Saprolegnia milanezii sp. nov., a new species of Saprolegniales (Oomycota, Straminipila) from Brazil Author Rocha, Sarah Cristina Oliveira Instituto de Botânica, Núcleo de Pesquisa em Micologia, Av. Miguel Stéfano 3687, CEP 04301 - 012, São Paulo, SP, Brazil. Author Sandoval-Sierra, Jose V. Departamento de Micologia, Real Jardín Botánico-CSIC, Madrid, Spain Author Diéguez-Uribeondo, Javier Departamento de Micologia, Real Jardín Botánico-CSIC, Madrid, Spain Author Gonçalves, Danilo R. Instituto de Botânica, Núcleo de Pesquisa em Micologia, Av. Miguel Stéfano 3687, CEP 04301 - 012, São Paulo, SP, Brazil. Author Jerônimo, Gustavo H. Instituto de Botânica, Núcleo de Pesquisa em Micologia, Av. Miguel Stéfano 3687, CEP 04301 - 012, São Paulo, SP, Brazil. Author De Jesus, Ana L. Instituto de Botânica, Núcleo de Pesquisa em Micologia, Av. Miguel Stéfano 3687, CEP 04301 - 012, São Paulo, SP, Brazil. Author Marano, Agostina V. Instituto de Botânica, Núcleo de Pesquisa em Micologia, Av. Miguel Stéfano 3687, CEP 04301 - 012, São Paulo, SP, Brazil. Author Pires-Zottarelli, Carmen L. A. Instituto de Botânica, Núcleo de Pesquisa em Micologia, Av. Miguel Stéfano 3687, CEP 04301 - 012, São Paulo, SP, Brazil. text Phytotaxa 2016 2016-08-24 270 4 286 294 http://dx.doi.org/10.11646/phytotaxa.270.4.5 journal article 302214 10.11646/phytotaxa.270.4.5 9a12960f-d4e1-4f3e-947b-4a98a960296f 1179-3163 13661020 Saprolegnia milanezii Pires-Zottarelli C.L.A. & Rocha S.C.O. sp. nov. ( Figs. 1 , 2 ) MycoBank number : MB817658. Holotype : − BRAZIL . São Paulo : Cananéia city, “Parque Estadual da Ilha do Cardoso”, isolated from freshwater of the Perequê river (“ Poço das Antas ”), 20 February 2013 , SP446402 ( Specimen permanently preserved in a metabolically inactive state: parts preserved in absolute ethanol); ex-holotype in CCIBt 4001; ex-isotype in MMBF 02 /16. GenBank accession number ITS KX528018, and LSU KX528019 . FIGURE 1 . Saprolegnia milanezii . A. Empty fusiform zoosporangium. B. Zoosporangium with internal proliferation and primary zoospore discharge. C. Basipetal renewal of the zoosporangium. D. Gemma functioning as zoosporangium. E. Proliferous gemmae. F. Gemma with several tubes for zoospore discharge. Scale bar = 10 μm. FIGURE 2 . Saprolegnia milanezii . A. Oogonium with oospheres and diclinous antheridium. B. Oogonia with diclinous and monoclinous antheridia and abortive oospheres. C. Extended stalk near the oogonium septum. D. Oogonium with one pit and subcentric oospores. E. Oogonia branched in racemous fashion. F. Catenulate oogonia and subcentric oospores. Scale bar = 10 μm. Additional specimens: − BRAZIL . São Paulo : Cananéia city, “Parque Estadual da Ilha do Cardoso”, isolated from freshwater of the Perequê river (“Riacho cor de chá”), 20 February 2013 , SP446403 (Specimen permanently preserved in a metabolically inactive state: parts preserved in absolute ethanol), culture strain CCIBt 4027 and MMBF 03/16. GenBank accession number ITS KX528020, and LSU KX528021. Description: − Zoosporangia typically scarce, terminal, fusiform and/or filiform, 113.8±38.3 × 27.3±5.6 μm (overall range 70.0−180.0 × 17.5−40.0 μm); renewed internally or by cymose branching, and also not rarely growing through the empty ones. Zoospore discharge saprolegnoid. Zoospores dimorphic; encysted zoospores 10.0±02.5 (overall range 7.5−12.5 μm). Gemmae present, spherical, some irregular, functioning directly as zoosporangia, germinating and forming new mycelia or differentiating into functional oogonia. Oogonia terminal, some intercalary, lateral and sessile, pyriform 75.6±16.5 × 50.0±08.1 μm (overall range 55.0−100.0 × 42.5−65.5 μm), occasionally spherical, 63.0±16.0 (overall range 45.0−97.5) μm diam., some in a racemous fashion, rarely catenulate; smooth-walled, pitted; oogonial stalks ½−7 times the diameter of the oogonium in length, some extended near the oogonium septum. Oospheres normally maturing, sometimes abortive. Oospores subcentric, spherical, 32.0±05.5 (overall range 22.5−42.5 μm), filling the oogonium, 1−6 (12) per oogonium. Antheridia scarce, monoclinous and diclinous; antheridial branches branched; antheridial cells simple, attached apically; fertilization tubes not observed. FIGURE 3 . Phylogenetic relationships of Saprolegnia milanezii based on ITS and LSU rDNA regions. Phylogenetic tree was obtained from Bayesian inference and shows the relationships among S. milanezii and related Saprolegnia species. The numbers in the branches represent the probability values (>0.95) and bootstrap support (> 75) obtained from Bayesian inference and maximum likelihood analyses, respectively. Notes: −Characteristics of this species includes the frequent formation of structures resulted from the growth of germinating gemmae, and also the late maturation of the oospheres probably related with the rare presence of antheridia. This species presented high variation in its morphological characteristics, such as the absence of asexual reproduction after long time of preservation.