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8/2/2019 Agaricus subrufesvens
Mycologia, 97(1), 2005, pp. 1224. 2005 by The Mycological Society of America, Lawrence, KS 66044-8897
Agaricus subrufescens, a cultivated edible and medicinal mushroom,
and its synonyms
Richard W. Kerrigan1
Sylvan Research, 198 Nolte Drive, Kittanning,Pennsylvania 16201
Abstract: Agaricus subrufescens Peck was cultivatedfirst in the late 1800s in eastern North America. Thetype consists partly of cultivated material and partlyof field-collected specimens. Once a popular marketmushroom, the species faded from commerce in theearly 20th century. More recently, a mushroom spe-cies growing wild in Brazil has been introduced intocultivation in Brazil, Japan and elsewhere. This Bra-zilian mushroom has been referred to by variousnames, most commonly as A. blazei Murrill (sensuHeinemann) and most recently as A. brasiliensisWas-ser et al. The author first cultivated A. subrufescensin1981 and has grown and studied Brazilian isolatessince 1992. The species has an amphithallic patternof reproduction. Based on DNA sequence analysis ofthe rDNA ITS region and on mating studies and ge-netic analysis of hybrid progeny, there is a strong casefor conspecificity of the Brazilian mushrooms with A.subrufescens. Based on a study of the type and other
data, the recent lectotypification of A. subrufescensisaccepted. Data are presented on mushrooms of di- verse geographical origins, including A. rufotegulisNauta from western Europe, another apparent con-specific. A possible role for interpopulational hybrid-ization in current populations of A. subrufescens isproposed. The agronomic history of the species isreviewed.
Key words: ABM, Cogumelo do Sol, Himematsu-take, interpopulational hybridization, phylogeogra-phy, Royal Sun Agaricus
Agaricus subrufescensPeck was first described in 1893by C.H. Peck, the New York state botanist, from twocollections. The first was of two mushrooms from acrop being cultivated at Dosoris (Glen Cove), New
York (sent 15 Oct 1892). Because these arrived inpoor condition, additional specimens found growing
Accepted for publication 8 Oct 2004.1 E-mail: firstname.lastname@example.org
in our [W. Falconers] leaf pile in old leaf moldthen were sent (apparently on 24 Oct 1892) (Peck1893; Falconer to Peck, in lit. [NYS]). The mush-room, called the almond mushroom or almond-flavored mushroom due to its fragrance and taste,
was widely cultivated, sold and eaten in the Atlanticstates of the United States from at least Massachusettsto Washington D.C., from the late 19th century intothe 20th (Falconer 1894a, b; Anon. 1904; Anonymous1909; Kauffman 1918). Spawn (inoculum culture forfarming) of A. subrufescens was even offered for sale
(Falconer 1894a, b; Anonymous 1909). As late as1918 Kauffman (1918) reported it to be in cultiva-tion. Commercial production of A. subrufescens sub-sequently declined as market trends changed; soonthe related button mushroom species Agaricus bi-sporus ( J.E. Lange) Imbach appears to have been theonly mushroom species being regularly cultivated inthe United States (see Duggar 1920, Charles 1931).
Agaricus subrufescensoften occurs in domesticatedor semidisturbed habitats, including leaf piles. It hasbeen recognized occasionally growing wild outsidenortheastern North America, for example in Califor-nia (Kerrigan 1982, 1983a, 1986; Kerrigan and Ross
1987a), Israel (R. Kenneth, personal communication198485), Taiwan (Tu and Lin 1981) and Hawaii,
where it grows under forest trees (Peterson et al2000). Brazilian examples in the past three decadeshave entered commerce and (not having been rec-ognized as A. subrufescens) raised questions, dis-cussed below, about nomenclature and identity. Inaddition, the recently described A. rufotegulis Nautafrom the Netherlands, the United Kingdom and Por-tugal (Nauta 1999, Hausknecht 2002) is also extreme-ly similar and considered here to be conspecific withA. subrufescens.
The history ofA. subrufescenswas reviewed by Ker-rigan (1983a); updated and extended informationfollows. A discussion of its properties as an easily cul-tivated mushroom was presented by Kerrigan (1983a,1984); notably, very similar outdoor methods are typ-ically employed in Brazil today. A culture (RWK 1185;
voucher at SFSU) of A. subrufescens was isolated byme from basidiomata growing in rich compost cov-ered with sandy soil for raspberry culture in Califor-nia in 1981. This culture was sold commercially tohobbyist mushroom growers (it recently has been cul-
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13KERRIGAN: AGARICUS SUBRUFESCENS
tivated at commercial scale in the United States and,based on sequence and other data, abroad (see be-low)). Reproductive micromorphology and geneticbehavior of this strain were investigated by Kerriganand Ross (1987a, b, unpublished).
