小叶白蜡接种外生菌根真菌对土壤石油烃的降解效果

采用盆栽实验研究了小叶白蜡(Fraxinus sogdiana)接种4种外生菌根真菌(E1-毛边滑锈伞(Hebeloma mesophaeusm)、E2-劣味乳菇(Lactarius insulsns)、E3-松塔牛肝菌(Stro-bilomyces floccopus)和E4-丝膜菌(Cortinarius russus)对沈抚灌区土壤石油烃的降解效果。结果表明:在白蜡不同组合双接种及混合接种中,以混合接种对土壤石油烃的降解效果最好,降解率比对照提高23.6%;其次为双接种中的E1E3和E2E4组合,降解率分别比对照提高21.0%和12.7%。接种外生菌根真菌可促进白蜡生长,尤其可明显提高其根生物量,增加侧根数,接种E1E3、E2E4和混合菌使白蜡侧根数分别增加了100%、67%和81%。相关分析表明,石油烃降解率与白蜡的侧根数呈显著相关,可能是其降解率提高的主要原因。

Degradation effect of ectomycorrhizal fungi-inoculated Fraxinus sogdiana on petroleum hydrocarbon in soil

With pot experiment, this paper studied the degradation effect of Fraxinus sogdiana inoculated with ectomycorrhizal fungi E1-Hebeloma mesophaeusm, E2-Lactarius insulsns, E3-Strobilomyces floccopus, and E4-Cortinarius russus on the petroleum hydrocarbon in soil of Shenfu sewage irrigation area. The results showed that the degradation rate of soil petroleum hydrocarbon was enhanced by 23.6% when the F. sogdiana was inoculated with the 4 species of ectomycorrhizal fungi together, and by 21.0% and 12.7% when inoculated with E1E3, and E2E4, respectively, compared with the control. Inoculation with ectomycorrhizal fungi could improve the growth of F. sogdiana, and especially, increase its root biomass and the number of side-roots. When inoculated with E1E3, E2E4, and four associated ectomycorrhizal fungi, the number of side-roots increased by 100%, 67%, and 81%, respectively, and a significant positive correlation was observed between the degradation rate of soil petroleum hydrocarbon and the number of side-roots, suggesting that the increase of side-root number was the main reason for the increasing degradation rate of petroleum hydrocarbon in soil.