No evidence of fungal endophytes in native and exotic Phragmites australis

Native and exotic haplotypes of Phragmites australis show differential susceptibility to herbivores, but the mechanisms behind these differences are not known. Endophytic fungi are common in the grass family and confer resistance against insects through the production of toxic chemicals. We used both a common endophyte-staining technique and interference contrast microscopy to analyze leaf sheaths of native and exotic P. australis haplotypes from several populations in the northeastern United States to determine if the various haplotypes were infected with endophytes. No endophytes were found in any of the native and exotic haplotypes using procedures that consistently detected endophytes in infected rye grass.