Biological control of some pathogenic fungi by Bacillus subtilis Bs126

Among plant diseases, crown and root rots are very important in Iran. Phytophthora citrophthora and Fusarium oxysporum are two pathogens that damage different plants. In order to study the effect of Bacillus subtilis (Bs126), four antagonistic bacteria and benomyl fungicide were evaluated on Fusarium oxysporum. It was found that only Isolate 126 had significant difference and resulted in output increase and growth factors. Treatments had desirable effects either on pathogen or onion growth factors in greenhouse condition. Bacteria treatments were as the following isolates: 48 and CHA0 (Pseudomonas fluorescens), Isolates 52 and 22 (Bacillus cereus) and Isolate Bs126 (Bacillus subtilis). Indeed, the effect of some treatments was studied on Phytophthora citrophthora (the casual agent of pistachio gummosis). Experiments were carried out with 307 isolates collected from pistachio rhizosphere. After preliminary experiments, four highly effective isolates (8, 291, CHA0 and 126) were selected from these bacteria for subsequent studies. Greenhouse studies were carried out by using the antagonistic bacteria as soil treatment. Greenhouse studies in related to control of pistachio gummosis showed that Isolates 126 and CHA0 had the highest effect on increasing the growth factors and decreasing the percentage of mortality in sterile and non-sterile soils.

Keywords:

Biological control , Fusarium oxysporum , Phytophthora citrophthora , Bacillus subtilis , Pseudomonas fluorescens , Inoculum , Onion , Pistachio