不同植物对沟渠沉积物反硝化速率及功能基因的影响研究  

Effects of plant species on denitrification and functional genes in ditch sediment

作　　者：刘莲 汪涛[1,3] 任晓[1,2,3] 邵志江 郑斌[1,2,3] LIU Lian;WANG Tao;REN Xiao;SHAO Zhijiang;ZHENG Bin(Institute of Mountain Hazards and Environment, Chinese Academy of Science, Chengdu 610041;University of Chinese Academy of Sciences, Beijing 100049;Key Laboratory of Mountain Environment Evolvement and Regulation, Chengdu 610041)

机构地区：[1]中国科学院、水利部成都山地灾害与环境研究所,成都610041 [2]中国科学院大学,北京100049 [3]中国科学院山地表生过程与生态调控重点实验室,成都610041

出　　处：《环境科学学报》2019年第6期1808-1815,共8页Acta Scientiae Circumstantiae

基　　金：国家重点研发计划(No.2017YFD0800105);国家水污染治理与控制专项(No.2017ZX07101-001);国家自然科学基金项目(No.41371462)

摘　　要：植物是影响沉积物反硝化作用的重要因素之一,国内外已有不少研究探讨了植物对河口或湖泊沉积物反硝化速率的影响,但关于植物类型对自然沟渠沉积物反硝化速率及其相应功能基因的影响研究不多.因此,本文以7种常见沟渠植物为研究对象,通过室内盆栽试验,利用改进的乙炔抑制法和实时荧光定量PCR技术研究了不同植物对自然沟渠沉积物反硝化速率和相应功能基因(nirS和nirK)拷贝数的影响.结果表明,培养至第180 d时,不同植物生长条件下沉积物反硝化速率在2.85~13.20μg·m^-2·h^-1之间,不同植物间反硝化速率差异显著,且大型挺水植物>浮水植物>小型挺水植物.不同植物之间沉积物中nirS基因拷贝数在2.70×10^8~5.02×10^8 copies·g^-1之间,nirK基因拷贝数在3.97×10^5~6.91×10^5 copies·g^-1之间,与培养初期相比,培养180 d后沉积物中nirK、nirS基因拷贝数明显增多.7种植物中,美人蕉沉积物中的反硝化功能基因拷贝数较高,狐尾藻较低,整体来看,基因拷贝数大小顺序为:挺水植物>浮水植物.nirS基因拷贝数与NO-3-N含量、TN含量及反硝化速率之间均呈显著性的正相关关系(p<0.05),但nirK基因拷贝数与沉积物碳氮含量及反硝化速率之间相关性不显著.The influence of plant on the denitrification of sediment in the estuary or lake have been reported by many studies. However, the effects of plant species on the denitrification of sediment and function genes in the natural ditches is still not clear. Here, we explored the effects of seven ditch plants on denitrification and functional genes (nirS, nirK) in ditch sediment via pot experiments by using the chloramphenicol.amended acetylene inhibition procedure and real time.PCR. The results show that the denitrification rates of the sediment under different plant species ranged from 2.85 μg·m^-2·h^-1 to 13.2 μg·m^-2·h^-1 after 180 days. The denitrification rates were as follows: Macrophytes> floating plants> small emerged plants, and there was a significant difference among different plant species. The gene abundances of nirS ranged from 2.70× 10^8 copies·g^-1 to 5.02× 10^8 copies·g^-1, and the gene abundances of nirK ranged 3.97×10^5 copies·g^-1 to 6.91×105 copies·g^-1. Furthermore, the gene abandunces of nirK and nirS increased significantly after 180 days of incubation. The denitrification functional gene copies was the highesin the sediment of Canna indica, while the lowest in Myriophyllum spicatum. The gene abundances of emerged plants were higher than that of floating plants. Moreover, pearson correlation analysis showed that there was a significant positive correlation between nirS and NO3^--N content, TN content, and denitrification rate (p<0.05), but the correlation between nirK and sediment physicochemical properties, denitrification rate were not significant.

关 键 词：植物类型 沟渠沉积物 反硝化速率 NIRK nirS 

分 类 号：X522[环境科学与工程—环境工程]