Fungal endophyte diversity from tropical forage grass Brachiaria

摘要

Background: Microbial endophytes can be beneficial to host plants, improving resistance against biotic and abiotic stress. While beneficial fungal endophytes have been well characterised in temperate grasses, knowledge about fungal endophytes of tropical grasses is limited. Aims: We investigated the diversity of fungal endophytes associated with Brachiaria, a tropical grass genus native to Africa to source candidate endophytes for developing as beneficial inoculants for cultivated Brachiaria. Methods: Fungi were isolated from asymptomatic tillers of nine Brachiaria species. Morphological and molecular techniques were used to investigate the taxonomic identities and phylogenetic relationships of the putative fungal endophytes. Results: One hundred and seventy-seven fungi were isolated, generating 38 operational taxonomic units (OTU) in total, which were predicted to represent 38 potential species. The most common isolates were related to Acremonium, Cladosporium, Emericellopsis, Plectosphaerella and Sarocladium. Multiple strains of Sarocladium terricola were detected and shown by molecular and morphological characterisation as identical to the first recorded seed-transmitted endophyte from Brachiaria, originally identified as Acremonium implicatum. Conclusion: A large and genetically diverse collection of putative endophytes from Brachiaria have been identified. Future work will elucidate whether any of these could be developed as beneficial endophyte inoculations able to offer bio-protective benefits for the health of Brachiaria.