Exploiting plant growth-promoting Amycolatopsis sp. for bio-control of charcoal rot of sorghum (Sorghum bicolor L.) caused by Macrophomina phaseolina (Tassi) Goid
One strain of Amycolatopsis sp. BCA-696, a rare genus of actinomycete, demonstrated previously for its plant growth-promotion traits in chickpea and sorghum, was tested for its antagonistic potential against Macrophomina phaseolina (the causal agent of charcoal rot disease of sorghum) by dual culture assay, metabolite production assay and in greenhouse and field screens. In the dual culture and metabolite production assays, BCA-696 inhibited the growth of M. phaseolina. When BCA-696 was tested for its antagonistic activity under greenhouse and field conditions (two seasons) against charcoal rot of sorghum by tooth pick method of inoculation, it significantly reduced the disease. Scanning electron microscope analysis revealed that the xylem and phloem tissues of the BCA-696 treated stem samples were intact compared to that of disease control plants. This study indicates that the selected Amycolatopsis sp. BCA-696 has the potential to manage charcoal rot of sorghum.