Virology & Mycology
Open Access
ISSN: 2161-0517
+44 1223 790975
ISSN: 2161-0517
+44 1223 790975
Lubna Al-Zubaidi and Safaa Hussein
University of Al Mustansiriayah, Iraq
Posters & Accepted Abstracts: Virol Mycol
Tomato (Lycopersicon esculentum) belongs to solanaceae family, it is an important vegetable crop. Drechslera halodes (Drechsler) Subram and B. L. Jain is a common plant pathogen fungus causing leaf spot, crown and root rot disease of several plant species including tomato worldwide. Isolation from infected tomato plants from three provinces in the middle and south of Iraq were Babil, Karbala and Wasit demonstrated the presence of the pathogen. D. halodes was predominant while appeared in 83.33% of the samples with frequency of 50.25%. Pathogenicity test of 55 isolates of the fungus were estimated on tomato seedling under greenhouse conditions and the results indicated that all of the isolates were pathogenic, the isolate Kkd- 6 exhibited maximum values of disease severity of the shoot and root system were 88.33%, 92.85% respectfully compared with control which was 0%. Biocontrol agents were collected from the rhizosphere of the healthy tomato plants, sixty four bacterial isolates were isolated and purified, antifungal activity of the bio-agents were carried out using dual culture technique on the potato dextrose agar, four isolates of them were Wb-12, Kb9, Bb18 and Kb-18 significantly reduced the mycelial growth of the pathogen in vitro, while exhibited 14.28% antagonism efficiency, identification of the bio-agents using Vitek 2 compact system technique showed that isolates Wb-12, Kb-9 belong to Bacillus subtilis isolate Bb-8 belong to Enterococcus columbae and isolate Kb18 belong to Pseudomonas putida. Under greenhouse conditions all of the bio-agents were reduced significantly the percent of disease incidence to 5-10% and severity of shoot and root system to 5.00-8.33%, 2.14-7.14% respectfully compared to control which exhibited 100% disease incidence and severity of shoot and root system of 90.00%, 93.57% respectfully. It appears that the disease of the leaf spot, crown and root rot disease is spread widely in the tomato growing area in Iraq control the disease using local isolates of the rhizobacteria consider as one of the most friendly ecosystem method of disease management, since the indiscriminate uses of the pesticides raised the resistance of the pathogen against the active substance of the pesticides. This is first report of Drechslera leaf spot; crown and root rot disease of tomato in Iraq.
Email: lubna_alzoubaidy@yahoo.com