Antagonistic Bioactivity of Endophytic Actinomycetes Isolated from Medicinal Plants

Endophytic actinomycetes are promising biocontrol agents for use in agriculture and have been isolated from various plant species. In the present study, 40 endophytic actinomycetes were isolated from roots, stems and leaves of three medicinal plants viz. Aloe vera, Mentha arvensis and Ocimum sanctum. The identification revealed that the majority of the isolates were Streptomyces spp. and the rest were identified as Saccharopolyspora spp., Micromonospora spp. and Actinopolyspora spp. The dual tests revealed that nine endophytic actinomycete isolates displayed a wide spectrum activity against nine fungal phytopathogens. Out of 8 isolates, 90% inhibited the growth of at least one or more phytopathogenic fungi and Saccharopolyspora 0-9 (Out of 8 isolates, 90% inhibited the growth of at least one or more phytopathogenic fungi and Saccharopolyspora 0-9 exhibited antagonistic activity against Aspergillus niger, Aspergillus flavus, Alternaria brassicicola, Botrytis cinerea, Penicillium digitatum, Fusarium oxysporum, Penicillium pinophilum, Phytophthora dresclea and Colletotrichum falcatum.