对济南市护城河(解放阁)水质及底泥沉积物中细菌菌群进行检测分析。水质理化指标的检测按照国家标准进行;用平板计数法检测河底淤泥中的细菌数量;用MPN法检测肠道菌群及硝化细菌、亚硝化细菌和反硝化细菌的数量;用16S r DNA部分测序技术对可培养细菌进行分类分析;用高通量测序技术(V4区)对细菌菌群的多样性进行分析。水质理化指标的检测结果表明:护城河水质整体良好。基于微生物培养技术的细菌菌群分析结果表明:底泥中存在较低数量的大肠菌群,硝化细菌和亚硝化细菌数量接近,反硝化细菌数量较高。可培养细菌中还存在多种水生细菌和其它土壤细菌,其中芽孢菌是最常见的分离菌。高通量分析结果表明:护城河底泥中的细菌具很高的多样性,如在属的分类水平上有548个单元,在科的分类水平上有392个单元。研究结果表明:高通量测序技术能提供在不同分类水平上菌群多样性的全貌,信息丰富,但难以提供细菌类群的详细信息,如不能得到种的信息,也不能得到大部分属的信息(因为大部分属至今还没有被正式命名)。而传统的培养方法可以简便地分析特定菌群的数量,还能给出像大肠菌群数量、硝化细菌数量、病原菌的种类及数量等重要信息。因此,高通量测序技术和传统细菌培养方法相结合可弥补各自的局限性,为环境样本中微生物多样性分析提供更加全面和详尽的信息。
[Objective] The study aimed to investigate the early growth stage＇s response of invasive plant alligatorweed（Alternanthera philoxeroides） under salt stress.[Method] The alligatorweed was cultivated with four different NaCl concentrations 0（control）, 100, 200, 300 mmol/L diluted in 1/2 Hoagland＇s solution at early stage.During the period, we measured the number of nodes and leaves, length, fresh weight, dry weight and water content of stems to determine the effect of salt on alligatorweed growth. [Result] Compared with control, the node number, leaf number,length, fresh weight and dry weight of the stems significantly changed in NaCl solution, and the difference was positively related to NaCl concentration. We concluded that middle and high concentrations of NaCl significantly inhibited the growth of alligatorweed, by suppressing the node number, leaf number, length, fresh weight and dry weight of the stems. Among them, the stem length and fresh weight were more sensitive to NaCl stress. [Conclusion] The present result is helpful to understand the alligatorweed＇s adaptability to saline environment, and also helpful to prevent its invasion in such environment.
