CONICET | Buscador de Institutos y Recursos Humanos

In this study, actinomycetes isolates, isolated fromrhizosphere of wheat (Triticum aestivum L.), were screenedfor antagonistic activities on certain root rot fungi (Fusa-rium culmorum, Fusarium graminearum, Fusarium verti-cilloides and Bipolaris sorokiniana). The in vitro antago-nistic effects of actinomycetes isolates were determined onsolid media against fungal pathogens. The inhibition mecha-nism, effect of application time and pH on inhibition wasinvestigated. The actinomycete isolate 129.01 exhibited ahigh inhibition ratio of more than 60 % against all fungi. The activity of the isolate 129.01 against root rot fungi wastested under greenhouse conditions. The root rot score (1-10), mean plant height (cm) and mean weight of green partof plant (g) were determined after an incubation period.The root rot score of the infected plants was decreased sig-nificantly by this isolate, even if the plants were inocu-lated with all of the pathogen fungi together (P<0.05).The results indicate that isolate 129.01 could be useful asa biocontrol agent. The assignment of the isolate 129.01 tothe genus Streptomyces was supported by 16S rRNA analy-sis.