Establishment and Meloidogyne-capture of an adhesive hyphaeforming isolate of the fungus Arthrobotrys oligospora in soil

Abstract

In situ observations of an isolate of Arthrobotyrs oligospora (CBS 289.82) in sterilized and untreated soil revealed attachment of second-stage juveniles of the root-knot nematode Meloidogyne hapla to hyphae, development of rings around the nematode body and nematode colonization by trophic hyphae. Abundant growth of rings from infected nematodes was never observed. Establishment and nematode capture by this isolate was compared with those of several other fungi from the Dactylaria-complex in a simple soil microcosm system. Application of hyphal fragments of A. oligospora (CBS 289.82), about 30 mm g −1 oven-dry soil, resulted in hyphal lengths of 100–170 m g −1 oven-dry soil, reduction of 90% of living juveniles of M. hapla within 1 day and extermination of the nematodes after 10 days. Arthrobotrys oligospora (CBS 289.82) performed far better than any of the other fungi. Establishment in non-sterilized soil was not as good, but still total hyphal length of about 10 g −1 oven-dry soil resulted in 70% reduction of living nematodes at Day 10. At 13°C results were similar to those at 20°C. The results support the conclusion that adhesive hyphae-forming fungi may be useful for the control of nematodes in soil.