Evidence for amphithallism and broad geographical hybridization potential among Agaricus subrufescens isolates from Brazil, France, and Thailand Naritsada THONGKLANG a , Eric HOANG b , Alma E. RODRIGUEZ ESTRADA c , Phongeun SYSOUPHANTHONG a , Magalie MOINARD b , Kevin D. HYDE a , Richard W. KERRIGAN d , Marie FOULONGNE-ORIOL b , Philippe CALLAC b, * a Institute of Excellence in Fungal Research, and School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand b INRA, UR1264 MycSA, Mycologie et s ecurit e des aliments, CS 20032, 33883 Villenave d’Ornon Cedex, France c Aurora University, Biology Department, 347 S. Gladstone Ave., Aurora, IL 60506-4892, USA d Sylvan Biosciences, 198 Nolte Drive, Kittanning, PA 16201, USA article info Article history: Received 28 May 2014 Received in revised form 9 October 2014 Accepted 17 October 2014 Available online 27 October 2014 Keywords: Interfertility Life cycle Meiosporogenesis Postmeiotic mitosis Pseudohomothallism abstract Agaricus subrufescens is a cultivated edible and medicinal mushroom. Its known geograph- ical distribution encompasses the Americas, Europe, Oceania, and Asia. The objective of this study was to assess mating compatibility and interfertility of strains originating from Brazil, France, and Thailand. Progeny of each strain were analyed with codominant molecular markers. Multilocus genotype tests revealed that the three strains were amphi- thallic with percentages of heterokaryotic single spore progenies of 75 % for the Thai strain and around 40 % for the Brazilian and French strains. In mating tests A. subrufescens had a multiallelic unifactorial system of sexual incompatibility. The three parent strains were interfertile based on experimental pairings of single-spore isolates, the recovery of hybrid heterokaryons from compatible matings, and the ability of hybrids to produce mushrooms and fertile spores. This biological approach supports the inclusion of the Euro- pean strains within the species and the extension of the geographical distribution range to Asia. Our data should help to develop breeding strategies and to better manage and exploit the diversity existing in A. subrufescens. ª 2014 The British Mycological Society. Published by Elsevier Ltd. All rights reserved. Introduction In the family Agaricaceae (Basidiomycota), Agaricus subrufescens Peck belongs to Agaricus section Arvenses (Zhao et al. 2011) and has an almond odour which characterizes and distinguishes this section from section Bivelares, to which the button mush- room Agaricus bisporus belongs (Kerrigan et al. 2008). Both spe- cies are saprotrophic and can be cultivated on similar types of * Corresponding author. Tel.: þ33 557 12 24 90; fax: þ33 557 12 25 00. E-mail address: callac@bordeaux.inra.fr (P. Callac). journal homepage: www.elsevier.com/locate/funbio fungal biology 118 (2014) 1013 e1023 http://dx.doi.org/10.1016/j.funbio.2014.10.004 1878-6146/ª 2014 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.