Biochemical consequences of endophytic fungi“grass mutualism

The grasses Lolium perenne and Festuca arundinacea generally exhibit superior levels of persistence and greater productivity if infected with the fungal endophytes Neotyphodium lolii and Neotyphodium coenophialum, respectively, when subject to some biotic and abiotic stresses. This superior level of persistence and greater productivity are considered to be due to production of a spectrum of bioactive secondary compounds. The major groups of secondary metabolites that mediate resistance in grasses against biotic and abiotic stresses include alkaloids, phenolic, and volatile compounds. The aims of this thesis were to determine the profile of the alkaloids, phenolics, and volatile oils in populations of L. perenne infected with different strains of N. lolii (strains AR1 (EAR1), AR37 (EAR37), wild type (EWT)) and in the Mediterranean (M) and Continental (C) germplasms of F. arundinacea infected with N. coenophialum strain AR542 (EAR542). In addition, the behaviour of H. arator “ an important pestiferous insect of pastures in eastern NSW“ towards L. perenne either endophyte“free (E“) or those infected with N. lolii strains EAR1, EAR37 or EWT and towards Mediterranean and Continental F. arundinacea both either E“ or infected with N. coenophialum strain EAR542 have been determined.