Abstract
In assaying soil samples from 35 locations (610 samples/Prefecture) in Shikoku Island for Pythium species by a trapping isolation method with cucumber seeds as a baiting substrate, one to four taxa/sample were isolated from 33 samples, but Pythium was not isolated from two samples from Kagawa Pref. A total of 335 isolates were identified into 12 taxa including H-Zs, a provisional Pythium group with zoospore formation from hypha-like sporangia, but without sexual organs. Among these fungi, 134 isolates of P. sylvaticum obtained from 29 locations were the most dominant, followed by P. ultimum and P. spinosum.
