Biological control of bacterial wilt disease of tomato caused by Ralstonia solanacearum by using isolated endophytic bacteria, Burkholderia cepacia, from tomato stems in vitro and in vivo

Ralstonia solanacearum is the cause of tomato bacterial wilt. Under favorable environmental conditions, it can cause rapid wilt and a lot of damage, and there is no practical remedy for it. The aim of this study was to separate endophytic bacteria B. cepacia from tomato stems of local cultivar and then to study the biocontrol effect of this bacteria against the bacterial wilt of tomatoes.
In this study four endophytic bacteria from tomato stem were isolated. Then after identification with bacteriology standard tests in order to investigation of their antagonistic effect and also effect on the growth rate of the plant in vitro with seed diffusion agar method were examined. Result of biochemical tests showed that all of endophytic bacteria which isolated from tomato stem were B. cepacia. In in vitro condition on the seed with B. cepacia bacteria in medium containing R. solanacearum bacteria showed the formation of 2- to-4.5 –mm haloes. In greenhouse conditions, these bacteria caused a suppression of the disease by about 60% and a significant increase in tomato plants, and a significant difference with the control was observed.