المكافحة الحيوية للفطور الممرضة المرافقة لحبوب الرز

الملخص EN

This research was carried out to evaluate the efficiency of some antagonistic microorganisms, fungi and bacteria: Trichoderma harzianum, T.

pseudokoningii, Aspergillus niger, A.

candidus, Penicillium sp., Bacillus cereus, and two isolates of Pseudomonas aeruginosa(I&II), to inhibit the pathogenic fungi associated with rice seeds.

Results showed that all antagonistic organisms inhibited the pathogenic fungi except R.

stolonifer whose growth decreased only in response to the bacterial treatment.

It was found that the culture filtrates of the antagonistic microorganisms, T.

harzianum, the two species of Aspergillus and the two isolates of P.

aeruginosa reduced significantly the radial growth of the associated fungi grown on PDA.

The culture filtrates of the antagonistic organisms also reduced the mycelium dry weight of the pathogenic fungi, and the filtrates reduced spore germination and germ tube elongation.

The treatment of rice seeds with antagonistic organisms or its filtrates did not have any negative effect on seed germination except the treatment with Penicillium sp.

which reduced rice seed germenation, but the filtrates reduced the number of fungi associated with seeds which was determined on the basis of infected seeds