多环芳烃污染对丛枝菌根真菌生物学性状的影响

Effects of Polycyclic Aromatic Hydrocarbons on Biological Characteristics of Arbuscular Mycorrhizal Fungi

通过温室盆栽试验,以侵染率、丛枝率、菌根长度、菌丝密度、泡囊数、孢子数等为指标,系统地研究了多环芳烃(PAHs)污染对丛枝菌根真菌(AMF)生物学性状的影响。供试AMF为幼套球囊霉Glomus etunicatum(Ge)、摩西球囊霉Glomus mosseae(Gm)和层状球囊霉Glomus lamellosum(Gla),供试PAHs为菲和芘。土壤中菲和芘含量分别为41.87、42.80 mg·kg-1时,接种AMF后35~65 d,AMF各项生物学指标随培养时间延长均呈增大的趋势;65~75 d,由于部分丛枝衰老和消解导致AMF侵染率、丛枝率和菌根长度下降。接种AMF后65 d,与无污染对照相比,供试PAHs污染胁迫下AMF侵染率、丛枝率、菌根长度变小,且随PAHs污染强度增大这3项AMF指标趋小;AMF菌丝密度和孢子数变化与PAHs污染强度密切相关,供试高浓度PAHs污染下AMF菌丝延伸和孢子形成受到抑制,导致菌丝密度和孢子数减小,低浓度PAHs污染下该2项指标增大;供试PAHs污染胁迫下AMF泡囊数未发生显著变化。

The effects of polycyclic aromatic hydrocarbons(PAHs)on mycorrhizal colonization rate,arbuscule rate,mycorrhizal root length,hyphal density,vesicule and spore numbers of arbuscular mycorrhizal fungi(AMF),were investigated in a pot experiment.Phenanthrene and pyrene were selected to represent PAHs.AMF were Glomus etunicatum(Ge),Glomus mosseae(Gm),and Glomus lamellosum(Gla).At41.87 and 42.80 mg·kg-1of phenanthrene and pyrene concentrations in soil,respectively,all examined parameters of AMF increased with incubation time during 35~65 d after inoculation.However,the mycorrhizal colonization rate,arbuscule rate,and mycorrhizal root length of AMF decreased 65~75 d after inoculation,due to death and degradation of arbuscules.The mycorrhizal colonization rate,arbuscule rate,and mycorrhizal root length of AMF decreased with increasing PAHs concentrations in soils.The hyphal density and spore production of AMF reduced at high PAHs concentrations,whereas promoted at low concentrations.The vesicule number of AMF changed little under the stress of PAHs at the tested concentrations.