Vivas A, Vörös I, Biró B, Campos E, Barea J M, Azcón R
Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Profesor Albareda 1, 18008 Granada, Spain.
Environ Pollut. 2003;126(2):179-89. doi: 10.1016/s0269-7491(03)00195-7.
The effect of inoculation with indigenous naturally occurring microorganisms (an arbuscular mycorrhizal (AM) fungus and rhizosphere bacteria) isolated from a Cd polluted soil was assayed on Trifolium repens growing in soil contaminated with a range of Cd. One of the bacterial isolate showed a marked PGPR effect and was identified as a Brevibacillus sp. Mycorrhizal colonization also enhanced Trifolium growth and N, P, Zn and Ni content and the dually inoculated (AM fungus plus Brevibacillus sp.) plants achieved further growth and nutrition and less Cd concentration, particularly at the highest Cd level. Increasing Cd level in the soil decreased Zn and Pb shoot accumulation. Coinoculation of Brevibacillus sp. and AM fungus increased shoot biomass over single mycorrhizal plants by 18% (at 13.6 mg Cd kg(-1)), 26% (at 33.0 mg Cd kg(-1)) and 35% (at 85.1 mg Cd (kg(1)). In contrast, Cd transfer from soil to plants was substantially reduced and at the highest Cd level Brevibacillus sp. lowered this value by 37.5% in AM plants. Increasing Cd level highly reduced plant mycorrhization and nodulation. Strong positive effect of the bacterium on inocula, are important in plant Cd tolerance and development in Cd polluted soils.
从镉污染土壤中分离出的本土自然存在的微生物（一种丛枝菌根（AM）真菌和根际细菌）接种到生长在不同镉污染土壤中的白三叶草上，测定其效果。其中一种细菌分离物表现出显著的植物促生菌（PGPR）效应，被鉴定为短芽孢杆菌属。菌根定殖也促进了白三叶草的生长以及氮、磷、锌和镍的含量，双重接种（AM真菌加短芽孢杆菌属）的植株实现了进一步生长和营养吸收，且镉浓度更低，尤其是在镉含量最高时。土壤中镉含量的增加降低了地上部锌和铅的积累。短芽孢杆菌属与AM真菌共同接种使地上部生物量比单接种菌根的植株分别增加了18%（镉含量为13.6毫克/千克时）、26%（镉含量为33.0毫克/千克时）和35%（镉含量为85.1毫克/千克时）。相反，从土壤到植物的镉转移显著减少，在镉含量最高时，短芽孢杆菌属使AM植株中的这一值降低了37.5%。镉含量的增加极大地降低了植物的菌根形成和结瘤。该细菌对接种物的强烈积极作用，在镉污染土壤中植物对镉的耐受性和生长发育方面很重要。
