K Sowndhararajan1, S Marimuthu, S Manian. 1. Department of Botany, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, India.
Abstract
AIMS: The present study was carried out to screen the phylloplane bacteria from tea for antagonism against grey blight caused by Pestalotiopsis theae and blister bight caused by Exobasidium vexans and to further evaluate the efficient isolates for disease control potential under field condition. METHODS AND RESULTS: A total of 316 morphologically different phylloplane bacteria were isolated. Among the antagonists, the isolates designated as BMO-075, BMO-111 and BMO-147 exhibited maximum inhibitory activity against both the pathogens under in vitro conditions and hence were selected for further evaluation under microplot field trial. Foliar application of 36-h-old culture of BMO-111 (1 × 10(8) colony-forming units ml(-1) ) significantly reduced the blister blight disease incidence than the other isolates. The culture of BMO-111 as well as its culture filtrate effectively inhibited the mycelial growth of various fungal plant pathogens. The isolate BMO-111 was identified as Ochrobactrum anthropi based on the morphological and 16S rDNA sequence analyses. CONCLUSIONS: It could be concluded that the biocontrol agent O. anthropi BMO-111 was effective against blister blight disease of tea. SIGNIFICANCE AND IMPACT OF THE STUDY: Further study is required to demonstrate the mechanism of its action and formulation for the biocontrol potential against blister blight disease of tea.
AIMS: The present study was carried out to screen the phylloplane bacteria from tea for antagonism against grey blight caused by Pestalotiopsis theae and blister bight caused by Exobasidium vexans and to further evaluate the efficient isolates for disease control potential under field condition. METHODS AND RESULTS: A total of 316 morphologically different phylloplane bacteria were isolated. Among the antagonists, the isolates designated as BMO-075, BMO-111 and BMO-147 exhibited maximum inhibitory activity against both the pathogens under in vitro conditions and hence were selected for further evaluation under microplot field trial. Foliar application of 36-h-old culture of BMO-111 (1 × 10(8) colony-forming units ml(-1) ) significantly reduced the blister blight disease incidence than the other isolates. The culture of BMO-111 as well as its culture filtrate effectively inhibited the mycelial growth of various fungal plant pathogens. The isolate BMO-111 was identified as Ochrobactrum anthropi based on the morphological and 16S rDNA sequence analyses. CONCLUSIONS: It could be concluded that the biocontrol agent O. anthropiBMO-111 was effective against blister blight disease of tea. SIGNIFICANCE AND IMPACT OF THE STUDY: Further study is required to demonstrate the mechanism of its action and formulation for the biocontrol potential against blister blight disease of tea.