Can you tell us where it has been sampled ? it looks like my favorite oomycete (A. euteiches) in the petri dish but I am not convinced by the microscopic pic.
so I may suggest Phytophthora (tropicalis ?). But as suggested by Jorge Noel, only molecular biology will bring you the answer . Use Oomycete or Fungi universal primers for your PCR before sequencing.
Micrograph shows the hyphae with the terminal (or peak) forms of chlamydospores, I do not see any vegetative spores. What kind of medium did you use to cultivate this fungus? What color was the reverse? You can use SNA mineral medium for stimlulation of sporulation
Second possibility is an information about microfungi contamination of root of Catharanthus roseus. Kemunting cina (Catharanthus roseus) is a tropical plant was important as medicinal plant from Apocynaceae family. It was cultivated mainly for its alkaloids due to the presence of indispensable anti-cancer, drugs, vincristine and vinblastine. The content of alkaloid in root of the plant is the main source of anti-hypertension.I have received an information about contamination of Catharanthus roseus by Fusarium oxysporum (see attachment).