Abstract: In order to ascertain the harmfulness of nematode (Trilabiatus spp.) in mushroom production, the effect of nematode on mushroom mycelium growth was carried out in this study. The investigation was given on nematode genera and their quantity in mushroom growing beds and substances (straw and cow dung substrate) from serious mushroom mycelium damaged areas in Qinzhou region of Tianshui City, Gansu Province (in mid and late August, 2006) and in Cangnan County of Wenzhou City, Zhejiang Province (in beginning of August, 2009 and February, 2010). The methods of purification of Trilabiatus spp. and their inoculation on slant medium of wood ear mushroom (Auricularia auricular) and button mushroom (Agaricus bisporus) were used for the study. The number of Trilabiatus spp. was quite large in the substrate on which the mycelium was damaged seriously. The nematode could propagate in a large number on the two kinds of mushroom mycelium. After inoculated for 2 or 3 weeks, the nematode quantity increased 365 and 208 times, respectively on the mycelium of wood ear mushroomand button mushroom. The symbacteria on the surface of nematode could only accelerate the nematode affecting mycelium growth, but would not damage themselves. The nematodes, Trilabiatus spp. can affect hyphas normal growth, resulting in mycelium of wood ear mushroom and button mushroom becoming dark yellow, black brown and further premature withered．

Key words: nematode, Trilabiatus spp., wood ear mushroom, button mushroom, mycelium