INFLUENCE OF DIFFERENT N FORMS ON SPORE GERMINATION AND HYPHAL GROWTH OF AM FUNGUS
不同氮形态对AM真菌孢子萌发和菌丝生长的影响

Influence of different N forms on spore germination and hyphal growth of AM fungus, Gigaspora margarita, were investigated on Long-Ashton medium. Results indicated that spore germination was fast at early stage and slow at late stage on NO3--N and NH4 -NO3--N mediums, but just the reverse on NH4 -N medium. No difference was detected among spore germination rates on three mediums at finial stage, all reaching about 50%. Significant difference was observed among the hyphal growths on three mediums. Extending rate and length of germ hyphae were higher on NO3--N and NH4 -NO3--N mediums than on NH4 -N medium. This experiment demonstrated that NH4 -N didnt reduce AM fungal spore germination, but inhibited the hyphal growth, as compared with NO3--N and NH4 -NO3--N.