Identification and control the causal agent of root rot disease of cucumber in Iraq

صفاء نعمت حسين

doi:10.26389/ajsrp.n160319

Abstract

تم رصد مرض تعفن الجذور في حقول محصول الخيار في محافظتي ديالى وصلاح الدين في العراق. أظهرت نتائج العزل وجود فطريات تعود الى اثني عشر جنس. اظهر الفطر Fusarium solani اعلى نسبة ظهور بلغت 82.15% وبتكرار 54.00%. سبعة وسبعون عزلة شخصت على اساس صفاتها المزرعية والمظهرية بانها تعود للفطر F. solani، وخمسة وستون عزلة منها تضاعفت ايجابياً مع البوادئ المتخصصة للأنواع التابعة لجنس الفطر Fusarium باتباع تقنية تفاعل البلمرة المتسلسل. العزلة DF13 كانت الاشد ضراوة إذ بلغت نسبة انبات بذور الخيار في معاملاتها 0% مختبرياً. حققت عزلة بكتريا المكافحة الحيوية Bacillus pumilus نسبة تثبيط معنوية ضد العزلة DF13 بلغت 100% مختبرياً. وتحت ظروف البيت الزجاجي حققت العزلة B. pumilus خفض معنوي في نسبة المرض وشدته اذ بلغت 30.55% و 20.75% على التوالي مقارنة مع معاملة السيطرة السالبة التي بلغت 80.50% و 55.00% على التوالي.

Highlights

Root rot disease of cucumber (Cucumis sativus) is a prevalent disease causes highly economic losses of cucumber in Iraq and worldwide (Vakalounakis,1996)
Isolation and Identification the fungi associated with samples Samples from eight diseased cucumber fields were collected in the Diyala and Saladin governorates in April-May, 2018
Samples were cut into 0.5-1cm segments and washed under running tap water for 30 minute, surface sterilized in 1% sodium hypochlorite for 2 minute and cultured on the Potato Dextrose Agar (PDA) supplemented with 200 mg\l amoxicillin and incubated at 25±1C° for 7 days, single spore technique was made for each isolate

Summary

Introduction

Root rot disease of cucumber (Cucumis sativus) is a prevalent disease causes highly economic losses of cucumber in Iraq and worldwide (Vakalounakis,1996). Typical symptoms appear on the shoot system of the plants as a form of wilt and yellowing of the lower leaves and present of brown spots on the crown area which is in contact with the soil surface, and during the fruit holding wilt and yellowing extends towards the top of the plant with drying lower leaves and death of the plants, symptoms in root system appear as a rot in the main and subsidiary roots (Ayed et al 2007). Several fungal species reported to be causal agent of the root rot disease including Fusarim solani, Macrophomina phaseolina, Rhizctonia solani. Several spot in the world such as USA reported this disease and indicated that the fungus F. solani was the major causal agent (Snyder and Hansen, 1941). ITS-Fu-f and ITS-Fu-r, were used by Abd-Elsalam et al (2003) for identification of Fusarium spp

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