دور العزلات غير الممرضة من الفطر Rhizoctonia spp في مكافحة الأمراض المتسببة عن الفطر Rhizoctonia solani و تشخيص مجاميع الاندماج السايتوبلازمي بطريقة الزرع المزدوج على الشرائح الزجاجية

Abstract EN

In this study, 32 isolates of Rhizoctonia has been isolated from several host plants belonging to different geographic areas from Basrah and recipes all isolates were identical to the species R.

solani, R.

solani isolates was named Rs2 - Rs32 and the Binuclear R.

solani isolate was named BRs15.

Based pathogenicity test the results showed that all isolates were significantly reduced in the percentage of seeds cabbage germination ranged 0-66.7%, while BRs15 isolate (96.7%) did not showed significant differences compare with the control treatment (100%).

Six isolates (Rs2, Rs5, Rs9, Rs16, Rs27 and Rs29) with a higher pathogenesis belonging to different host plants were selected for further studies.

The results of identification of anastomosis groups showed that Rs5, Rs16, Rs27 and Rs29 isolates are belong to AG2 group, while Rs2 and Rs9 isolates are belong to other groups.

Binuclear isolate of R.

solani indicated that BRs15 isolate have reduced the negative impact of all pathogens isolates and provided good protection for cotton plants from infection of R.

solani since the percentage germination of seeds were increased and damping-off percentage were decreased.