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采用4室根箱培养系统,探讨了Cu、Zn、Pb、Cd 4种重金属复合污染土壤中,丛枝菌根菌对三叶草生长及吸收、累积重金属的作用,结果表明:重金属Cu 100mg/kg、Zn 600mg/kg、Pb 300mg/kg、Cd 10mg/kg的复合污染对三叶草生物量影响较小,但土壤重金属处理使丛枝菌根菌Glomus intraradices和Glomus caledonium对三叶草的侵染率分别降低53%和56%,菌种G.intraradice的菌丝密度降低73%;接种菌根真菌能明显减少重金属复合污染土壤中三叶草对Cu、Cd和Pb的吸收,并强化根系在限制重金属Pb和Cd向地上部运输中的作用,地上部Pb和Cd含量分别下降24.2%~55.3%和65%~97.9%,使三叶草地上部Cd和Pb含量均低于我国牧草重金属安全含量,提高了三叶草可食部分的质量;不同菌根真菌对三叶草吸收、累积及分配重金属的影响有明显差异,Glomus intraradices对减少三叶草对重金属的吸收及其在地上部可食部分的累积的作用大于Glomus caledonium。丛枝菌根菌对于强化三叶草根系对重金属的固持作用,调节生态系统中重金属的生物循环,减轻重金属对食物链的污染风险方面起着重要作用。
The effects of arbuscular mycorrhizal fungi on the growth, uptake and accumulation of heavy metals in clover were studied using a four-chamber root-box culture system. The results showed that the contents of heavy metals Cu 100 mg / kg, Zn The compound pollution of 600mg / kg, Pb 300mg / kg and Cd 10mg / kg had little effect on clover biomass, but the infection rate of Glomus intraradices and Glomus caledonium by Arbuscular mycorrhizal fungi decreased by 53% 56%. The mycorrhizal density of strain G.intraradice was reduced by 73%. Inoculation of mycorrhizal fungi could significantly reduce the absorption of Cu, Cd and Pb by clover in heavy metal contaminated soils, During the transportation, the content of Pb and Cd in shoots decreased by 24.2% -55.3% and 65% -97.9% respectively, which made the contents of Cd and Pb in shoots lower than the safety of heavy metals in forage grass of our country and increased the quality of clover edible parts . The effects of different mycorrhizal fungi on the absorption, accumulation and distribution of heavy metals in clover were significantly different. The effect of Glomus intraradices on decreasing the absorption of heavy metals and the accumulation of edible parts of aboveground clover was greater than that of Gl omus caledonium. Arbuscular mycorrhizal fungi plays an important role in enhancing the retention of heavy metals in clover roots, regulating the bio-cycles of heavy metals in ecosystems, and reducing the risk of heavy metals contaminating the food chain.