CAJ | 학술논문

沉水植物表面附着微生物系统是水生态的重要组成部分，然而当前对其了解仍不清楚．南京市花神湖是一个城市湖泊，沉水植物生长区域面积占湖面面积的40％左右．尽管花神湖的氮、磷营养盐水平很高，但最近未发生过藻类水华现象．本文以南京市花神湖中自然生长的优势种菹草（ Potamogeton crispus）、伊乐藻（ Elodea nuttallii）和金鱼藻（ Ceratophyl-lum demersum）为研究对象，利用扫描电镜和荧光显微镜观测了叶表面附着微生物群落的分布特征，测定了植物表面附着微生物的密度及附生藻类的种类、密度和优势种群，并比较分析了不同水生植物之间附生藻类的差异性．结果表明，沉水植物表面微生物群落的分布与物种和叶龄有关．3种沉水植物中，菹草表面微生物群落结构最为复杂，微生境最为丰富．底部老叶片上面附着较多的微生物且表现出较高的生物多样性．植物表面附着微生物密度大小顺序为：菹草＞金鱼藻＞伊乐藻；植物表面附生藻类密度大小顺序为：菹草＞金鱼藻＞伊乐藻．总体来讲，沉水植物表面微生物总量大概比藻类数量高1～2个数量级．这为深入研究沉水植物及其表面微生物的生态功能奠定了基础．
침수식물표면부착미생물계통시수생태적중요조성부분，연이당전대기료해잉불청초．남경시화신호시일개성시호박，침수식물생장구역면적점호면면적적40％좌우．진관화신호적담、린영양염수평흔고，단최근미발생과조류수화현상．본문이남경시화신호중자연생장적우세충저초（ Potamogeton crispus）、이악조（ Elodea nuttallii）화금어조（ Ceratophyl-lum demersum）위연구대상，이용소묘전경화형광현미경관측료협표면부착미생물군락적분포특정，측정료식물표면부착미생물적밀도급부생조류적충류、밀도화우세충군，병비교분석료불동수생식물지간부생조류적차이성．결과표명，침수식물표면미생물군락적분포여물충화협령유관．3충침수식물중，저초표면미생물군락결구최위복잡，미생경최위봉부．저부로협편상면부착교다적미생물차표현출교고적생물다양성．식물표면부착미생물밀도대소순서위：저초＞금어조＞이악조；식물표면부생조류밀도대소순서위：저초＞금어조＞이악조．총체래강，침수식물표면미생물총량대개비조류수량고1～2개수량급．저위심입연구침수식물급기표면미생물적생태공능전정료기출．
Submerged plants-epiphytic microbes system is an important component of aquatic ecosystems , but little is known about their status and roles.Lake Huashen is an urban lake, where submerged plants occupied about 40%of the water surface.Although concentrations of nutrients (P and N) were high in Lake Huashen, the algal blooms have never occurred in recent years.In order to explain this phenomenon in Lake Huashen , we determined the density of epiphytic microbes and dominant epiphytic algae atta-ched on the surface of three submersed macrophytes including Potamogeton crispus, Elodea nuttallii and Ceratophyllum demersum, investigated their distribution using the scanning electron microscopy and fluorescence microscopy and further compared the differ-ence in algae composition among three plants.The results showed that the distribution of microbial communities on leaf surface were related to the foliar age and species of submerged plant.Among the three submerged plants, a higher density and complex structures of epiphyticmicrobial community were found on leaf surface of Potamogeton crispus as compared to the other two plants. The quantity of algae and epiphytic microbes were higher on lower leaves of plants than that on the upper leaves .The densities of epiphytic microbes among three plants were in sequence:Potamogeton crispus >Ceratophyllum demersum >Elodea nuttallii, and as for algae, in sequence Potamogeton crispus >Elodea nuttallii >Ceratophyllum demersum.In general, the number of total epi-phyticmicrobes is about 1 2 orders higher than that of algae .The study provided useful information to study the structure and func-tion of submerged plants-epiphytic microbes system.