XVI International Botanical Congess

Sexual Epichloe and related asexual Neotyphodium spp. are vertically transmitted fungal symbionts of grasses. Neotyphodium coenophialum and its host, Lolium arundinaceum, are both hybrids, the grass is L. arundinaceum var. glaucescens X L. pratense, and the 3 likely ancestors of N. coenophialum are N. uncinatum (symbiont of L. pratense), Epichloe festucae, and E. baconii. Sequence analysis of nuclear gene introns indicated genotypes similar to N. coenophialum that were symbiotic with 2 autotetraploid grasses, L. a. var. glaucescens and L. mazzettianum, and with several hybrid Lolium spp. This finding and the relationship between N. coenophialum and N. uncinatum indicate that the symbionts have long associated with grass genus Lolium, and that N. coenophialum is a clone whose origin predates the emergence of its modern host species.