A symptomless endophyte of ryegrass(Lolium perenne) that spores on its host — a light microscope study

Abstract

Abstract The incidence and intensity of infection by a Gliocladium-like, symptomless endophyte were monitored in a pasture of Lolium perenne L. by observing fungal hyphae in sections of pseudostems of ryegrass tillers in the vegetative phase of growth. Incidence and intensity were low during summer, increased to a maximum in winter, and then declined in spring. A second endophyte, Acremonium lolii Latch, Christensen and Samuels was also present in most plants, but its incidence and intensity became greatest as the Gliocladium-like endophyte declined. Hyphae of the Gliocladium-like endophyte occurred in intercellular spaces of the leaf sheath, and less profusely of the leaf blade, assuming swollen or contorted forms during the period of highest intensity of infection in winter. At this time, sporodochia of the Gliocladium-like endophyte protruded through the stomata of leaf blades whose tissues were beginning to degenerate. Simultaneously, conidia developed in air spaces in the mesophyll, and sporodochia o...