Density-dependence and host-specificity of the nematode-trapping fungus Monacrosporium ellipsosporum

Abstract

SUMMARY The infection rate of Meloidogyne incognita juveniles was reduced by more than 90 O/o following migration through soil infested with the nematode-trapping fungus, Monacrosporium ellipsosporum to tomato roots. M. ellipsosporum reduced the number of juveniles penetrating tomato roots and the number of juveniles remaining in the soil twelve days post-treatment. The number of M. incognita juveniles entering roots decreased with increased M. ellipsosporum inoculum density. M. ellipsosporum sticky knob traps were tested for adhesion specificity to fiiteen different species of nematodes. Acrobeloides sp., Aphelenchoides sp., Aphelenchus avenae, Criconemella xenoplax, Meloidogyne incognita, Pratylenchus scribneri, Seinura oxuris, and Tylenchulus semipenetrans, adhered to the sticky knobs while Longidorus aji-icanus, Mesodo ylaimus sp., Paratrichodorus minor, Xiphinema anzericanunz, and Diplenteron sp. adults did not. Zotonchus brachyzaimus anly rarely adhered. Fifteen sugars were tested for suppression of adhesion of Panagrellus redivivus to the sticky knobs of M. ellipsosponim. Fucose, D-fructose and lactose suppressed adhesion of P. redivivus to the knobs at 20 mM, but some nematodes adhered even at 200 mM concentrations. Alpha-methyl-D-mannoside, L-sorbose, Darabinose, alpha-D-mellibiose, D (+) trehalose, and sucrose suppressed adhesion of P. redivivus at 200 mM but not at 20 mM Concentrations. N-acetyl-galactosamine and L-xylose did not suppress adhesion at 20 mM or 200 mM concentrations.