改良锰矿渣中真菌群落对栾树生长及植物修复过程的影响

Fungal community danamics in phytoremediation of manganese slag amended with Koelreuteria paniculata

真菌群落在锰矿渣的植物修复中发挥了重要作用,但作用机制尚不明确.本文以栾树(Koelreuteria Paniculata)为供试植物,以蘑菇渣(SMC)和凹凸棒土(ATP)为改良剂,以广谱真菌抑制剂苯菌灵为灭菌剂.通过比较无植物的锰矿渣(CK)、控制灭菌的无植物改良矿渣(S0:灭菌;S1:不灭菌)和控制灭菌、种植栾树的改良矿渣(P0:灭菌;P1:不灭菌)等5个处理基质的理化性质、重金属赋存状态、真菌多样性差异和植物生长差异,探究控制灭菌、矿渣改良与植物修复间的关联性.结果显示:改良矿渣中总氮、总磷和有机质含量较锰矿渣(CK)分别提升约219%、32%和111%.施加改良剂显著提高了锰矿渣的pH、有效氮、磷、钾以及蔗糖酶和脲酶活性,改善并能够长期维持其肥力和保水性;施加改良剂并种植栾树使得锰矿渣中真菌结构由以子囊菌门(Ascomycota,51.91%)为主的共营养型向以担子菌门(Basidiomycota,67.73%)为主的寡营养型转变,栾树的生长激活并富集了有益真菌,抑制了病原真菌;Mantel检验显示了真菌群落更高的稳定性,VPA分析表明真菌群落主要受重金属含量和土壤肥力的共同影响(39.8%),其次是土壤肥力(31.4%).灭菌处理下,栾树对锰矿渣土壤肥力的稳固作用要明显降低,同时对于重金属的耐受性和解毒能力也明显减弱,这与真菌群落活力的下降和群落结构的改变密切相关.研究表明,真菌群落结构的改善和多样性的提高对于改善土壤质量、促进植物生长和缓解重金属毒性等方面具有重要意义.

Fungal communities play a crucial role in the phytoremediation of manganese slag,but the specific mechanisms remain unclear.In this study,Koelreuteria paniculata was used as the test plant,while spent mushroom compost(SMC)and attapulgite(ATP)were used as amendments.Benomyl,a broad-spectrum fungal inhibitor,was used to control fungal variables in the slag.The study compared the physicochemical properties,heavy metal distribution,fungal diversity differences in substrates,and plant growth among five treatments:manganese slag(CK),sterilized manganese slag(S0:sterilized;S1:non-sterilized),and non-sterilized amended manganese slag with or without K.paniculata(P0:sterilized+plant;P1:non-sterilized+plant).The correlation between soil sterilization,amendments,and phytoremediation process was explored.The results showed that the contents of total nitrogen,total phosphorus,and organic matter in the amended slag increased by approximately 219%,32%,and 111%,respectively,compared to CK.The application of amendments significantly increased pH,available nitrogen,phosphorus,potassium,sucrase,and urease activity of manganese slag,improving and maintaining its fertility and water retention in the long-term.The application of amendments and planting of K.paniculata transformed the fungal community structure of manganese slag from mainly Ascomycota(51.91%)to Basidiomycota(67.73%).This change enriched beneficial fungi that activated plant growth,suppressed pathogenic fungi,and increased the stability of the fungal community,as evidenced by Mantel test.Variance partitioning analysis(VPA)showed that the fungal community was mainly affected by both heavy metal content and soil fertility(39.8%),followed by soil fertility alone(31.4%).Sterilization significantly decrease the stable effect of K.paniculata on soil fertility in manganese slag,and its tolerance to heavy metals and detoxification ability,which was related to a decrease in the vitality of the fungal community and the change in community structure.The study demonstrated that the improvement of fungal community structure and diversity has significant implications for improving soil quality,promoting plant growth,and mitigating heavy metal toxicity.