Abstract
Meloidogyne is the most damaging plant parasitic nematode genus affecting vegetable crops worldwide. The induction of plant defense mechanisms against Meloidogyne in tomato by some Trichoderma spp. strains has been proven in pot experiments, but there is no information for tomato bearing the Mi-1.2 resistance gene or for other important fruiting vegetable crops. Moreover, Trichoderma is mostly applied for managing fungal plant pathogens, but there is little information on its effect on nematode-antagonistic fungi naturally occurring in soils. Thus, several experiments were conducted to determine (i) the ability of two commercial formulates of Trichoderma asperellum (T34) and Trichoderma harzianum (T22) to induce systemic resistance in tomato and cucumber against an avirulent Meloidogyne incognita population in split-root experiments; (ii) the effect of combining T34 with tomato carrying the Mi-1.2 resistance gene to an avirulent M. incognita population in sterilized soil; and (iii) the effect of combining T34 with tomato carrying the Mi-1.2 resistance gene to a virulent M. incognita population in two suppressive soils in which Pochonia chlamydosporia is naturally present, and the effect of T34 on the level of P. chlamydosporia egg parasitism. Both Trichoderma formulates induced resistance to M. incognita in tomato but not in cucumber. In tomato, the number of egg masses and eggs per plant were reduced by 71 and 54% by T34, respectively. T22 reduced 48% of the number of eggs per plant but not the number of egg masses. T34 reduced the number of eggs per plant of the virulent M. incognita population in both resistant and susceptible tomato cultivars irrespective of the suppressive soil, and its effect was additive with the Mi-1.2 resistance gene. The percentage of fungal egg parasitism by P. chlamydosporia was not affected by the isolate T34 of T. asperellum.
Highlights
The root-knot nematodes (RKN), Meloidogyne spp., are the most damaging obligate plant-endoparasitic nematode worldwide in a wide range of plant species (Jones et al, 2013)
The effect of combining resistance genes (R-genes) with induced resistance by Trichoderma was more evident against the virulent nematode population than the avirulent one, which was highly suppressed by the Mi-1.2 resistance gene relatively less infection (34%) and reproduction (67%) was recorded in relation to the noninoculated plants
This study proves that the strains T34 of T. asperellum and T22 of T. harzianum induce resistance against M. incognita in tomato but not in cucumber, at least under our experimental conditions
Summary
The root-knot nematodes (RKN), Meloidogyne spp., are the most damaging obligate plant-endoparasitic nematode worldwide in a wide range of plant species (Jones et al, 2013). Maximum yield losses reported for fruiting solanaceous and cucurbit crops, the most cultivated worldwide, range from 30 to 100% (Giné et al, 2014, 2017; López-Gómez et al, 2014; Seid et al, 2015; Giné and Sorribas, 2017; Hallman and Meressa, 2018). Despite that several methods for control are available (Nyczepir and Thomas, 2009), most producers rely on the use of chemical nematicides (Djian-Caporalino, 2012; Talavera et al, 2012). Due to the risks and impacts on human health and the environment, its use must be reduced in favor of alternative methods according to legislative regulations, such as the European Directive 2009/128/EC. Sustainable and safe alternatives are required, such as plant resistance and biological control (Hallmann et al, 2009; Williamson and Roberts, 2009)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
