title: Morphological and molecular characterization of three Agaricus species from tropical Asia (Pakistan, Thailand) reveals a new group in section Xanthodermatei.
abstract: The genus Agaricus is known for its medicinal and edible species but also includes toxic species that belong to section Xanthodermatei. Previous phylogenetic reconstruction for temperate species, based on sequence data of nuc rRNA gene (rDNA) internal transcribed spacers (ITS), has revealed two major groups in this section and a possible third lineage for A. pseudopratensis. Recent research in Agaricus has shown that classifications need improving with the addition of tropical taxa. In this study we add new tropical collections to section Xanthodermatei. We describe three species from collections made in Pakistan and Thailand and include them in a larger analysis using all available ITS data for section Xanthodermatei. Agaricus bisporiticus sp. nov. and A. fuscopunctatus sp. nov. are introduced based on molecular and morphological studies, whereas A. microvolvatulus is recorded for the first time in Asia. Specimens from Thailand however have a much larger pileus than the type specimens from Congo. In maximum likelihood (ML) and maximum parsimony (MP) phylogenetic analyses these three species cluster with A. pseudopratensis from the Mediterranean area and A. murinocephalus recently described from Thailand. In Agaricus section Xanthodermatei this new group is monophyletic and receives low bootstrap support whereas the two previously known groups receive strong support. Within the new group, the most closely related species share some traits, but we did not find any unifying morphological character; however the five species of the group share a unique short nucleotide sequence. Two putatively toxic species of section Xanthodermatei are now recognized in Pakistan and six in Thailand.
authors.affiliation: Institute of Excellence in Fungal Research and School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand.
authors.forename: Naritsada
authors.initials: N
authors.lastname: Thongklang
authors.affiliation: Department of Botany, University of the Punjab, Lahore, Pakistan.
authors.forename: Rizwana
authors.initials: R
authors.lastname: Nawaz
authors.affiliation: Department of Botany, University of the Punjab, Lahore, Pakistan.
authors.forename: Abdul N
authors.initials: AN
authors.lastname: Khalid
authors.affiliation: Institute of Excellence in Fungal Research, and School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand.
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.affiliation: Institute of Excellence in Fungal Research, and School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Hyde
authors.affiliation: The State Key Lab of Mycology, Institute of Microbiology, Chinese Academic of Science, Beijing 100101, China.
authors.forename: Ruilin
authors.initials: R
authors.lastname: Zhao
authors.affiliation: Avda. Padre Claret 7, 5° G, 09400 Aranda de Duero, Burgos, Spain.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Parra
authors.affiliation: Department of Botany, Government College University, Lahore, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Hanif
authors.affiliation: INRA, UR 1264, Mycologie et Sécurité des Aliments, CS 20032, 33882 Villenave d'Ornon CEDEX, France.
authors.forename: Magalie
authors.initials: M
authors.lastname: Moinard
authors.affiliation: INRA, UR 1264, Mycologie et Sécurité des Aliments, CS 20032, 33882 Villenave d'Ornon CEDEX, France callac@bordeaux.inra.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Callac
mesh_terms: D000364:Agaricus / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification; D001483:Base Sequence; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D048690:Fruiting Bodies, Fungal; D008969:Molecular Sequence Data; D010154:Pakistan; D010641:Phenotype; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013172:Spores, Fungal; D013785:Thailand
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer
keywords: basidiomycota; morphology; new species; phylogeny; tropical biodiversity