ORIGINAL PAPER Endophytic and mycorrhizal fungi associated with roots of endangered native orchids from the Atlantic Forest, Brazil Sabrina Feliciano Oliveira & Melissa Faust Bocayuva & Tomás Gomes Reis Veloso & Denise Mara Soares Bazzolli & Cynthia Canedo da Silva & Olinto Liparini Pereira & Maria Catarina Megumi Kasuya Received: 13 March 2013 / Accepted: 10 June 2013 # Springer-Verlag Berlin Heidelberg 2013 Abstract The composition and diversity of fungal commu- nities associated with three endangered orchid species, Hadrolaelia jongheana, Hoffmannseggella caulescens, and Hoffmannseggella cinnabarina, found in different vegeta- tion formations of the Atlantic Forest were determined by constructing clone libraries and by applying diversity and richness indices. Our results demonstrated the presence of Basidiomycetes. Sebacinales (81.61 %) and Cantharellales (12.10 %) were the dominant orders and are potential candi- dates for orchid mycorrhizal fungi. The Ascomycetes iden- tified included the Helotiales (29.31 %), Capnodiales (18.10 %), and Sordariales (10.34 %), among others. These orders may represent potentially endophytic fungi. A Shannon–Wiener diversity index (H′) analysis showed a relatively high fungal community diversity associated with these tropical orchids. This diversity may offer greater flex- ibility in terms of the adaptation of the plants to changing environmental conditions and the potential facilitation of reintroduction programs. The Simpson diversity index values showed that all of the libraries included dominant species, and a LIBSHUFF analysis showed that the fungal communities were structurally different from each other, suggesting an influence of local factors on this diversity. This study offers important information for the development of conservation strategies for threatened and endemic species of Brazilian flora in an important and threatened hotspot. Keywords Fungal diversity . Hadrolaelia jongheana . Hoffmannseggella caulescens . Hoffmannseggella cinnabarina . Hotspot . ITS clone library Introduction It is known that the development of Orchidaceae in nature depends particularly on mycorrhizal fungi because the colo- nization of the roots by compatible fungi supplies young plants with carbon and inorganic nutrients (Rasmussen 1995). The greatest orchid diversity is found in the Neotropics (Pridgeon 1995). The Atlantic Forest biome is a complex eco- system of extreme importance because it constitutes a significant portion of the biodiversity found in Brazil and in the world (Stehmann et al. 2009). It is recognized as one of 34 biodiversity hotspots worldwide (Mittermeier et al. 2004). Occurring in this hotspot are Hadrolaelia jongheana (Rchb. f.) Chiron, one of the rare Brazilian orchid species (Decker 1941), and the genus Hoffmannseggella, which comprises species that are strictly rupicolous (that grow on rocks) and are endemic to southeastern Brazil, such as Hoffmannseggella cinnabarina (Bateman ex Lindl.) HG Jones and Hoffmannseggella caulescens (Lindl.) HG Jones. Because 47 % of all Hoffmannseggella species are composed of different populations that, in many cases, are found near an expanding industrial complex area outside legal Electronic supplementary material The online version of this article (doi:10.1007/s00572-013-0512-0) contains supplementary material, which is available to authorized users. S. F. Oliveira : M. F. Bocayuva : T. G. R. Veloso : D. M. S. Bazzolli : M. C. M. Kasuya (*) Microbiology Department, Federal University of Viçosa, Peter Henry Rolfs Avenue, s/n, CEP 36570-000 Viçosa, Minas Gerais, Brazil e-mail: mkasuya@ufv.br C. C. da Silva Biology Department, Federal University of Viçosa, Peter Henry Rolfs Avenue, s/n, CEP 36570-000 Viçosa, Minas Gerais, Brazil O. L. Pereira Phytopathology Department, Federal University of Viçosa, Peter Henry Rolfs Avenue, s/n, CEP 36570-000 Viçosa, Minas Gerais, Brazil Mycorrhiza DOI 10.1007/s00572-013-0512-0