Mushrooms originating in the Atlantic region of
Brazil and agreeing closely with Agaricus subrufescenshave begun in recent decades to be cultivated on abroad scale as medicinal mushrooms that are mar-keted primarily in Japan (Kerrigan 1983a, Wasser etal 2002). However, in this context the mushroom typ-ically is referred to (incorrectly) as A. blazei Mur-rill,A. blazei ss Heinem. (see Wasser et al )or, in some commercial literature and product pack-aging, A. sylvaticus.
The conventional account of the origin of Agari-cus blazei Murrill sensu Heinemann and its arrival in
Japan is related by Wasser et al (2002). It is consistentwith the account given to me by Mr Shusuke Minoura
in Hiroshima, Japan, in 1981. His account and myconclusion that the Brazilian Agaricusthen cultivatedin Japan was almost certainly A. subrufescens werepublished shortly thereafter with one of Minourasphotographs (Kerrigan 1983a). The conventionalhistory also agrees with a specific and plausible ac-count by Mr. B.-A. Eckart (personal communication)of Brazil and Germany, related to him by Mr ErnestoNoburo, which attributes the discovery of the Brazil-ian mushroom and its distribution to Japanese re-searchers to the late Mr Takatoshi Furumoto, an im-migrant from Japan to Piedade, Brazil. Details in thereport of Heinemann (1993) indicating that a cul-ture was isolated from a collection made at Sao Pau-lo, Piedade, Brazil, in Feb 1973, and cultivated in Ja-pan by Iwade, from which specimens (at BR) werepreserved by Hongo, are also concordant. See alsoSouza Dias et al (2004).
Controversy has existed regarding the correctname of the Brazilian species. A search of the World
Wide Web and a review of diverse commercial prod-uct literature indicated that association of the nameA. blazeiwith the Brazilian mushroom is attributed toP. Heinemann. Minoura used this name in 1981; thepublished taxonomic determination appears in
Heinemann (1993). The name A. sylvaticus Schaeff.sometimes is associated with the species, and this issaid to have resulted from a determination of Brazil-ian cultivated material made by a European mycolo-gist at the request of a Brazilian producer (R. Mazi-ero personal communication). Agaricus sylvaticuscustomarily is placed in section Sanguinolenti (F.H.Mller & Jul. Schaffer) Singer, while A. subrufescens(under any name and including Brazilian material)is certainly a member of section Arvenses Konrad &Maubl. (Kerrigan 1982, 1986).
Wasser et al (2002) rejected the name A. blazeiforthe Brazilian mushroom, correctly in this authorsopinion, and recognized the latter as a new species,A. brasiliensisWasser et al. Wasser et al also rejectedconspecificity between Brazilian mushrooms and A.subrufescens, based on features of spores and cheilo-
cystidia, although they wrote that the two speciesseemed to be each others closest relatives.
However, new data presented below indicate thatthe medicinal mushroom from Brazil and Japan isbiologically and phylogenetically the same species asA. subrufescensfrom North America. I will review fea-tures that have been emphasized in the literature onthe taxa involved. Because Pecks name A. subrufes-cens is older than A. brasiliensis, it has priority andtherefore is the correct name of the species. A. ru-
fotegulis Nauta equally belongs to A. subrufescens,based on overall morphological and sequence crite-ria. The rDNA ITS12 sequences from Hawaiianspecimens of A. subrufescens are the most divergentof those studied.
MATERIAL AND METHODS
All cultural and analytical methods were routine and havebeen described in earlier publications (Challen et al 2003,Kerrigan et al 1996). Samples evaluated are given (TABLEI). For microscopy, excised dried material was wetted in95% ethanol, then mounted and measured in 3% KOH;spore length excludes the apiculus. Cultures of commercialsamples of medicinal agaricus of Chinese and Japaneseorigin were obtained from spores aseptically washed from
lamellae of dried mushrooms, in the form of single sporeisolates (SSIs). The karyotic status (n versus n n) of eachSSI was determined from potato-dextrose yeast broth(PDYB) grown samples using allozyme markers includingpeptidase and esterase. Heteroallelic SSIs were assumed tobe heterokaryotic, while homoallelic SSIs were of uncertainstatus. Crosses were attempted between homoallelic SSIs onPDA, transferred to grain spawn medium, then compost(for cropping); successful hybrid cultures were isolated andcultured in PDYB for genetic analysis.
Some samples (A. rufotegulis, A. brasiliensis [Isotype], A.subrufescens DEH 1073, 513; KRP 070) were available onlyas herbarium specimens, from which DNA was isolated us-
ing the DNAEasy Plant Miniprep Kit (Quiagen). Living cul-tures were grown in PDYB, harvested, lyophilized and ex-tracted for DNA using the CTAB miniprep procedure (Zo-lan and Pukkila 1986).
Amplification of the ITS12 region of the rDNA, se