Evolutionary diversification of fungal endophytes of tall fescue grass by hybridization with Epichloë species

摘要: Abstract The mutualistic associations of tall fescue (Festuca arundinacea) with seed-borne fungal symbionts (endophytes) are important for fitness the grass host and its survival under biotic abiotic stress. The endophytes asexual relatives biological species (mating populations) genus Epichloe (Clavicipitaceae), sexual fungi that cause choke disease. Isozyme studies have suggested considerable genetic diversity among fescue. Phylogenetic relationships seven isolates from fescue, three meadow (a probable ancestor fescue), nine other were investigated by comparing sequences noncoding segments beta-tubulin (tub2) rRNA (rrn) genes. Whereas each isolate endophyte had only a single tub2 gene, most two or distinct copies. analysis indicated presence multiple copies in was consequence hybridization species. At least events account distribution These results suggest interspecific is major diversification endophytes.