倒置显微镜拍照法对浮游植物计数的稳定性分析

准确定量分析湖泊河流中浮游植物群落结构对评价湖泊河流健康和保障人类饮水安全至关重要.显微镜镜检法是定量分析浮游植物群落结构的唯一方法,但不能满足浮游植物计数分析要求.在Utermhl倒置计数管视野法基础上提出倒置显微镜拍照法,使用拍照法对小球藻、四尾栅藻、斜生栅藻3种纯藻样品和鄱阳湖野外样品计数得到:1)在5、10倍物镜下拍照因浮游植物个体太小导致计数不准确,在20、40倍物镜下拍照计数准确,增加拍照次数可较好地避免计数偏差,拍照次数是影响拍照法计数分析的主要因素; 2)小球藻、四尾栅藻、斜生栅藻在20和40倍物镜下分别拍摄5和10张照片时每升浮游植物计数稳定;鄱阳湖野外样品在20和40物镜倍下分别拍摄5、10张照片时每升浮游植物计数稳定; 3)倒置显微镜拍照法比计数框行格法、目镜视野法、目镜行格法和Utermhl倒置计数管视野法计数稳定,变异系数最小为0.812.

The stability of phytoplankton counting with inverted microscope

Accurate and quantitative analysis of phytoplankton communities in lakes and rivers is very important to evaluate the health of lakes and rivers and ensure the safety of human drinking water. Microscopic examination is the only method for quantitative analysis of phytoplankton community structure, but it can not meet the requirement of phytoplankton count analysis. Based on the vision field method with an Utermöhl inverted counter, the method of using photograph taken by inverted microscope is put forward. This approach was used to count the three kinds of pure algae samples and Lake Poyang field samples and we found that: 1) The count is not accurate with the magnification of 5 or 10 times because the phytoplankton is too small, but accurate for 20 or 40 times. The number of photos is the main factor affecting the counting and analysis of the photo method, with higher accuracy for large numbers of photo-taken times. 2) For all the samples, the counting results are stable when taking 5 or 10 photos with magnifications of 20 or 40 times. 3) The method of inverted microscope photograph is more stable than that of counting frame, eyepiece field of view, and Utermöhl inverted counter field of view, with a minimum variation coefficient of 0.812.