Positive association between Neotyphodium endophytes and arbuscular mycorrhizal fungi: a widespread trait.

NOVAS, M.V.; IANNONE, L.J.; VIGANLE, M.V.; SCERVINO, J.M.

Lexington, Kentucky

Simposio; The International Symposium on Fungal Endophytes of Grasses; 2010

The effect of epichloë endophytes on the symbiosis between Arbuscular mycorrhizal fungi (AMF) and wild native grasses was studied in Neotyphodium-infected (E+) and uninfected (E-) plants in natural populations of Bromus setifolius and Poa bonariensis, and in a field experiment with B. auleticus. In vitro assays were carried out in order to study the effect of four strains of Neotyphodium, isolated from B. setifolius, on pre-infective stages of two species of AMF: Gigaspora margarita and G. rosea. The AMF colonization was significantly higher in E+ populations than in E- populations for all three hosts. No significant differences were detected between E+ and E- plants when they coexisted in the same population. In vitro assays revealed that exudates from endophyte strains significantly enhanced hyphal length and the number of hyphal branches in AMF. Our results suggest that the positive effect of Neotyphodium endophytes on AMF is a widespread phenomenon in native grasses.