Sahel Bange Zare - Graduate Student, Department of Plant Protection, Faculty of Agriculture, University of Mahabad
Nabi Khezrinejad - Department of Plant Protection, Mahabad Branch, Islamic Azad University, Mahabad, Iran

Background and Aim:phytophthora root and crown rot of cucumber is one of the most important soil born disease worldwide. This study was carried out to identify and investigate the potential antagonistic bacteria for control of disease in West Azerbaijan province.Methods:For this purpose, pathogen was isolated on a semi-selective culture medium of CMA-PARP. 20 isolates recovered from various parts in West Azerbaijan province. isolates were identified as Phytophthora drechsleri on the selective medium based on morphological and growth characteristics in different temperatures. for isolation and identification of cucumber rhizospheric bacteria healthy cucumber samples and their rhizospheric soil were taken from different cities. Samples immediately transferred to laboratory. One gram soil of rhizosphere added to 9 ml sterile distilled water. Suspension serially diluted and cultured on NA. single colonies were selected basis on morphology and purified. Antagonistic effect of the strains was evaluated based on their growth inhibitory of pathogen.To screening and assessment bacterial strains potential antagonistic ability, dual culture test were conducted on PDA+NA media. After 24 hours fungal disc transferred to center of plate containing bacteria and sealed. After few days inhibitory zone diameters were measured.Results:Among 45 isolates, 6 had strong inhibitory zone. Based on phenotypic characteristics the strains B1, B2, B8, B10, B15 and B20 were identified as Bacillus sp., Pseudomonas putida, B. cereus, Achromobcater sp., P. fluorescens and Paenibacillus polymyxa, respectively.Conclusion:Biological control by bacteria was reported formerly, In this study good results obtained in vitro condition and bacteria includes gram positives and gram negatives.

biological control, soil born disease, public safety