Phylum：Oomycota　>>　Class： Oomycetes　>>　 Order： Saprolegniales 
   
 
　BCRC Number： NO BCRC Number!  
   
　Scientific Name： Pythiopsis subcentrica
 
   
   
　Author：

Pythiopsis subcentrica Chiou & Chang sp. nov.
   
 
 
 
 
　Description： Hyphae vegetativae delicatae. Zoosporangia elongate; zoosporae emissae, ex orificio zoosporangium natantes; zooporangia seconda intra prima vel subter vel latere formata. Zoosporae monoplaneticae. Oogoniis copiosis, sphaericis, vel plures papillas habentibus, ant irregularibus;27-41 μ in diam, plerumque 30-35 μ excl papillis. Tunica oogoniorum non-punctulate, Oosporis 22.5-(26-30)-35 μ, sphaericis, subcentricae vel centricae, quae singualis in oogoniis. Rami antheridiales abundant, exurgentes immediate infra oogonium, guorum antheridia non persistent.Vegetative hyphae slender, much branched, 10-30μ in diameter, thickest at the terminal. Zoosporangia rate or moderately abundant; 100-400 × 20-30 μ; sporangia renewed by lateral branches, rarely internal branches, rarely internal proliferation. Zoospores discharge saprolegnoid,pip shaped with two apical cilia sprouting by germ tube after the first encystment(monomorphic). Gemmae abundant, spherical, elongate, or irregular; single or catenulate. Oogonial wall thin, unpitted and more or less papillate; 27-(30-35)-41 μ exclusive of papillae. Immature oogonia possessing a conspicuous mucilage layers. Oosphere maturing. Oospores subcentric,rarely centric; one in the oogonium, 22.5-(26-30)-35 μ in diameter. Antheridial branches abundant, arising from immediately below the oogonium, antheridia not persistent.
 
 
 
 
 
　Specimens：

Type locality: Taipei, Yang-ming Shan; garden soil; April 1, 1974. Type specimen: Type culture is deposited in the herbaria of Inst. of Botany, Academia Sinica.
 
 
 
　Habitat： Soil and water
 
 
 
　Distribution：

Yang-ming shan Taipei
 
 
 
　References：

Sparrow FK Jr. 1960; Ziegler AW. 1958.
   
   
   
　Provided：

T. S. Chiou and H. S. Chang
 
 
　Note： Base on monomorphic zoospore, saprolegnoid spore discharge and immature oogonial wall possessing a conspicuous mucilage layer, just as Pythiopsis terrestris (H?hnk) Chiou &Chang, we identify this isolate to be a species of Pythiopsis, but this isolate can be distinguished from P. terrestris by having larger oogonia and oospores. Moreover the antheridial branches of this isolate were abundant and arose mainly from immediately below the oogonium. So we believe that they are not the same species.Pythiopsis subcentrica can be separated from other members of Pythiopsis by possessing subcentric oospores, elongated sporangia and much branched sexual reproductive hyphae. Sowe suggested that Pythiopsis subcentrica is a new species of Pythiopsis.