改良铅锌矿渣对栾树幼苗铅锌富集与耐性机制

植物修复是尾矿区恢复的一项生态技术，添加基质改良剂可以减轻重金属对植物的胁迫，提高修复效率.以木本植物栾树（Koelreuteria paniculata）作为供试植物，分别在100%尾矿（S）、90%的尾矿+5%蘑菇渣（SMC）+5% CaCO₃（MS）和天然红壤（RS）中进行盆栽试验.探究不同处理下栾树耐受Pb和Zn的生长富集效应、微观特征变化和基质中微生物多样性变化.结果表明，改良剂的添加相比于尾矿可以显著改善尾矿基质的理化结构，显著提升栾树的生物量、株高和叶绿素含量等相关生理指标，增加栾树中积累的重金属含量.处理组MS相较于对照组RS总根长增长达到69.3%，而对照组RS平均根径相较于对照组S下降118.7%.处理组MS与对照组S相比，Pb和Zn残渣态增加266.67%，弱酸可提取态和氧化物结合态显著降低，重金属对于植株迁移活性减弱.同时，多数重金属被栾树截留在根部，其根系构型的变化表明其在面对高浓度的Pb胁迫时具有较强的适应性.透射电镜（TEM）分析表明，对照组S中较高浓度的重金属含量会破坏细胞壁结构，对植物细胞造成毒害.改良剂的添加有效缓解了重金属胁迫对栾树各组织的影响，影响微生物群落的结构，显著提高微生物丰富度和多样性，增强栾树对重金属的适应性和植物修复能力.

Mechanism of Lead-zinc Enrichment and Resistance of Spent Mushroom Compost to Lead-Zinc Slag in Koelreuteria paniculata

Phytoremediation is an ecological technique for tailing area restoration; adding substrate modifiers can reduce the stress of heavy metals on plants and enhance the restoration efficiency. The woody plant Koelreuteria paniculata was used as a test plant and potted in 100% tailings (S), 90% tailings+5% mushroom residue (SMC)+5% CaCO₃ (MS), and natural red soil (RS). The effects of physiological responses and tolerance enrichment effects on Pb and Zn tolerance in K. paniculata under different treatments were investigated to compare the growth morphology, microscopic morphological changes, and microbial diversity changes in each substrate of K. paniculata seedlings. The results showed that compared with the control group S, the MS treatment group could significantly improve the structure and fertility of the tailing substrates; significantly enhance the relevant physiological indicators such as biomass, plant height, and chlorophyll content of K. paniculate; and increase the accumulated heavy metal content in K. paniculata. In the treatment group, the overall physiological indexes of MS compared to RS biomass and plant height were promoted, and the total root length increased up to 69.3%, whereas the average root diameter of RS in the treatment group decreased 118.7% compared to that in the control group S. The MS treatment group showed a 266.67% increase in Pb and Zn residue state, a significant decrease in the weak acid extractable state and oxide-bound state compared to that in the control group S. The heavy metals were less active for plant migration. Furthermore, most of the heavy metals were trapped in the roots of K. paniculata, and the changes in its root conformation indicated its strong adaptability in the face of high Pb stress. Transmission electron microscopy (TEM) analysis showed that the higher concentration of heavy metals in the S control damaged the cell wall structure and caused toxic effects on plant cells. The addition of the modifier effectively alleviated the effects of heavy metal stress on various tissues of K. paniculata, affected the structure of microbial communities, significantly increased microbial richness and diversity, and enhanced the adaptability of K. paniculata to heavy metals and phytoremediation ability.