Antifungal Activity and Genetic Diversity of Selected Endophytic Fluorescent Pseudomonads

Abstract

Fluorescent Pseudomonads have been effectively utilized for controlling major fungal plant diseases because of their antifungal metabolites. In this study, thirty-four bacterial isolates were isolated from root samples of different crops and screened as potential biological control agents against Rhizoctoniasolani AG 2-2, Pythium arrhenomanes and Fusarium solani. On the basis of dual culture assays, twenty isolates were selected for phenotypic characterization, identification and plant growth promoting traits; four isolates were selected for greenhouse studies. The selected Pseudomonas strains were characterized by PCR methods using rpob primer. Eight showed the ability to produce indole acetic acid (IAA) while 12 isolates have no IAA produced, thirteen isolates could solubilize inorganic phosphate and six strains produced hydrogen cyanide. Tested Pseudomonas strains had positive response on bean growth and health.Obtained results indicated that the tested antagonistic fluorescent pseudomonads reduced disease severity in beans and disease development under greenhouse pot experiment. However, further study is needed to apply to these results under field conditions.