Revista Mexicana de Micología ISSN: 0187-3180 [email protected] Sociedad Mexicana de Micología México

Alvarado-Castillo, Gerardo; Mata, Gerardo; Sangabriel-Conde, Wendy Understanding the life cycle of morels (Morchella spp.) Revista Mexicana de Micología, vol. 40, diciembre, 2014, pp. 47-50 Sociedad Mexicana de Micología Xalapa, México

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How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Entendiendo el ciclo de vida de las morillas (Morchella spp.) Resumen. Se generó un ciclo de vida teórico de Morchella analizando los dos modelos existentes y complementándolos con información relacionada a su cultivo, observaciones experimentales y otras investigaciones. Se da especial atención a los diferentes estados celulares yalas condiciones ambientales para entender mejor su ciclo biológico. Palabras clave: escIerocios, ascocarpos, domesticación, plasticidad genética.

Abstract. Atheoreticallife cycle ofMorchella was generated, analyzing two existing models and complementing these with information relating to their cultivation, experimental observations and other research. Consideration was given to differentstages, cellular states and environmental conditions in orderto better understand ils biological cycle. Keywords: sclerotia, ascocarps, domestication, genetic plasticity.

Recibido 28 de mayo 2013; aceptado 20 de noviembre 2014. Received 28 May 2013; accepted 20 November 2014.

Edible musbrooms ofthe genus Morchella (Ascomycota) are secondary myceJium (by the crossing of vegetative important for their ecologicalrole andhigh commercialvalue myceJium), formation of sclerotia (structores resistant 10 at national and interoational level (Amir et al., 1993; adverse conditions), "germination" ofsclerotia, development Masaphy, 2005; Greene et al., 2010), for which reason of primordia and formation of fruiting bodies (ascocarps). numerous attempts have been made 10 cultivate them. The latter study is based on the previous model, but includes However, the lack of knowledge regarding their biological cellular stages of the phenological phases and some processes, as well as the factors tbattriggerthe differentiation ecological conditionsunderwhichthe cycletakes place. and initiation oftheir fruiting bodies (Schmidt, 1983; Pilz et In both cases, the Jife cycle is genetic and may al., 2007), their ecological interrelationships (Stamets, 2000) represent any class ofMorchella, since knowledge regarding and especially their Jifecycle, have limited their production. each individual species is scarce (Masaphy, 20IO) and the Furthermore, inMexico and LatinAmetica, few studies have challenge of their taxonomic identification is considerable beenconductedonthe genus Morchella. given the brief fruiting season and diversity of phenotypic Despite the scientific, ecological and commercial responses 10 different environmental conditions (Wurtz etal., appJications that represent the knowledge ofthe Jife cycle of 2005). Forexample, morels divide into only two phenotypes: Morchella, this has onlybeendescrlbedbyVolk and Leonard black(M angusticeps, M elata and M conica) andyellow or (1990) and Pilz et al. (2007). The former study proposed a white (M esculenta, M crassipes and M deliciosa) (Bames general cycle, identifying the stages ofvegetative myceJium, andWilson, 1998), although reddish-brown morels have been

AutorJHlra correspolldenclll: GeranIoMtJIII characterized, represented by M rufobrunnea (Guzmán and gerartlo."'ata@inecoLmx Tapia, 1998; Maaaphy el a/., 2009), lIIId 1heoe have beeD Masaphy el al. (2009), tbe SIlDW challenge exista for tlu:: confirmcld as being genetically distinct (Pilz I!t al., 2007; different typcs of MOI'CMlla. Ibis is probable bccausc, in Muapby,2010). ObservatiODS conducted during the procesa of sclerotia. Itisalso possible thatM escul6lta, M C1'Q!Jsipu and formation. no morphological differenceswere foundbcrtwcen M. deliciosa may be ecotypel oC the same apeci.es (Volk and M. e3Cf1Jenta and M. con;ca (Alvarado-Castillo el aJ., 2012). Leonant. 1990). Inthis sense, recent molecular phylogenetic The objcctive oftbis study wu thercfore to contributc to tbe

studies report al least SO &peCies worldwide, as well aa high mowledge oC Morchella through the generatioD of a continental endemism, witb 19 new species in ex.isteD.ce in theoretical life cyclc (Figure 1) that integrates existiD¡ NorthAmerica (Kuo el ul., 2012). However, there JI a certain models, experimental observations and research related to :margin of error in the phylogeD)' of M01'Ch~lla. lince onIy thisgenus.

