Arbuscular mycorrhizal fungi affect both penetration and further life stage development of root-knot nematodes in tomato

Abstract

The root-knot nematode Meloidogyne incognita poses a worldwide threat to agriculture, with an increasing demand for alternative control options since most common nematicides are being withdrawn due to environmental concerns. The biocontrol potential of arbuscular mycorrhizal fungi (AMF) against plant-parasitic nematodes has been demonstrated, but the modes of action remain to be unraveled. In this study, M. incognita penetration of second-stage juveniles at 4, 8 and 12 days after inoculation was compared in tomato roots (Solanum lycopersicum cv. Marmande) pre-colonized or not by the AMF Glomus mosseae. Further life stage development of the juveniles was also observed in both control and mycorrhizal roots at 12 days, 3 weeks and 4 weeks after inoculation by means of acid fuchsin staining. Penetration was significantly lower in mycorrhizal roots, with a reduction up to 32%. Significantly lower numbers of third- and fourth-stage juveniles and females accumulated in mycorrhizal roots, at a slower rate than in control roots. The results show for the first time that G. mosseae continuously suppresses root-knot nematodes throughout their entire early infection phase of root penetration and subsequent life stage development.

Responses of Guava Plants to Inoculation with Arbuscular Mycorrhizal Fungi in Soil Infested with Meloidogyne enterolobii

“…The reduction in penetration may also be due to changes in cell wall composition of the roots (Hol and Cook, 2005), as well as by the activation of plant defense mechanisms stimulated by the AMF (Azcón-Aguilar and Barea, 1996). Vos et al (2011) observed less juveniles penetration in mycorrhizal roots of the Solanum lycopersicum L. cv. Marmande.…”

An integrated functional approach to dissect systemic responses in maize to arbuscular mycorrhizal symbiosis

“…Recent studies have indicated the impact of AMS on plant resistance via mycorrhiza-induced resistance (MIR). Accordingly, various mycorrhizal plants show an increased ability to fight soil-borne pathogens and insects (Pozo et al 2010;Vos et al 2012). In contrast, the influence of AMS on systemic tissues is more variable.…”

Use of the arbuscular mycorrhizal fungus Glomus intraradices as biological control agent of the nematode Nacobbus aberrans parasitizing tomato

“…Plant-parasitic nematodes have been traditionally managed with nematicides (Vos et al 2012). Most of the chemical products used do not comply with current environmental regulations and soon they might be replaced with other management strategies of lower environmental impact (Harrier and Watson 2004).…”

“…Although there were no differences in the number of eggs produced by N. aberrans among treatments, a significant reduction (69%) in the RF of the nematode at T0 was observed. A decrease in RF of different plantparasitic nematodes was detected in the presence of several AMF species (including G. intraradices) (Pinochet et al 1998;Elsen et al 2002;Talavera et al 2002;Castillo et al 2006;Lax et al 2011;Vos et al 2012). A reduction was observed in the final population of Pratylenchus vulnus Allen and Jensen in the roots of peach (Prunus persica L.) colonized by G. mosseae.…”