Efficacy of bacillus thuringiensis Cry14 toxin against root knot nematode, meloidogyne javanica

Abstract

Two Bacillus thuringiensis strains including ToIr65 and ToIr67 with nematicidal activity against hatched juveniles and eggs of Meloidogyne javanica were identified by phenotypic, microscopic, 16s rDNA sequencing and nematode cry gene specific PCR. Two forms of bacterial isolates including bacterial suspension (BS) and spore/crystal mixture (SCM) were tested in lab and pot conditions to evaluate their efficacy in M. javanica management. The BS of ToIr65 and ToIr67 showed 70% nematicidal activity in comparison to SCM in vitro. In pot experiments, two forms of ToIr65 significantly (by 51%) decreased number of gall over infested control and also increased growth parameters on tomato plants, but ToIr67 did not. Our results suggested that Bt-ToIr65 could be employed as a biocontrol agent for the management of M. javanica.