التأثير المضاد لعزلات بكتيرية من المحيط الجذري لنبات القمح في أنواع من فطر الفيوزاريوم المسبب لمرض تعفن الجذور

الملخص EN

Wheat root rot has spread widely in the word; it has been recorded in a number of Syrian provinces .

The root rot disease of wheat is the most important diseases affecting wheat crop .

250 bacterial strains were isolated from the wheat rizosphere.

8 bacterial isolates belonged to the genus Bacillus were antagonists in laboratory test to the most important casual wheat root rot Fusarium culmorum, Fusarium graminearum and Fusarium spp.

The results showed that the effect of bacterial isolates different from one fungus to the others .the bacterial isolates Ba 22: 3, W4, W8 showed height effect on fungal F.graminearum isolates .The antagonist distances were (4,3.6,3.6) mm respectively , after sixth day of the test , where as the W7 isolate showed the less effect which was(2) mm .The effective of the rest isolates were between (2-3) mm, The bacterial isolates W4, W5, W6 were the most effective on fungal F.culmorum ..

As isolates whereby The antagonist distances were between (3.3,4.7, 3.7 ) and the less effective isolate is the isolation 9: 3 (1) mm.

either the effect of the rest of the isolates were between (1.3 to 3.3 ) mm .

For the fungus Fusarium spp.

was the best effect of isolates were W4, W5, W6, W7 The antagonist distances were(5.7,5.7,6,5.7) mm, the less effective of the isolates were 9: 3 and Ba 22: 3 (0 ) mm.

The other 20 isolates were tested and showed antagonism to white rot disease on garlic Sclerotinia cepivorum.

7 isolates of which belong to the genus Bacillus, pseudomonas, pantoea showed antagonist on wheat fungus .

the antagonism distances were measured a between bacterial culture and fungals and they were ( 2) mm for isolate (T131) and (3.3) mm for tow isolates ( G 11: 1 and 39) for the fungus F.graminiarum,( 1) mm for isolate (G11: 1) and (4) mm for isolate (H) for fungus F.

culmorum