Taxonomic placement of Epichloëpoae sp.nov.and horizontal dissemination to seedlings via conidia

A new Epichloëspecies distributed in Africa,Europe,North America and South America on host genera Bromus,Festuca,Lolium and Poa is described.Stromata,characteristic of the genus,frequently occurred on the reproductive tillers of Poa secunda subsp.juncifolia,but neither perithecia nor mature asci were observed.Conidiogenous cells and conidial characteristics were in the range of Epichloëtyphina.Regions of the genes encodingβ-tubulin(tub2)and translation elongation factor 1-α(tef1)were amplified and sequenced.Phylogenetic analyses of these sequences grouped the Poa secunda subsp.juncifolia endophyte into one group within a non-hybrid Epichloëspecies complex.On the basis of morphology,host range and evolutionary history we propose that this endophyte represents a new species of Epichloë.The name Epichloëpoae is proposed for this endophyte.The infectivity of the conidia produced on plants was evaluated.In the first experiment,using conidia of Epichloëpoae from leaves and endophytefree seeds of Poa secunda subsp.juncifolia we show that when germinating seeds and developing seedlings of the plant were exposed to conidia,28–57%of seedlings became infected by the endophyte.The non-inoculated control plants showed no colonization by the endophyte.In the following spring after vernalization,colonized plants on flowering culms produced stromata with conidia.In the second experiment,using stromal conidia and the same procedure,19–42%of seedlings of Poa secunda subsp.juncifolia became colonized by the endophyte.Our results demonstrate that Epichloëpoae may spread to uninfected grass hosts by conidia frequently formed on the surfaces of plant leaves as well as by conidia formed on stromata.

Endophytic and pathogenic fungi of developing cranberry ovaries from flower to mature fruit:diversity and succession

Culturable fungal population diversity and succession was investigated in developing cranberry ovaries of fruit rot-resistant and rot-susceptible cranberry selections,from flower through mature fruit.Fungi were recovered in culture from 1185 of 1338 ovary tissues collected from June to September,yielding 2255 isolates that represented 42 morphotaxa.During the season,species richness varied from 2 to 17 and 2 to 18 in rot-resistant and rotsusceptible selections,respectively,increasing from wk1 to wk10 and then gradually declining to wk14.Shannon-Wiener diversity index varied from 0.27 to 2.32 in rotresistant and 0.18 to 2.38 in rot-susceptible,and Pielou’s evenness index varied from 0.11 to 0.63 and 0.06 to 0.64 in rot-resistant and rot-susceptible selections,respectively,confirming that diversity of fungi in developing ovaries was similar among rot-resistant and rot-susceptible selections,but varied among sampling time points.Principal component analysis grouped samples collected at the same sampling time point together regardless of rot susceptibility of the selections,and detected the predominant fungal species associated with each stage of development.Successional changes were observed in populations of endophytic,pathogenic and saprophytic fungi throughout the season as ovaries matured.