Biocontrol of Root-Knot Nematode Meloidogyne incognita by Chitinolytic Trichoderma spp.

Abstract

The inhibitory potential of chitinolytic Trichoderma spp. was assayed against Meloidogyne incognita in vitro and in vivo. Sixteen Trichoderma isolates were assayed for chitinase activity using basal solid medium supplemented with colloidal chitin. Isolates recorded high chitinolytic activity were identified morphologically as Trichoderma asperelloides, T. hamatum, T. harzianum and T. viride. The four species were quantitatively assayed for total and specific chitinase activity. T. asperelloides showed maximum chitinase activity (1.736 U/mL). In vitro studies revealed that egg hatching and second juveniles vitality of root-knot nematodes were significantly inhibited by chitinase-containing growth culture of the four selected chitinolytic Trichoderma species. However, the reduction effect was directly correlated with the concentration of fungal growth suspension. Under greenhouse conditions, three sequentially treatments of soil with homogenized culture suspension were studied. Trichoderma species significantly reduced the final nematode population by 97.81% and root galling by 92.81%. Moreover, all tested Trichoderma species obviously promoted tomato growth compared to untreated control. Significant positive correlation between the biocontrol efficacy of Trichoderma species against root-knot nematodes and their chitinolytic activity was confirmed. The most potential chitinolytic species, T. asperelloides, also recorded the highest biocontrol activity against M. incognita.

Potentiality of Trichoderma Species against Fusarium oxysporum f. sp. cucumerinum and Meloidogyne javanica Disease Complex in Cucumber Plants

“…In our study, T. hamatum exhibited the highest rate of enzyme activity, whether with nematode or fungus separately. According to Sayed et al (2019), T. asperelloides and T. hamatum have strong chitinase activity. Elad and Henis (1982) and Haran et al (1996) established that the biological control of the Trichoderma genus against plant pests and diseases is mostly due to the release of hydrolytic enzymes such as -1, 3-glucanase, chitinase, protease, and lipase, which are responsible for antagonism.…”

Nematicidal Effect of Three Trichoderma spp. on the Suitability of Tomato Plants for Meloidogyne incognita Reproduction

“…Agronematol., Vol. 21, No.2 (2022) Noronha and Ulhoa, 2000), chitinase from Trichoderma species (Sayed et al, 2019;Spiegel et al, 2007) and proteinase from T. atroviride (Spiegel et al, 2007) able to degrade cell wall for fungi. In concerning of egg hatching and J2 vitality, chitinasecontaining growth culture was associated with the concentration of fungal growth suspension as a renewable source of chitinase (Sayed et al, 2019).…”

“…21, No.2 (2022) Noronha and Ulhoa, 2000), chitinase from Trichoderma species (Sayed et al, 2019;Spiegel et al, 2007) and proteinase from T. atroviride (Spiegel et al, 2007) able to degrade cell wall for fungi. In concerning of egg hatching and J2 vitality, chitinasecontaining growth culture was associated with the concentration of fungal growth suspension as a renewable source of chitinase (Sayed et al, 2019). Chitin, an insoluble linear b-1,4-linked polymer of N-acetylglucosamine, is a common constituent of a wide range of organisms, including fungi, insects, and crustaceans, and it occurs also in nematode eggs (Flach et al, 1992).…”

“…A significant positive correlation was found between Trichoderma spp. as biocontrol agent against RKNs and their chitinolytic activity, where T. asperelloides, was the most promising chitinolytic species, demonstrating the greatest activity against M. incognita (Sayed et al, 2019).A direct effect of plant growth and nematode population density reduction extended to 90 days after inoculation with no significant differences between treatments (Devi and Richa Sharma, 2002).…”

Selección y caracterización de microorganismos con capacidad antifúngica y fertilizante aislados de la rizosfera de plantas de yerba mate de la provincia de Misiones para su aplicación como promotores del crecimiento vegetal

“…Con respecto a T. hamatum, los resultados mostraron que es capaz de producir una variedad de enzimas, pero en bibliografía son escasos reportes sobre estudios de la capacidad de producción enzimática de esta especie en relación a su acción como PGPM (Sayed et al, 2019), al igual para la especie T. strigosellum.…”