Contribution to physiological and biochemical diagnostics of Fusarium taxa commonly isolated in Egypt.

摘要

Fusarium isolates belonging to 24 species and 8 sections were subjected to 11 growth, physiological and biochemical tests (166 isolates). All species were able to grow on 25% Glycerol nitrate agar (G25N), Mannitol medium, Czapek iprodione dichloran agar (CZID) and Dichloran chloramphenicol peptone agar (DCPA). Growth rate, colony colour and reverse on G25N and CZIDwere promising diagnostic criteria for separating species within sections. The growth rate and reverse on Mannitol agar was diagnostic not only for separation of F. oxysporum from F. solani, but also for separation of many other Fusarium species treated. The ability to grow on Tannin-sucrose agar could distinguish some species of sections Liseola and Sporotrichiella. Acid production on Creatine-sucrose agar distinguished some species of section Liseola and F. trichothecioides of section Discolor. Acetylmethylcarbinol production revealed for the first time that all isolates of F. subglutinans can produce this substance, while most remaining isolates lacked this ability. Tests for peroxidase, urease and pyrocatechol oxidase proved to be very useful. The phosphatase enzyme seems to be common in Fusarium species and therefore it is only diagnostic for F. camptoceras (negative results). Some physiological features could be used as criteria to distinguish some sections or species within the same section.