identification of soil pythium species in fars province of iran

during 2000-2001, soil pythium species were studied in fars province. soil samples werecollected from various parts of the province (abadeh, bajgah, bayza, borazjan, darab, estahban, fasa,khafr, sepidan, shiraz, moharloo, and zarghan). isolates were recovered from soil by baiting. specieswere identified based on morphological characters of sexual and asexual organs, growth rate at differenttemperatures, and colony morphology on various media. from 270 isolates of pythium recovered, 12species and two groups were identified as: p. aphanidermatum*, p. aquatile, p. deliense, p. diclinum, p.echinulatum, p. inflatum, p. okanoganense, p. oliganderum, p. orthogonon, p. ostracodes, p. rostratum,p. vexans, pythium group “g”*, and pythium group “hs”* (species with asterisk were predominant).p. aquatile, p. diclinum, p. echinulatum, p. inflatum, p. okanoganense, p. oliganderum, p.orthogonon, p. ostracodes, p. rostratum, and p. vexans are new for fars, and p. aquatile, p.echinulatum, p. inflatum, p. okanoganense, p. orthogonon, p. ostracodes, and p. rostratum are new foriran flora.a key is also presented for identification of fars pythium species.