Plectospira myriandra Drechsler (1927: 294)

Jerônimo, Gustavo Henrique, Jesus, Ana L., Rocha, Sarah C. O., Gonçalves, Danilo R. & Pires-Zottarelli, Carmen L. A., 2017, New insights into Plectospira genus (Oomycetes, Straminipila): morphological and molecular analyses, Phytotaxa 307 (3), pp. 191-198 : 195-196

Plectospira myriandra Drechsler (1927: 294)

Fig 2. A–J

Mycelium dense; hyphae slender, sparingly branched. Inflated elements of sporangia abundant, which produces a long tube to release the zoospores. Zoospores forming an evanescent cluster in exit orifice and encysting with usually 8–11 μm diam. Gemmae absent. Oogonia mostly laterally, rarely terminal on short branches, smooth, spherical, 20–30 μm diam., provided with wall of 1.0–2.0 μm in thickness. Antheridia always present, diclinous, rarely monoclinous, ranging from 2 to 15 or more. Oospore single, yellow, subcentric, spherical, 13.7–22 μm in diam.

Specimen examined: — BRAZIL. São Paulo: Cananéia, “Parque Estadual da Ilha do Cardoso (PEIC)”, from soil sample, 20 August 2012, CCIBt 3992.

Notes: —The isolates CCIBt 3992 and CCIBt 3372 ( Jesus et al. 2013) of Plectospira myriandra presented all characteristics mentioned in its original descriptions ( Drechsler 1927), and are in agreement with other three studies previously published in Brazil ( Rocha 2006, Gomes et al. 2003, Miranda & Pires-Zottarelli 2012). In addition, the features mentioned above, which are shown in Table 2 and Figure 2 , were crucial for a correct identification of this species.

Figures

FIGURE 2. A–J. Plectospira myriandra. A–E. Plectospira myriandra CCIBt 3992. A. Lobulated zoosporangium. B. Oogonium and subcentric oospore. C. Oogonium showing pellucid spot (ps). D. Oogonium showing scattered pits in the wall (pw). E. Oogonium and abundant antheridia. F–J. Plectospira myriandra CCIBt 3372. F. Lobulated zoosporagium. G. Oogonium and antheridia. H. Oogonium and pellucid spot (ps) showed in indirect focus (arrow). I. Oogonium and subcentric oospore. J. Oogonia with pellucid spot indicated by the arrow. ps: pellucid spot. pw: scattered pits in the wall. Bars: 10 μm.