Nematicidal Activity of J211 Against on Tobacco.

Root-knot nematode () is the most widespread nematode affecting Solanaceae crops. Due to the lack of effective measures to control this nematode, its management can be achieved, using biocontrol agents. This study investigated efficacy of the antagonistic bacterial strain J211 isolated from tobacco rhizosphere soil against , and further assessed its role in controlling nematodes, both in pot and field trials. Phylogenetic analysis of the 16S rRNA gene sequence of strain J211 assigned to . Culture filtrates J211 exhibited anematicidal activity against the second-stage juveniles (J2s) of , with a 96.6% mortality after 24 h exposure. Inoculation of J211 in tobacco roots significantly reduced the root galling caused by , both in pot and field trials. Meanwhile, plant growth-promoting (PGP) traits results showed that J211 had outstanding IAA-producing activity, and the IAA production reached 66.60 mg L. In the field study, J211 also promoted tobacco growth and increase flue-cured tobacco yield by 8.7-24.3%. Overall, J211 as a high-yielding IAA nematicidal strain effectively controlled and improved tobacco yield making it a promising alternative bionematocide.