A comparative study of Phialophora radicicola, an avirulent fungal root parasite of grasses and cereals.

摘要: SUMMARY The biology and infection-behaviour of a typical isolate Phialophora radicicola Cain have been compared with those representative Ophiobolus graminis (Sacc.) Sacc. Both species can utilize nitrate source nitrogen both require thiamine biotin for growth on inorganic nitro-gen; P. radicicola, but not O. graminis, was able to synthesize when grown asparagine as source. The pH range good in nutrient solution narrower than that its rate agar only one-third. the more active decomposer cellulose, cellulolysis adequacy index I.66 com-pared value 0.33 0. graminis. In agreement prediction from Garrett's (I966) hypothesis index, saprophytic survival wheat straw shortened by additional soil nitrogen, which prolongs graminis.P. found spread ectotrophically over roots wheat, oats barley runner hyphae indistinguishable cortical infection caused no necrosis discernible check infected cereals, nor any significant decrease grain yield inoculated maturity. Pre-existing retarded graminis; inoculation several grass reduced extent following grasses.