Laboratoire Insulaire du Vivant et de l'Environnement (LIVE), Université de la Nouvelle-Calédonie, BP R4-98851 Nouméa Cedex, Nouvelle-Calédonie, France,
Mycorrhiza. 2013 Oct;23(7):585-95. doi: 10.1007/s00572-013-0499-6. Epub 2013 Apr 16.
In order to improve knowledge about the role of arbuscular mycorrhizal fungi (AMF) in the tolerance to heavy metals in ultramafic soils, the present study investigated the influence of two Glomus etunicatum isolates from New Caledonian ultramafic maquis (shrubland), on nickel tolerance of a model plant species Sorghum vulgare, and of two ultramafic endemic plant species, Alphitonia neocaledonica and Cloezia artensis. In a first step, plants were grown in a greenhouse, on sand with defined concentrations of Ni, to appreciate the effects of the two isolates on the alleviation of Ni toxicity in controlled conditions. In a second step, the influence of the AMF on A. neocaledonica and C. artensis plants grown in a New Caledonian ultramafic soil rich in extractable nickel was investigated. Ni reduced mycorrhizal colonization and sporulation of the fungal isolates, but the symbionts increased plant growth and adaptation of endemic plant species to ultramafic conditions. One of the two G. etunicatum isolates showed a stronger positive effect on plant biomass and phosphorus uptake, and a greater reduction in toxicity symptoms and Ni concentration in roots and shoots. The symbionts seemed to act as a barrier to the absorption of Ni by the plant and reduced root-to-shoot Ni translocation. Results indicate the potential of selected native AMF isolates from ultramafic areas for ecological restoration of such degraded ecosystems.
为了提高对丛枝菌根真菌（AMF）在超镁铁质土壤中耐受重金属作用的认识，本研究调查了来自新喀里多尼亚超镁铁质灌丛（灌木林）的两种球囊霉属（Glomus）内生真菌对模式植物高粱（Sorghum vulgare）和两种超镁铁质特有植物 Alphitonia neocaledonica 和 Cloezia artensis 耐镍性的影响。在第一步中，植物在温室中生长在含有确定镍浓度的沙地上，以评估两种内生真菌对控制条件下减轻镍毒性的影响。在第二步中，研究了 AMF 对在富含可提取镍的新喀里多尼亚超镁铁质土壤中生长的 A. neocaledonica 和 C. artensis 植物的影响。镍降低了真菌内生真菌的菌根定殖和孢子形成，但共生体增加了植物生长和特有植物对超镁铁质条件的适应。两种球囊霉属内生真菌中的一种对植物生物量和磷吸收表现出更强的正向作用，对毒性症状和根和地上部镍浓度的降低作用更大。共生体似乎起到了阻止植物吸收镍的屏障作用，并减少了根到茎的镍转运。研究结果表明，从超镁铁质地区选择的本地 AMF 内生真菌对这种退化生态系统的生态恢复具有潜力。
