Effect of climate and phenological stage on fungal endophytes community in Sorghum bicolor leaves

Abstract

Endophytic fungi comprise a group of microorganisms of great diversity, which can be modulated by biotic and abiotic factors. The present study aims to understand how environmental factors, blooming and cultivars change the diversity of the endophytic fungal communities in sorghum leaves in two forest areas in Brazil. Our results showed that Sorghum bicolor has a rich and diverse community of endophytic fungi distributed in Ascomycota, Basidiomycota and Mucoromycota, with members of Dothideomycetes and Sordariomycetes as dominant groups. We found 581 endophytic fungi (filamentous and yeasts) identified in 55 species of 37 genera. A greater diversity and richness of endophytic fungi were found in sorghum leaves from the Atlantic Forest (diversity = H′ = 2.68 and richness = 46), differing significantly from the Caatinga forest (diversity = H′ = 2.51 and richness = 25). No difference in richness or diversity was observed between the two crops or between the phenological stages. We detected different species indicator for the two areas, nine taxa were associated with sorghum in the Atlantic Forest (Colletotrichum sp. 2, Epicoccum sorghinum, Curvularia sp., Colletotrichum sp. 1, Fusarium thapsinum, Nigrospora oryzae, Phyllosticta capitalensis, Fusarium oxysporum and Amesia nigricolor) and five taxa were indicators of sorghum in the Caatinga Forest (Meyerozyma sp., Talaromyces pinophilus, Metschnikowia sp., Rhodosporidiobolus sp. and Acremonium pinkertoniae). One species was an indicator of the cultivar IPA 2502 and no species were related to the cultivar IPA SF15. In relation to pre-blooming and post-blooming stages, two species were considered indicators for the former while six were considered for the latter. We observed that the number of filamentous fungi increases with the post-blooming stage and higher rainfall, while the diversity of endophytic yeasts was influenced by smaller rainfall and pre-blooming stage. Our data improves the understanding of factors that may influence the endophytic fungal community in ecologically and economically important grass species. The endophytic fungal diversity associated with sorghum is important to the mycodiversity estimation and may be useful in studies of biocontrol of pathogens and promotion of crops growth.