ارزیابی برخی جدایه‌های آنتاگونیستی از خاک‌های شور و خشک استان کرمان در برابر عامل پژمردگی خیار

Fusarium crown and root rot of cucumber caused by Fusarium oxysporum is one of the most important disease in cucumbe which results in significant losses in the yield of cucumber greenhouses. Cucumber is one of the vegetables that have little tolerance for water stress, so drought stress is a limiting factor for its growth. Plant growth promoting rhizobacteria (PGPR) affect plant physiology and biochemistry activity by different mechanisms, they also protect plants against pathogen attack and environmental stresses such as drought and salinity. The aim of this study was to evaluate the control of Fusarium crown and root rot of cucumber using the antagonistic bacteria were isolated from arid and salty areas of Kerman province. For this to purpose isolate the bacteria were prepared in a dilution series from the soil samples collected, then purified single colonies by the streak-plate technique. The antifungal activity of bacterial isolates against Fusarium oxysporum was carried out by dual culture assay. The results of the experiment showed that among the 130 isolates, 20 isolates had highest inhibitory effects on pathogenic fungi, were selected as superior isolates. In order to evaluation drought and salinity tolerance of selected bacteria, salinity and drought tolerance test were done in 0.5, 5, 7.5, 10 and 12.5% levels of NaCl and 32.6% of polyethylene glycol-6000 respectively. The results showed that among the 20 isolates, 3 isolates had the highest levels of drought and salinity tolerance. Further studies on the biocontrol ability of these isolates in greenhouse conditions are under consideration.