接种AM菌对西部黄土区采煤沉陷地柠条生长和土壤的修复效应

Effects of arbuscular mycorrhizal fungi on the growth of Caragana korshinskii Kom. and soil improvement of coal mining subsidence in the Loess Area of West China

以采煤沉陷区柠条为宿主植物,研究接种丛枝菌根真菌(arbuscular mycorrhizal fungi,简称AM菌)对柠条生长和根际土壤的改良效应。结果表明:8月份接种AM菌比不接菌柠条的株高、冠幅和地径显著增加了29.11%,29.83%和14.81%,9月份接菌区柠条的根长、平均直径、根表面积和根体积分别比对照区增加了151.0%,34.2%,116.0%和129.3%。接种AM菌增强柠条的抗逆性,接菌区的柠条叶片可溶性糖含量和过氧化氢酶活性分别比对照区增加了13.4%和111.1%。8月份接种AM菌改善了土壤的生物理化性质,接菌区有机质、碱解氮、速效磷和速效钾比对照区分别增加7.06g/kg,140.0 mg/kg,1.82 mg/kg和16.72mg/kg,接种AM菌显著增加了根际土壤中真菌、放线菌、细菌数量和酸性磷酸酶活性。总之,接种AM菌促进采煤沉陷区柠条的生长和土壤的改良。

China is a country with large amount of consumption and production of coal. However, the exploitation and utilization of coal have resulted in series of ecological environmental problems. The main problem is the destruction of land resources, as coal mining is occupies a large amount of land and destroys surface vegetation. This leads to land subsidence and a large number of cracks, which injures plant roots, thereby affecting plant growth and nutrient uptake, increasing soil nutrients and moisture loss, and reducing soil fertility. As a result, research has been focused on the ecological restoration of mining areas in recent years, including the use for microbial reclamation of arbuscular mycorrhizal （AM） fungi that can form a symbiotic association with 〉 80% terrestrial plants. They promote the absorption and utilization of mineral elements and growth of plants, and improve the plants resistance to adverse environment. The effect of AM fungi on the restoration of the mining areas with sandy substrates has been previously studied. However, little is known about the effect of AM fungi on the vegetation and soil restoration in loess mining areas. The present study determined the effects of AM fungi on the growth of the host, Caragana, a loess pioneer plant, and the improvement of rhizosphere soil. The results show that the height, crown, and ground diameter of Caragana inoculated by AM fungi were greater by 29.11%, 29.83%, and 14.81%, respectively in August, than in non-inoculated plants in September. The root length, average diameter, surface area, and root volume of inoculated Caragana were greater by 151%, 34.2%, 116.0%, and 129.3%, respectively, than those of the control. In addition, inoculation of AM fungi enhanced Caragana resistance; the soluble sugar content and catalase activity in the leaves of inoculated Caragana increased by 13.4% and 111%, respectively. Moreover, Caragana inoculated with AM improved the biological, physical, and chemical properties of soil; the organic matter, available nitrogen, phosphorus, and potassium increased by 7.06 g/kg and 140, 1.82, and 16.72 mg/kg, respectively in August. Inoculation with AM significantly increased the number of fungi, actinomycetes, and bacteria, and also increased acid phosphatase activity of the rhizosphere soil. Therefore, AM fungal inoculation promoted Caragana growth and soil improvement in loess coal mining subsidence areas.