Antifungal activity of a new Streptomyces griseoruber isolated from banana Rhizosphere soil

Abstract

Fusarium wilt is a disease reducing significantly on banana productivity. The disease is caused by Fusarium oxysporum f.sp. cubense that attacks most of banana variety in the world. Biocontrol of the disesase has been being developed within the last decades such as the use of Actinomycetes. This research is aimed to isolate and identify antagonistic actinomycetes against Fusarium oxysporum f.sp. cubense. Actinomycetes were isolated from rhizospheric soils of banana plants with and without Fusarium wilt symptom. Antagonistic activity was carried out by dual culture method for selecting among isolates. Actinomycetes isolates showing higher antagonistic activity were subjected for morphological and molecular identification. Molecular identification was performed by sequencing of 16S rDNA gene. The research also found three isolates having higher antagonistic activity rather than the others. The three isolates, AcB60, AcB21and AcB32 was identified as Streptomyces griseoruber, Streptomyces chrysomallus and Streptomyces alanosinicus respectively. Fusarium wilt of banana, caused by Fusarium oxyspoum f. sp. cubense (Foc), is one of the most important and destructive diseases of banana, and is known to be a major biotic limiting factor for the development of the present banana industry. Biocontrol on the destructive disease, the use of antagonist as biocontrol agents (BCAs) against Foc, constitutes an effective option for the management of the disease.