为明确丛枝菌根（AM）真菌对促进绿化苗木镉（Cd）吸收的影响，通过盆栽试验比较接种不同AM真菌对12种绿化苗木Cd吸收的差异，并进一步分析接种对金叶六道木根际微生物数量和AM真菌群落结构的影响。结果表明，12种绿化苗木，加Cd处理6个月后，其叶片浓度的变化范围为0.25～2.59 mg·kg-1。接种AM真菌处理组的叶片Cd含量均高于不接菌处理组。相比未接种，接种AM2摩西球囊霉（BGCAM00164）后金叶六道木叶片中Cd含量增加147.9%，故选择金叶六道木进行后续研究。接种AM212个月后，金叶六道木的根、枝、叶Cd浓度分别为164.7、22.86和10.57 mg·kg-1，为不接菌处理的2.64倍、2.06倍和1.76倍，全株总Cd含量达5 078 μg·株-1，显著高于不接菌对照（1 745 μg·株-1）。相比不接菌对照，接种AM2后降低了转移系数，将其更多吸收的Cd固定在根内，从而减少对植株的损害。接种AM真菌增加了AM真菌PLFA生物量，但降低了根际土壤微生物细菌和真菌PLFA生物量。所有样本中丰度较高的AM真菌为球囊霉科（Glomus）、类球囊霉科（Paraglomus）和原囊霉科（Archaeospora）。球囊霉科占总AM真菌的55%以上，是金叶六道木根际的主要优势种群。接种AM2后球囊霉丰度显著增加，由对照的61.8%上升至77.4%，但AM真菌的整体多样性和丰富度则表现为下降。接种AM1后类球囊霉科丰度显著增加，由对照的13.1%上升至17.8%，但球囊霉丰度无显著变化。主成分分析结果表明Cd和AM真菌接种可以改变金叶六道木根际AM真菌群落结构。总体而言，接种AM真菌（摩西球囊霉）能提高金叶六道木对土壤重金属Cd污染的修复效率，其联合修复技术可扩展Cd污染土壤植物修复的应用范围。
[Objective] As a pollutant element generated from industrial and agricultural activities, cadmium (Cd) has become an intensifying environmental problem throughout the world. In order to investigate effects of arbuscular mycorrhizal fungi (AMF) on green seedling Cd uptake, a pot experiment was conducted.[Method] A total of twelve species of green seedlings were planted in the Cd-contaminated pots, separately, with or without AMF inoculation. Particular attention was given to the seedlings of A. grandiflora. Effects of inoculation with AMF on population of the microbes and AMF community structure in the rhizosphere of A. grandiflora were analyzed using the PLFA and Hiseq techniques.[Result] After six months, the twelve species of seedlings ranged from 0.25 to 2.59 mg·kg-1 in leaf Cd concentration, and exhibited an order, excluding Ligustrum japonicum ‘Howardii’ and Eurya emarginata (Thunb.) Makino, of Camellia sasanqua Thunb. < Osmanthus fragrans(Thunb.)Lour < Ligustrum quihoui < Ligustrum sinense ‘Variegatum’ < Elaeagnus pungens var. varlegata Rehd. < Distylium buxifolium < Weigela florida cv. Red Prince < Photinia×fraseri Dress < Abelia grandiflora ‘Francis Mason’ < Weigela florida cv. Variegata. The group inoculated with AMF was obviously higher than their respective ones in the control group without AMF inoculation in leaf Cd concentration. Compared with the control of the same plant, A. grandiflora inoculated with AM2 (Glomus mosseae, BGCAM00164) was 147.85% higher in leaf Cd concentration, so A. grandiflora was designated for investigation in ongoing researches. Twelve months after inoculation with AM2, the plant had Cd concentration in its root, stem and leaf increased up to 164.7, 22.86 and 10.57 mg·kg-1, or 2.64, 2.06 and 1.76 times as high as that in the control, making up a total of 5 078 μg·plant-1, higher than that of the control, which is only 1 745 μg·plant-1. Apparently AM2 reduced the translocation factor and fixed more Cd in the root, thus mitigating Cd damage to the plant. The inoculation of AMF increased PLFA biomass of the AMF, but reduced that of the bacteria and fungi in rhizosphere soil. Glomus, Paraglomus and Archaeospora were the phyla of fungi relatively high in richness in all the samples. Glomus accounted for 55% of the total fungal population, and hence the chief dominant group in the rhizosphere of A.grandiflora. In treatments AM2, Glomus increased significantly from 61.8% to 77.4%, while the AMF community, as a whole, decreased in diversity and richness in the rhizosphere soil, whereas in treatments AM1, Paraglomus increased from 13.1% to 17.8%, but Glomus did not change much. Principal component analysis shows that the AMF community was altered by Cd contamination and AMF inoculation in the rhizosphere of A.grandiflora.[Conclusion] Generally speaking, inoculation with Glomus mosseae may improve the efficiency of A. grandiflora phytoremedying Cd contaminated soils. This type of combined remediation technology can expand the scope of phytoremediation of Cd contaminated soils.
刘琛,郭彬,林义成,傅庆林,李凝玉.丛枝菌根真菌对金叶六道木镉吸收及根际真菌群落结构的影响[J].土壤学报,2021,58(2):495-504. DOI:10.11766/trxb201911090379 LIU Chen, GUO Bin, LIN Yichen, FU Qinglin, LI Ningyu. Impacts of Arbuscular Mycorrhizal Fungus Enhancing Abelia grandiflora ‘Francis Mason’ Cd Uptake on Rhizospheric Fungal Communities[J]. Acta Pedologica Sinica,2021,58(2):495-504.复制