could infect only seedlings from its original host sp...

The host ranges of Epichloë typhina isolates from four host grasses were investigated by reciprocal seedling inoculations. Isolates from Elymus villosus, E. virginicus, and Hystrix patula could infect seedlings of each of those hosts plus Brachyelytrum erectum seedlings. Isolates from B. erectum could infect only seedlings from its original host sp...

Isozyme variation of 70 endophytic Phyllosticta isolates representing four species from coniferous hosts and two species from angiospermous hosts was examined using starch gel electrophoresis of ten enzymes. All enzymes were polymorphic among species and each electromorph was restricted to a single host. Strains of Phyllosticta pseudotsugae were mo...

Allozyme variation was studied in all nine diploidErigeron species known from the Alps:E. alpinus, E. neglectus, E. polymorphus, E. candidus, E. uniflorus, E. atticus, E. gaudinii, E. acer, andE. angulosus. A total of 248 individuals from 24 natural populations was investigated using starch gel electrophoresis. Seven enzymes and 13 loci were assess...

At least two species of Amazonian sedges (piripiri, i.e., Cyperus articulatus and C. prolixus, Cyperaceae) are widely utilized for various medicinal purposes, including birth control and induction of labor, and in hallucinogenic preparations. Examination of herbarium specimens collected from throughout South America and of living specimens collecte...

Isozyme variation of 219 isolates of Acremonium or Epichloe fungal endophytes from 17 host grass species was examined using starch gel electrophoresis. Ten enzyme systems selected for use out of 17 examined were variable, with three to nine distinct electromorphs per enzyme. Most isolates produced a single band per enzyme, consistent with a haploid...

An EtOH extract of Cenchrus echinatus (sandbur grass) infected with Balansia obtecta, a fungal endophyte of the Clavicipitaceae, has yielded ergobalansine [1], a new ergot-type alkaloid. Ergobalansine is a peptide derivative of lysergic acid, but differs from other known ergopeptine alkaloids in that the characteristic proline residue has been repl...

Isozyme variation of 291 isolates of Atkinsonella hypoxylon (Clavicipitaceae, tribe Balansieae) from 24 populations of its four known host grasses (Danthonia compressa, Danthonia sericea, Danthonia spicata, and Stipa leucotricha) was examined using starch gel electrophoresis. In total, there were 20 distinct multilocus genotypes. Eleven out of 13 e...

Collections of grasses were made in spring in the vicinity of Indiana University in S-central Indiana. At least 16 species of woodland grasses were to be infected at least occasionally by clavicipitaceous endophytes, including 5 unreported host species. Agrostis hiemalis and A. perennans were infected very frequently (>75% of the individuals sample...

Comparative morphological and cultural studies in strains of Atkinsonella (Clavicipitaceae, tribe Balansieae) from all known host grasses (Danthonia compressa, D. spicata, D. sericea and Stipa leucotricha) revealed a number of characteristics distinguishing between strains from the allopatric host genera Danthonia and Stipa. Differences were found...

Comparative morphological and cultural studies in strains of Atkinsonella (Clavicipitaceae, tribe Balansieae) from all known host grasses (Danthonia compressa, D. spicata, D. sericea and Stipa leucotricha) revealed a number of characteristics distinguishing between strains from the allopatric host genera Danthonia and Stipa. Differences were found...

Variation in compatibility has been documented within and among several natural plant populations infected by fungal pathogens. In this study, seeds and isolates of the fungus Atkinsonella hypoxylon (Ascomycetes, Clavicipitaceae) were collected from three populations of the grass Danthonia spicata, two populations of D. compressa, and four populati...

Artificial infection of two grasses and one sedge with Atkinsonella hypoxylon and Balansia cyperi, respectively, is described. Prior inoculations of hosts with these and related fungi in the tribe Balansiae (Clavicipitaceae) have largely been unsuccessful. Seedlings grown in aseptic culture were infected by inserting mycelium and conidia with a nee...

Artificial infection of two grasses and one sedge with Atkinsonella hypoxylon and Balansia cyperi, respectively, is described. Prior inoculations of hosts with these and related fungi in the tribe Balansiae (Clavicipitaceae) have largely been unsuccessful. Seedlings grown in aseptic culture were infected by inserting mycelium and conidia with a nee...

Four species in the tribe Balansiae (Clavicipitaceae) infecting grasses and sedges were studied to determine their growth habit as endophytes or epiphytes. The genus Myriogenospora previously has been reported to be epiphytic but other members of the tribe have been presumed to grow endophytically in their hosts. Cultural and histological studies i...

Four species in the tribe Balansiae (Clavicipitaceae) infecting grasses and sedges were studied to determine their growth habit as endophytes or epiphytes. The genus Myriogenospora previously has been reported to be epiphytic but other members of the tribe have been presumed to grow endophytically in their hosts. Cultural and histological studies i...

Sixteen arctic-alpine species of Phaeosphaeriaare presented in a key with short descriptions and notes on host plants, distribution, and conidial states. Illustrations of all the species are also included. The geographical distribution of the arctic-alpine species forms three groups: species restricted to the Alps, species restricted to the Arctic,...

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