مسح حقلي لمرض تعفن الجذور الشائع على القمح و الشعير في محافظتي حلب و إدلب (شمال سورية)‎

الملخص EN

A survey of common root rot disease was conducted in the major cereal- growing areas in northern Syria in 1999 and 2000 to determine its incidence, disease index, and causal organisms.

Results showed that the disease incidence and disease index were relatively higher in Aleppo governorate than in Idleb governorate in both years.

It was also observed that barley fields were more affected by common root rot disease than wheat fields in both areas and years.

Isolation from infected roots showed a disease complex including Bipolaris sorokiniana (Sacc.

In Sorok.) Shoem.

and Fusarium spp.

The level of infestation with the first fungus was higher in barley fields in Aleppo governorate than the second fungus, which was more prevalent in wheat fields in Idleb governorate in both years.

Thirty-eight isolates of Fusarium spp., representing 11 groups, were easily recognized based on the color of fungal colony.

These isolates differed in pathogenicity.

Out of that, 8 isolates were nonpathogenic, whereas 29 isolates could infect at least one line of wheat or barley.

However, one isolate was able to infect all genotypes tested.

Cultural and microscopic characteristics of colonies were studied.

A high and significant (r = + 0.8) relationship (P = 0.01) was evident between the isolates pathogenicity on barley lines and the colony growth rate, whereas the relationship (r = + 0.41) was low and significant (P = 0.05) on wheat varieties