MOLECULAR CHARACTERIZATION OF MYRIOGENOSPORA-ATRAMENTOSA AND ITS OCCURRENCE ON SOME NEW HOSTS

Myriogenospora atramentosa produces partial to complete sterility of h ost grasses. Geographical and host species distributions were assessed and updated. It is reported only from the New World and appears to be limited to the highly evolved grass tribes Andropogoneae and Paniceae . Included in these tribes are the previously unreported host species Panicum scoparium, Paspalum urvillei, Erianthus brevibarbis, E. contor tus, E. giganteus, and hybrids from crosses with Erianthus spp. Additi onally, M. atramentosa is reported for the first time growing on Paspa lum notatum (bahiagrass), and Panicum hemitomon in South Carolina, U.S .A. Sequence data (ITS regions 1 and 2 and 5.8S rDNA) from several iso lates indicated that there is a significant level of DNA sequence diff erentiation between isolates of M. atramentosa, which suggests that th ere are at least two distinct sequence groups, or cryptic species, wit hin the currently defined morphological species.