AM真菌对采煤沉陷区黄花菜生长及根际土壤养分的影响

于陕北黄土沟壑采煤沉陷区内布设试验小区,对黄花菜(Hemerocallis citrina Baroni)接种丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)—摩西管柄囊霉菌,通过测定黄花菜光合性能、植株生长、抗逆性、土壤养分含量、根际微生物数量等,揭示AM真菌对黄花菜生长和土壤养分的影响。结果表明,黄花菜种植3—5个月后,接种AM真菌显著提高了黄花菜株高、冠幅及其根系菌根侵染率、菌丝密度。与不接种对照区相比,接种AM真菌后黄花菜叶片的光合速率、可溶性糖含量和过氧化氢酶活性分别提高了51%、12%、79%。接种AM真菌处理区黄花菜根际土壤的电导率、有机质、碱解氮和速效钾含量等均显著高于对照区,细菌数量和磷酸酶活性的菌根贡献率分别达77%和24%。表明采煤沉陷区扰动土壤接种AM真菌具有增强土壤微生物活性、改善土壤肥力和提高黄花菜植株抗逆性的作用,对促进陕北黄土沟壑采煤沉陷区经济作物生长和提高土壤质量具有重要现实生态意义。

Effects of arbuscular mycorrhizal fungi on daylily growth and soil fertility in a coal mining subsidence area of northern Shaanxi

Effects of arbuscular mycorrhizal fungi (AM) on the growth of daylily (Hemerocallis citrina Baroni) and soil fertility were investigated by measuring daylily growth, soil nutrition contents, soil microbial population, and enzyme activities in a coal mining subsidence loess hilly area of northern Shaanxi. Results showed that AM fungal inoculation significantly increased plant height and crown width, mycorrhizal colonization rate, and hyphal density. Compared with control, AM fungal inoculation increased leaf photosynthesis rate, soluble sugar content, and catalase activity by 51%, 12%, and 79%, respectively. Moreover, the soil conductivity and organic matter, available nitrogen, and potassium content in the rhizosphere soil were significantly higher in mycorrhizal plants than control, and the contribution rates of AM fungal inoculation to bacteria population and acid phosphatase activity in rhizospheric soil were 77% and 24%, respectively. This showed that AM fungal inoculation may play an important role in enhancing plant resistance stress and improving soil fertility, soil microbial population, and enzyme activities. It will have an important value in promoting the growth of cash crops and further research on degraded land reclamation.