Effect of Morinda citrifolia extracts on in-vitro growth of Ralstonia solanacearum

Abstract

Bacterial wilt is a major disease in solanaceaous plants caused by a bacteria called Ralstonia solanacearum. It affects large verities of solanaceaous plants worldwide. With an aim to develop effective antibacterial agent without any residual affect, the present study was conducted to analyze the in-vitro antibacterial potential of Morinda citrifolia against two different isolates of Ralstonia solanacearum. The Morinda citrifolia leaf and fruits were collected, dried and extracted using acetone and chloroform. The antibacterial activity of the extracts was assayed by using disc diffusion method. The results revealed that the average zone of inhibition of the leaf extracts was more in the chloroform extract (24mm) than in the acetone extract (23.5mm). However, no significant difference was observed with both the extracts. The fruit acetone extract produced 16.5mm zone of inhibition while the fruit chloroform extract produced 16mm zone of inhibition. The overall inhibitory activity of the leaf and fruit extracts against Ralstonia solanacearum (RSN6) isolate showed that 58.82% of the antibiotics produced less inhibitory activity than the fruit and leaf extracts. The inhibitory activity of leaf and fruit extracts against Ralstonia solanacearum (RSN12) isolate showed that 70.59% of antibiotics produced less inhibitory activity than the fruit and leaf extracts of Morinda citrifolia. The results revealed that both the extracts have produced inhibitory activity against Ralstonia solanacearum and the same could be used to extract antibacterial compounds. The potential of Morinda citrifolia extracts was found much better than most of the antibiotics