Incidence and compatibility of nonclavicipitaceous fungal endophytes inFestucaandLoliumgrass species

Abstract

The p-endophytes, previously identified as Gliocladium-like and Phialophora-\ike fungi, constitute a group of closely related, seed transmissible grass symbionts which have been found in several Festuca species and Lolium perenne, most often in cosymbiosis with mutualistic Epichloe-type (Acremonium) endo? phytes (e-endophytes). To help assess the ecological importance of p-endophytes, their incidence and the incidence of e-endophytes was determined in seed ac- cessions of Festuca and Lolium grass species in the U. S. Department of Agriculture Plant Introduction col? lection. Ten seeds of each accession were tested by tissue print immunoblot assay for the presence of e- or p-endophytes in separate seeds, or together in in? dividual seeds. A total of 370 accessions from 36 Fes? tuca species and five Lolium species were tested. The e-endophytes were present in 25 of the Festuca species and all of the Lolium species, while the p-endophytes appeared in five and one species, respectively. The p-endophytes were present in 18 Festuca accessions and six Lolium accessions, while the e-endophytes ap? peared in 121 and 43 accessions, respectively. The p- and e-endophytes were detected together in individual seeds in a total of five species and 13 accessions from both genera. Infectivity studies indicated that when p-endophytes from different species were introduced into their own and reciprocal hosts only the endo? phytes introduced into their own hosts produced sig? nificant levels of sustainable infections. Three conclu-