77% ofthe lmown species have been sequenced and it has The cyelc begins with the matW'c BlCOCarp, tbe BIci been estimated tIlat 66% oC the sequences numbered in ofwhich contain eight ascospores (Miles and Chang. 1997)

GenIlaDk bavc beeD identified emmeoualy (Du elal., 2012). produoed by the crossiDg oCtwo baploid (o) nuclei, lo Cmm a Furtbermore, Morchella can modify its interactions diploid (2n) DUCleus that, followiDg meiosis, fo.r:ms new according ro ecological cireumstaDces; itcan be saprophytic. baploid ascospores (Ower el ul., 1988; Pi1z el al., 2007) that mycorrhizal or facultative (Buscot, 1992; Dahlstrom el al., are subsequently expuIse

A¡cocarp

Q • QO A¡cospore¡"" JI

P,imocdi. ..-'" ~ .. .. •.?~ 1 , O Knols or pinheads /' ",,'~ JI Conidia N ';>t t< ~C r Environmental ~factor! ' " i ! C"Po"m, my" mm , ~¡. , ~. , ¡ÚJ my"liom • ...... '%f;' º ------::."""'" •• . 4-'-';" '71my mycelium i""~.. ~~ \" Sc1erolia Sc1erolia \~' 1 Chla y ospores '-- II+JI. I • ____ ¡, ~-. JI ' . ~ v j,:»f!;:- :... /------.0. h~4 Ana¡lomo¡e¡ 1mperfce! paseh ",;¡{'' ..1\ ~'¡¡.'., _~ " / Secondary mycelium • Powdery mildew .'" "'" Fi¡ure 1. 1'heoretical1ife cycle oí the ¡enua Mascocarp, generating secondary or heterokaryotic bylhe production ofvegetative (myceliogenic) orcarpogenic (n+n) mycelium, lhe hyphae ofwhichcootainvarious haploid mycelium in order to produce ascocarps (Ower et al., 1986; nuclei(VolkandLeonard, 1989a;Pilzetal.,2007)tbatrange Volk and Leonard, 1989a; Bames and Wilson, 1998), lhe from 40-50 (Pilz etal., 2007) to 65 (Volk and Leonard, 1990) diíferentiation ofwhich is determined by a combination of per seplum, wilh an average of 10 a 15, conferring genetic, genetic and environmental factors, and which remains to be cytological and somatic stability (Volk and Leonard, 1989a). establishedinterms oflhesuccess offructification. In lhis way, it is capable of producing totally fertile Itshouldbenotedlhat a sclerotium does nor directly recombinantmeiotic progeny (ascospores) (pilz etal., 2007). diíferentiate into ascocarps but instead follows ooe of lhe Moreover, this genetic diversity can confer adaptability to a routes described. Similarly, it is not known whelher lhe wide range ofecological and environmental conditions (Volk sclerotia produced by primary mycelium can produce andLeonard, 1989b; Buscot, 1992). ascocarps (Volk and Leonard, 1990). Pilz et al. (2007) The secoodary mycelium passes through repeated indicate tbatthis is impossible, since its haploidnatore means branching and plasmogamy ofhyphae lhat compact to form tbat itproduces sterile structores lhat are incapable offruiting masses tbat grow and matore to create sclerotia (Volk and (allhough lhere are examples of haploid fructificatioos in Leonard, 1989b). During lhis process, lhey may form basidiomycetes).Likewise, lhepossibilitytbatlhemycelium ch1amydospores lhat give rise to andlor form par! of lhe (primary or secondary) could diíferentiate directly into sclerotia (Alvarado-Castillo et al., 2012). These asexual ascocarps, as in olher fungi (K.ües and Liu, 2000), remains to structores are a class of conidia (Ower, 1982; Ower et al., beexplored. 1986, 1988) produced by lhe modificatioo ofsimple hyphae The carpogenic mycelium produces structures and represent a means of clona! propagation (Amir et al., similar to nodes or pinheads tbat give rise to primordia lhat 1993; Pilz etal., 2007). Inlhe same way, lhe imperfect phase continue growing and diíferentiating to form fructifications

• (Masaphy, 2005). In tum, in lhe absence of appropriate Dahlstrom, 1.L., J.E. Smith, N.s. Weber, 2000. Myeorrhiza-like interaction by MorcheIla with speeies of the Pinaceae in pure culture conditions for growth and development, lhe primordia are synthesis. Myeorrhiza9:279-285. Du, XlI., Q. Zbao, Z.L. Yang, K. Hansen, H. Tllfkm, S. Buyukalaca, D. prone lo abortion (Ower, 1982; Volk and Leonard, 1990; Pilz Dewshury, J.M. Moncalvo, G.W. Douhan, V.A.R.G. Robert, S.A. Rehoer, AP. Rooney, S. Sin!<, K. O'Doonell, 2012. How well do el 2007).As in olher fungi, lhis indicateslhatlhe existence al., rrs rDNA sequenees differentiate speeies oí tme morels oftriggers for fiuctification is very likely (Rodriguez, 2007), (Morehella)? Mycologia 104(6):1351-1368. Gessner, R.V., 1995. Geneties and systematies of North Ameriean butlhat lhese are notclearly defined inlhe case ofMorchella populations of MorcheIla. Canadian Joumal of Botany 73(1):967--97l. (Gessner, 1995; Pilz elal., 2007). Greene, D.F., M. 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