Endophytic Paenibacillus polymyxa LMG27872 inhibits Meloidogyne incognita parasitism, promoting tomato growth through a dose-dependent effect

Richard Raj Singh, Wim Wesemael

Onderzoeksoutput: Bijdrage aan tijdschriftArtikelpeer review


The root-knot nematode, Meloidogyne incognita, is a major pest in tomato
production. Paenibacillus polymyxa, which is primarily found in soil and
colonizing roots, is considered a successful biocontrol organism against many
pathogens. To evaluate the biocontrol capacity of P. polymyxa LMG27872
against M. incognita in tomato, experiments were conducted both in vitro and
in vivo. A dose-response effect [30, 50, and 100% (108 CFU/mL)] of bacterial
suspensions (BSs) on growth and tomato susceptibility to M. incognita with
soil drenching as a mode of application was first evaluated. The results show
that the biological efficacy of P. polymyxa LMG27872 against M. incognita
parasitism in tomato was dose-dependent. A significantly reduced number of
galls, egg-laying females (ELF), and second-stage juveniles (J2) were observed
in BS-treated plants, in a dose-dependent manner. The effect of P. polymyxa
on tomato growth was also dose-dependent. A high dose of BSs had a
negative effect on growth; however, this negative effect was not observed
when the BS-treated plants were challenged with M. incognita, indicating
tolerance or a defense priming mechanism. In subsequent in vivo experiments,
the direct effect of BSs was evaluated on J2 mortality and egg hatching
of M. incognita. The effect of BS on J2 mortality was observed from 12 to
24 h, whereby M. incognita J2 was significantly inhibited by the BS treatment.
The effect of P. polymyxa on M. incognita egg hatching was also dependent
on the BS dose. The results show a potential of P. polymyxa LMG27872 to
protect plants from nematode parasitism and its implementation in integrated
nematode management suitable for organic productions.
Oorspronkelijke taalEngels
TijdschriftFrontiers in Plant Science
PublicatiestatusGepubliceerd - 14-sep-2022

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