Isolation and molecular characterization of symbiotic fungus from Acromyrmex ambiguas and Acromyrmex heyeri ants of Rio Grande do Sul State, Brazil/Isolamento e caracterizacao molecular do fungo simbionte de formigas-cortadeiras do Rio Grande do Sul, Brasil

• Published in: Ciência rural p. 1256
• Main Authors: Pereira, Daniela Isabel Brayer, de Avila Botton, Sonia, de Azevedo, Maria Isabel, Monteiro, Danieli Urach, Weiblen, Carla, Machado, Vanessa Schopt, Donatti, Michele Guimaraes, Loeck, Alci Enimar
• Format: Journal Article
• Language: Spanish
• Published: Universidade Federal de Santa Maria 01-07-2015
• Subjects: Brasil
• ISSN: 0103-8478
• DOI: 10.1590/0103-8478cr20141064

Leaf-cutting ants of the genera Atta and Acromyrmex determine serious agricultural problems and live on symbiosis with Leucoagaricus gongylophorus. The aim of this study is to identify morphological and molecularly, as well as to verify the genotypic variability of the symbiotic fungus cultivated by A. heyeri and A. ambiguus from three different regions of the state of Rio Grande do Sul, Brazil. Fungus gardens were collected and fragments of mycelia were grown in selective medium. Total DNA was extracted and amplification of the ITS region was performed by PCR using universal primers. After DNA sequencing, the chromatograms were assembled and phylogenetic analyzes were performed by the Neighbor-Joining method. A total of six isolates of L. gongylophorus were obtained and their identities were confirmed by molecular analyses. Phylogenetic analysis of the ITS region showed a tree with two distinct groups regarding the fungus isolates from A. heiyeri and A. ambiguous. In this study, it was verified that A. heyeri and A. ambiguous, cultivate the same fungus. Additionally, the molecular marker used in this study showed variations in L. gongylophorus, evidencing two distinct branches in the phylogenetic tree, according to the ant species that cultivate L. gongylophorus. However, other studies involving the inclusion of a great number of isolates of L. gongylophorus, as well as the use of other molecular markers to validate the possible variations in the phylogenetic relationship of this symbiotic fungus are required. Key words: Basidiomycete, Leucoagaricus gongylophorus, internal transcribed spacer. Formigas-cortadeiras dos generos Atta e Acromyrmex causam elevados prejuizos a agricultura e sao dependentes obrigatorias da simbiose com Leucoagaricus gongylophorus. O objetivo deste estudo foi identificar morfologicamente e molecularmente, bem como verificar a variabilidade genotipica do fungo simbionte, cultivado por Acromyrmex heyeri e Acromyrmex ambiguus em tres regioes do RS, Brasil. Jardins de fungo foram coletados do interior de formigueiros e fragmentos de micelio foram cultivados em meio de cultura seletivo. O DNA total foi extraido e a amplificacao da regiao ITS foi realizada por PCR, utilizando primers universais. Apos sequenciamento, os cromatogramas foram montados e as analises filogeneticas foram realizadas pelo metodo de Neighbor-Joining. Dos jardins de fungo, obtiveram-se seis isolados de L. gongylophorus, confirmados por analise molecular. A analise filogenetica da regiao ITS mostrou uma arvore com dois grupos distintosem relacao aos isolados do fungo oriundos de ninhos de A. heyeri e A. ambiguus. Neste estudo, evidenciou-se que as especies de formigas A. heyeri e A. ambiguus cultivam o mesmo fungo. Entretanto, o marcador molecular estudado evidenciou variacoes de L. gongylophorus que permitiram formar duas ramificacoes diferentes na arvore filogenetica relacionada a especie de formiga que o cultiva. Todavia, para validar as possiveis variacoes nas relacoes filogeneticas deste fungo simbionte, e necessaria a inclusao de um maior numero de isolados de L. gongylophorus, bem como o emprego de outros marcadores moleculares. Palavras-chave: Basidiomicetos, Leucoagaricus gongylophorus, internal transcribed spacer.