Isolation and Identification of Endophytic Actinomycetes and their Antifungal Activity

Actinomycetes endophytes are promosing biological control agents for use in agriculture and have been isolated from various plant species. In the present study, 36 endophytic Actinomycetes were isolated from roots, stems and leaves of healthy tomato plants. The identification revealed that the majority of the isolates were Streptomyces and the remaining were identified as genera Microbispora and Nonomurae, which was the first time found as endophyte. To determine the antifungal activity of the isolates, 28 isolates were subjected to in vitro assay against six fungal pathogens. All the isolates tested inhibited the growth of at least one of the phytopathogenic fungi and that 5 of the isolates inhibited the growth of all the fungal pathogens used in this assay. Selected isolates were tested for their activity in planta in pot experiments against Rhizoctonia solani. Of the 15 isolates tested, 14 isolates significantly reduced (p<0.01) the percentage of Rhizoctonia solani infected plants from 30 to 76%.