粗皮侧耳生物学特性及其与杀线虫毒力的关系

 本文报道粗皮侧耳(Pleurotus ostreatus)的生物学特性,尤其是生物学特性与杀线虫毒力的关系。该菌的野生型、驯化型、单孢分离株及孢子分离株的菌丝均能迅速杀死线虫。在固体培养条件下,成熟菌丝产生丰富的毒素球,幼嫩菌丝不产生毒素球;该菌在多种固体培养基,甚至营养缺乏的水琼脂上也生长良好;生长的最适条件为24~28℃、pH5.6~8.0、固体或液体遮光培养。尽管营养、温度、pH及光照等对菌丝生长均有显著影响,但并不影响其对线虫的毒力,各菌株间毒力无差异,线虫与菌丝接触48h,死亡率均达90%以上;液体培养滤液能杀死线虫,但其对线虫毒力的强弱却与菌株、滤液浓度及培养时间等有关。首次以实验证明了该菌在液体培养条件下可产生杀线虫毒素。

RELATIONSHIP BETWEEN BIOLOGICAL CHARACTERISTICS AND NEMATICIDAL TOXICITY OF Pleurotus ostreatus

Pleurotus ostreatus Kummer (Basidiomycotina:Agaricales)is a promising nematophagous fungus in the biocontrol of plant-parasitic nematodes.This paper reported the biological characteristics,especially the relationship between them and the nematicidal toxicity of P.ostreatus.The hyphae of different strains of P.ostreatus, from cultivated mushroom,single basidiospore,anastomosing hyphae and wild strain from nematodes infected by P.ostreatus, could destroy nematodes very quickly.The mature hyphae produced tiny droplets of toxin from minute secretary cell on solid media.The droplets of toxin were not present on the young hyphae at the edge of a colony.When nematodes touched the hyphae,they became inactivated very quickly and were subsequently colonized and digested by this fungus.The toxicity to destroy nematodes of different strains was similar.
The maximum growth of the fungi occurred at temperature 24-28℃,pH5.6-8.0,and solid or liquid culture in the dark.Although media,temperature,light and pH value had some effects on hyphal growth, they did not affect the nematicidal toxicity.The destroying rates of nematodes treated by the hyphae were 98%-100% within 48 hours.The culture filtrate of hyphae contained nematicidal toxin and could kill nematodes.However,the nematicidal activities wererelated to strains,concentrations and the culture time of hyphae under liquid culture.