不同磷水平下外生菌根真菌对铅的耐性反应

采用液体离体培养的方法，研究了不同磷和铅水平对3个外生菌根真菌生物量、ZC₁菌丝含磷量和含铅量的影响.结果表明，不同水平的磷和铅胁迫下，菌种ZC₁和ZC₂的生物量显著高于菌种GV(Gomphidius viscidus)；低磷时（0.16 mmol·L^-1），3个菌种的生物量随着铅浓度的增加都受到了抑制，在较高的磷水平下(0.81和2.42 mmol·L^-1)，铅浓度的增加显著的抑制了菌种GV的生物量，但对菌种ZC₁和ZC₂的生物量没有显著抑制.GV的菌丝含铅量在各处理水平下都显著高于ZC₁和ZC₂.同一铅水平下，GV的菌丝含磷量在低磷时高于ZC₁和ZC₂，在较高磷浓度时却低于ZC₁和ZC₂；铅浓度的增加降低了菌种ZC₂和GV的菌丝含磷量，但菌种ZC₁的菌丝含磷量没有受到显著的抑制.与无污染地采集的菌种GV相比，污染地采集的菌种ZC₁和ZC₂表现出快速生长、低铅积累以及高磷吸收的特点，显示出较高的抗环境胁迫能力.

Pb-tolerance of ectomycorrhizal fungi from polluted and unpolluted sites under different P levels

By the method of liquid culture, this paper studied the effects of different P and Pb doses on the biomass production of three strains of ectomycorrhizal fungi, and the P and Pb concentrations in their mycelium. The results showed that under the application of P and Pb, the biomass production of strains ZC1 and ZC2, collected from mining area was significantly higher than that of strain GV collected from non-polluted site. At low P level (0.16 mmol x L(-1)), the growth of these three ectomycorrhizal fungi was inhibited by the increasing dose of Pb; while at higher P levels (0.81and 2.42 mmol x L(-1)), increasing dose of Pb inhibited the growth of GV significantly, but had little effects on ZC1 and ZC2. In all treatments, the Pb concentration in GV mycelia was significantly higher than that in the mycelia of ZC1 and ZC2. Under the same dose of Pb, the P concentration in GV mycelia was higher at low P level, but lower at higher P levels than that in ZC1 and ZC2 mycelia. The increase of Pb dose decreased the P concentration in ZC1 and ZC2, mycelia, but had little effect on that in GV mycelia. In comparing with GV, ZC1 and ZC2 had the characteristics of fast growth and low Pb and high P accumulation in their mycelia, indicating that the strains of ecomycorrhizal fungi collected from polluted area had a higher tolerance to environmental stress.