Evidence supporting the occurrence of a new species of endophyte in some South American grasses

Endophytes of several South American grasses were examined. The taxonomic status of endophytes in Festuca argentina, F. hieronymi, Poa huecu, and an unidentified species of Poa is evaluated. On the basis of morphological features, and rDNA and protease gene sequence data, it is proposed that this endophyte is different from several other endophytes examined from North American, South American, and European species of Festuca and Pen. These endophytes, believed responsible for causing the 'tembladera' or 'huecu' toxicosis in animals, have also been reported to produce unique toxins. Isozyme analysis supports the distinctness of these endophytes but also demonstrates variability in populations with respect to gene polymorphisms. Taking all the data into consideration, we propose to establish a new endophyte species Neotyphodium tembladerae which includes endophytes found in multiple grass species. We suggest the use of a phylogenetic species concept to define species of Neotyphodium.