Evolution of Reproductive Morphology In Leaf Endophytes
The endophytic lifestyle has played an important role in the evolution of the morphology of reproductive structures... more The endophytic lifestyle has played an important role in the evolution of the morphology of reproductive structures (body) in one of the most problematic groups in fungal classification, the Leotiomycetes (Ascomycota). Mapping fungal morphologies to two groups in the Leiotiomycetes, the Rhytismatales and Hemiphacidiaceae reveals significant divergence in body size, shape and complexity. Mapping ecological roles to these taxa reveals that the groups include endophytic fungi living on leaves and saprobic fungi living on duff or dead wood. Finally, mapping of the morphologies to ecological roles reveals that leaf endophytes produce small, highly reduced fruiting bodies covered with fungal tissue or dead host tissue, while saprobic species produce large and intricate fruiting bodies. Intriguingly, resemblance between asexual conidiomata and sexual ascomata in some leotiomycetes implicates some common developmental pathways for sexual and asexual development in these fungi.
Competition between foliar Neotyphodium lolii endophytes and mycorrhizal Glomus spp. fungi in Lolium perenne depends on resource supply and host carbohydrate content
Coauthored with: Qianhe Liu, Anthony J. Parsons, Hong Xue, Karl Fraser, Geraldine D. Ryan, and Susanne Rasmussen
1. Cool-season grasses can be simultaneously infected by foliar fungal endophytes and colonised by mycorrhizal fungi,... more
1. Cool-season grasses can be simultaneously infected by foliar fungal endophytes and colonised by mycorrhizal fungi, the integrated functions of which are strong predictors of plant fitness within grassland ecosystems. Evidence has been presented previously that infection of grass species with foliar endophytes can negatively affect mycorrhizal colonisation. Here, we tested the hypothesis that mycorrhizal colonisation in turn adversely affects Neotyphodium endophyte concentrations and that the competitive interaction between the two endosymbionts is affected by resource supply.
2. Specifically, we report how competition between Glomus (G. mosseae– GM, G. intraradices– GI) mycorrhizal fungi and N. lolii (common strain (CS) and AR1) foliar endophytic strains is affected by P supply and water-soluble carbohydrate (WSC) content in two Lolium perenne (perennial ryegrass) cultivars: a high sugar grass, AberDart, and a conventional (control) grass, Fennema.
3. The presence of Glomus mycorrhizae reduced the concentrations of endophytes and alkaloids in leaf blades and pseudostems. The reduction depended on P supply, ryegrass cultivar (notably WSC content) and endophyte strain. Conversely, foliar endophyte infection reduced mycorrhizal colonisation rates and concentrations in the roots of the control cultivar Fennema, although not in the high sugar cultivar, AberDart.
4. Neither GM nor N. lolii infection had an effect per se on the yield of root or blade compared with mycorrhiza-free (M-) and endophyte-free (E-) plants, respectively; though, yield of roots and blades was reduced by GI infection and at low P.
5. Competitive interactions between ecologically widespread foliar endophytes (valuable for plant protection) and mycorrhizal endosymbionts (valuable for P acquisition) as seen in this study are of critical importance especially in areas of high pest prevalence and low P availability. Our work stresses the need for elucidating the physiological/metabolic basis for such interactions between endosymbionts to understand how these processes contribute to plant performance and fitness in grassland ecosystems.
The phylogenetic position of Obolarina dryophila (Xylariales).
Mycol Prog 9:501-507 (2010)
Inconspicuous inner-bark parasite Obolarina dryophila is reported from wood of Quercus petraea and as an endophyte of... more Inconspicuous inner-bark parasite Obolarina dryophila is reported from wood of Quercus petraea and as an endophyte of Salix alba. In addition, viable ascospores of O. dryophila have been found in the gut of oak bark weevil Gasterocercus depressirostris, suggesting a possible dissemination mechanism for the fungus. A phylogenetic analysis based on three genes (nrDNA, actin, β-tubulin) placed Obolarina inside the genus Biscogniauxia as a close relative to oak pathogens B. atropunctata and B. mediterranea.
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