SOME PHYSICAL AND CHEMICAL FACTORS AFFECTING ASEXUAL REPRODUCTION OF 3 PYTHIUM SPP

Pythium aphanidermatum produced zoospores most abundantly at 15 degree s C, whereas the optima for P. oligandrum and Pythium ''group F'' were 15 and 25 degrees C, respectively. The optimum temperature of mycelia l growth was 30 degrees C for all species tested. Optimum pH for mycel ial growth and zoospore production was 7 for tested fungi. Moderate os motic potentials (-0.13 similar to-0.27 MPa) appeared to favour either mycelial growth or zoospore production. Low salinity (0.1 similar to 0.5 % NaCl) was satisfactory for mycelial growth and zoospore producti on.