The presence and absence of an endophytic fungus in Lolium temulentum and L. perenne

Abstract

Summary The study of a series of pedigree populations of single plants of L. temulentum and L. perenne extending through six seasons has shown that both species can exist either with or without an endophytic fungus. This fungus, when it occurs, invades the leaves, stems and tiller buds, and in a perennial plant it is distributed by vegetative propagation. It does not appear to invade the roots and it is in my opinion distinct from the Phycomycete type which has been recorded in these and other grasses, and in plants not closely related. The Lolium endophyte invades the ovule, and that it is mechanically inherited from the female parent only has been shown by the reciprocal crossing of free and infected plants. While races free from infection may arise from infected individuals, the origin of the infected races themselves is still obscure. The problems of chief interest, namely, the identity of the organism and the biological aspects of its connection with the grasses, still await solution. That the relation is not an obligate one so far as the higher plant is concerned emerges from the experimental work discussed in this paper.