黄连须根浸提液对土壤微生物及酶活性的影响  

Effect of fibrous root extract of Coptis chinensis on soil microbes and enzyme activities

作　　者：李阳波[1] 何林卫 张薇[1] 吴叶宽[1] 袁玲[1] 黄建国[1] 

机构地区：[1]西南大学资源环境学院,重庆400716

出　　处：《中国中药杂志》2014年第21期4205-4210,共6页China Journal of Chinese Materia Medica

基　　金：重庆市科委自然科学基金项目(cstc2011jj A0861)

摘　　要：黄连Coptis chinensis是大量使用的中药材,连作障碍严重。试验在供试土壤中加入不同浓度的黄连须根浸提液(REC),研究了它们对土壤微生物和酶活性的影响。结果表明,在加入REC的土壤中,微生物碳氮量显著降低,细菌和放线菌比对照降低约60%,但真菌增加3倍左右。自生固氮菌、磷细菌、钾细菌、硝化细菌和氨化细菌均显著减少,说明土壤固(供)氮、溶磷、解钾、促生等功能受到抑制。REC对土壤酶活性的影响表现出多样性,提高转化酶活性,降低脲酶活性,对脱氢酶活性无显著影响,妨碍了土壤生物化学反应的有序进行。此外,REC减少微生物标记性磷脂脂肪酸(PLFAs)种类,降低PLFAs总量,提高真菌/细菌PLFAs比值,说明REC在抑制细菌繁殖生长的同时,相对的增加了真菌数量,致使后续作物容易发生真菌病害。REC还显著降低土壤微生物群落的多样性和均匀度指数,说明加入REC恶化了土壤生态环境,使微生物种群减少,密度降低。因此,在黄连生长过程中,根系分泌的化感物质可能改变土壤微生物种群结构,造成连作障碍。Coptis chinensis is widely used as Chinese medicine herbs and serious soil problems occur after continual cuhivation of this medicinal plant. In the preset experiment, fibrous root extract of C. chinertsis （REC） was added into soil to study the effect of REC on microbes and enzyme activity in soil. The results showed that both bacteria and actinomycetes decreased by about 2 times in contrast to fungi,which increased by about 3 folds. Phosphorus bacteria, potassium bacteria, azotobacter, ammonia bacteria, and nitrifying bacteria were also reduced significantly by REC, suggesting the inhibition of nitrogen biofixation and supply, mobilization of phosphorus and potassium, ad plant growth promotion as REC added into soil. There were multiple influences of REC on soil enzyme activities. Invertase activity was stimulated, while urease was inhibited and dehydrogenase unchanged by REC, indicating the interference of biochemical reactions in soil. In addition, type and total content of phosphorus lipid fatty acids （ PLFAs）, the signature of microbes, decreased while the ratio of bacterium to fungus PLFAs increased as REC increased in soil, which suggested that fungi increased rela- tively with bacteria decreased thereby leading to easy occurrence of crop fungus diseases following cultivation of C. chinensis. The decrease in diversity and evenness indexes of microbial community in soil by REC indicated soil ecosystem deterioration and reduction of microbial groups and densities in soil. Therefore, allelopathic chemicals released from the roots of C. chinensis could change microbial community structure and resulted in serious soil problems by continual cropping of this medicinal plant.

关 键 词：黄连 土壤 微生物 酶 

分 类 号：S154[农业科学—土壤学]