不同种植年限桉树人工林根际土壤微生物的活性

Microbial Activity of Rhizosphere Soil of Eucalyptus Plantation with Different Planting Years

为桉树人工林可持续高效经营和生态环境保护提供科学依据,利用改良高盐法结合硫酸铝铵、PVPP联用去除腐植酸直接提取土样DNA,采用微孔板检测技术测定根际土壤酶活性等方法,研究不同年限桉树人工林根际土壤微生物的活性。结果表明:磷酸酶、β-葡糖糖苷酶、多酚氧化酶和过氧化氢酶酶活力均随桉树种植年限的增加呈显著的下降趋势。1年生桉树人工林根际土壤中细菌和真菌数量明显高于对照,随种植年限的增加也呈明显的下降趋势,且根际土壤中真菌数量更易受种植年限的影响。在参与氮循环的基因中,固氮基因(nifH)、氨氧化古菌硝化基因(amoA)、氨氧化细菌硝化基因(amoA)和反硝化基因(nosZ)的数量均随种植年限增加呈显著降低趋势。桉树人工林的种植对根际土壤中微生物群落的构成和功能均有明显改变。

To provide the scientific reference for sustainable efficient management and ecological environmental protection of Eucalyptusplantation,the enzyme activities,the number of soil microbial communities（16SrRNA gene and 18SrRNA）and the functional gene of nitrogen cycle of rhizosphere soil in Eucalyptus plantation with different planting years were analyzed by microplate enzyme detection and Q-PCR technology.The results showed that the activities of phosphatase,β-glucosidase,polyphenol oxidase and catalase increased significantly with the increase of the age of Eucalyptus grandis.The number of bacteria and fungi of rhizosphere soil in 1year old stands significantly higher than that of the control group and 3~5year old stands,and the number of fungi are more susceptible to cultivation age.The number of nitrogen fixation gene nifH,nitrification function gene amoA,and denitrification genes nosZ were also significantly decreased with the increase of the planting age.The plantation of E.grandis had obviously changes the composition and function of microbial community of the rhizosphere soil.