Suppression of root‐knot nematodeMeloidogyne incognitaon tomato plants using the nematode trapping fungusArthrobotrys oligosporaFresenius

Abstract

Aim:The aims of the study were to isolate and characterize the nematode trapping fungus, Arthrobotrys oligospora, to investigate the suppressive and predacious activities of the fungus against Meloidogyne incognita and to study the potentiality of A. oligospora in controlling root-knot caused by M. incognita on tomato plants. Methods and Results: Arthrobotrys oligospora (MRDS 300) was isolated from sandy soil samples collected from Al-Beheira, Egypt. In vitro experiments revealed a high efficiency of the fungus in capturing and suppressing M. incognita second juveniles (J 2 ). Microscopic observations showed that the fungus develops adhesive traps consisting of loops of hyphae. Moreover, an in vitro experiment showed that the culture filtrate of A. oligospora had a high toxic effect on the nematode. Pot experiments carried out in two seasons (2018-2019) showed that A. oligospora significantly suppressed root knot on tomato plants caused by M. incognita. The number of females, galls and nematodes in different developing stages were reduced significantly. The treatment with A. oligospora had a prominent effect on enhancing plant growth. Conclusion: Arthrobotrys oligospora had significant suppressive and predacious effects against root-knot nematode, M. incognita. The fungus developed different forms of trapping devices in addition to secreting toxic metabolites to M. incognita. The fungus had a plant-growth promoting effect. Significance and Impact of the Study: Arthrobotrys oligospora (MRDS 300) is a potential biological control agent that can be utilized in controlling the rootknot diseases caused by M. incognita.

Fungal Endophytes and Their Role in Agricultural Plant Protection against Pests and Pathogens

“…Meanwhile, known nematode parasites Arthrobotrys iridis , Metacordyceps chlamydosporia and Hirsutella rhossiliensis , thought to originate in the soil, have been found occurring as plant root endophytes [ 111 ]. These fungi are best known for switching from a saprophytic to a parasitic lifestyle when exposed to nematodes [ 111 , 138 ]. Hyphal structures such as loops and nets, and paralyzing secretions, are used to trap nematodes before hyphae penetrate the cuticle and colonize the body [ 138 , 139 ].…”

“…These fungi are best known for switching from a saprophytic to a parasitic lifestyle when exposed to nematodes [ 111 , 138 ]. Hyphal structures such as loops and nets, and paralyzing secretions, are used to trap nematodes before hyphae penetrate the cuticle and colonize the body [ 138 , 139 ]. Metacordyceps chlamydosporia produces an alkaline serine protease, which digests the outer membrane of nematode eggs, allowing for hyphal penetration and infection of the eggs of both Meloidogyne and Heterodera species [ 111 , 140 ].…”

Mechanism of Antagonistic Bioagents in Controlling Root-Knot Nematodes (Meloidogyne sp.): A Review

“…produces hyphae with sticky features that catch and feed on nematodes as a nematophagous fungus [112,113]. When used before planting tomato seedlings, Arthrobotrys dactyloides reduced the quantity of M. incognita [56,114]. Meloidogyne sp.…”

Natural compounds derived from Brassicaceae plants as an alternative to synthetic fungicides and their influence on soil fungus diversity

“…54 Representatives of the genus Arthrobotrys, such as A. irregularis, trap the juveniles of nematodes before penetration into the roots and can therefore be applied for biocontrol purposes. 55 Diversisporales encompass arbuscular mycorrhizal fungi (AMF) that improve plant growth under stressful conditions by mediating a series of complex communication events between the plant and the fungus leading to enhanced photosynthetic rate and other gas exchange-related traits, 56 as well as increased water uptake. Myrmecridium, Lasiosphaeris, Humicola, and Lophiotrema represent saprobic fungi whose role in the soil environment has not been fully recognized yet.…”