Isolation and identification of a virulent Ralstonia solanacearum by fliC gene amplification and induction of chitinase by 2-amino butyric acid for control of bacterial wilt in tomato plants

Abstract

Ralstonia solanacearum is a devastating, soil borne bacterial pathogen of tomato. The pathogen is nonmotile in planta but highly motile in culture. On the basis of physiological and biochemical characteristics 26 isolates have been purified and identified as Ralstonia solanacearum. The flic gene is responsible for the movement of bacteria. Ralstonia specific fliC gene amplification is the indication of virulence of the pathogen. In the present study one R. solanacearum isolate has been identified by PCR amplification of the fliC gene using fliC gene specific primer. Following isolation and identification of the virulent isolate, fresh tomato plants were induced by application of 2- amino butyric acid (ABA). The defense enzyme, chitinase was estimated in treated plants. Treated inoculated plants did not show any visible symptoms of wilt even after 14 days of inoculation. Significantly it was observed that chitinase was increased in the 2-ABA-treated plants and also in the treated-inoculated plants. The increased chitinase activity in the treated plants showed that 2-ABA has the resistance inducing capacity in tomato plants against Ralstonia solanacearum.