The effect of toxin-producing Rhizobium strains, on larvae of Sitona flavescens feeding on legume roots and nodules

摘要: Larvae of the weevil Sitona spp. specifically eat root nodules formed on legume plants by soil bacterium Rhizobium. This can adversely affect nitrogen fixing activity in and lead to decreases yield. Transgenic rhizobia were used a novel approach biological control Sitona. Two transcriptional fusions made which coding sequence insecticidal crystal protein gene (cryIIIA) from Bacillus thuringiensis subsp. tenebrionis was fused either promoter rhizosphere enhanced rhiA R. leguminosarum biovar viciae, or nodule specific nifH bv. trifolii. The two chimeric genes transferred viciae trifolii, respectively. Bioassay systems allowed easy inspection plant test transgenic strains for their ability protect host damage larvae flavescens. In both white clover pea nodulated slightly smaller proportion damaged compared wild type plants. some bioassays this accompanied increased nitrogenase activity, but it not reflected growth, similar treatments. These results suggest that toxin with much higher toxicity against is necessary biocontrol succeed.