Molecular and morphological analyses confirm Rhizopogon verii as a widely distributed ectomycorrhizal false truffle in Europe, and its presence in South America.

Marcelo A Sulzbacher,Miguel Á García,Zaida I Antoniolli,Andressa Silveira,Bianca D Silva,Babette Münzenberger,María P Martín,Tine Grebenc,Paulo Marinho,Iuri G Baseia,M Teresa Telleria

doi:10.1007/s00572-015-0678-8

Abstract

The genus Rhizopogon includes species with hypogeous or subepigeus habit, forming ectomycorrhizae with naturally occurring or planted pines (Pinaceae). Species of the genus Rhizopogon can be distinguished easily from the other hypogeous basidiomycetes by their lacunose gleba without columella and their smooth elliptical spores; however, the limit between species is not always easy to establish. Rhizopogon luteolus, the type species of the genus, has been considered one of the species that are more abundant in Europe, as well as it has been cited in pine plantation of North and South America, different parts of Africa, Australia, and New Zealand. However, in this study, based on molecular analyses of the ITS nuclear ribosomal DNA (nrDNA) sequences (19 new sequences; 37 sequences from GenBank/UNITE, including those from type specimens), we prove that many GenBank sequences under R. luteolus were misidentified and correspond to Rhizopogon verii, a species described from Tunisia. Also, we confirm that basidiomes and ectomycorrhizae recently collected in Germany under Pinus sylvestris, as well as specimens from South of Brazil under Pinus taeda belong to R. verii. Thanks to the numerous ectomycorrhizal tips collected in Germany, a complete description of R. verii/P. sylvestris ectomycorrhiza is provided. Moreover, since in this paper the presence of R. verii in South America is here reported for the first time, a short description of basidiomes collected in Brazil, compared with collections located in different European herbaria, is included.

Highlights

The species of the genus Rhizopogon Fr. belong to the order Boletales and suborder Suillineae in the Agaricomycetidae (Binder and Hibbett 2006)
In Germany, fresh basidiomes and soil cores to collect ectomycorrhizal tips were taken from the abandoned coal mine area along the side road toward Schlabendorfer See near the village Crinitz; the area is represented by a ca. 30-year-old P. sylvestris plantation established on silicate sandy neosol with shallow organic layer and poor understory vegetation
Rhizopogon verii was originally described from Tunisia (Pacioni 1984a), under P. pinaster

Summary

Introduction

The species of the genus Rhizopogon Fr. belong to the order Boletales and suborder Suillineae in the Agaricomycetidae (Binder and Hibbett 2006). The genus is represented with over 100 species distributed worldwide (Smith and Zeller 1966; Martín 1996; Martín and García 2009). Rhizopogon species are easy to cultivate in pure culture (Molina and Trappe 1994; Brundrett et al 1996); some were frequently applied to study physiology, morphology, or ecology of its ectomycorrhizae in the agroforestry systems (Smith and Zeller 1966; Hung and Trappe 1983; Chu-Chou and Grace 1984; Miller 1986; Molina et al 1997; Beiler et al 2010). In posterior systematic studies undertaken in several part of the world, authors described new species in Mexico (Trappe and Guzmán 1971, Cázares et al 1992), Tunisia (Pacioni 1984a), China (Liu 1985), Japan (Mujic et al 2014), and different countries of Europe (Pacioni 1984b, Martín 1996, Martín and Calonge 2001); as well as new records, such as those of Mexico and Caribean countries (Hosford and Trappe 1980), Italy (Montecchi and Sarasini 2000), Japan (Hosford and Trappe 1988) and Spain (Martín and Calonge 2006), showing that the knowledge of the genus is not yet complete

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