牛山湖浮游生物群落DNA指纹结构与理化因子的关系

Relationship between DNA fingerprinting structure of plankton community and physicochemical factors in Lake Niushan

对牛山湖5个站点的浮游生物群落DNA多态性进行了RAPD指纹和PCR-DGGE指纹分析,并探讨了其与理化因子的关系.结果如下:1)从40条随机引物中筛选出9条引物,共获得93条谱带,多态率为58%;各站点所得谱带平均为67条,其中Ⅰ站最少,为61条,Ⅴ站最多,为74条;2)PCR-DGGE指纹图谱共含102条谱带,其中原核生物56条,真核生物46条,谱带总数以Ⅲ站、Ⅳ站和Ⅴ站较多,Ⅰ站和Ⅱ站较少;3)Ⅱ站的总磷、叶绿素、化学耗氧量、硬度及电导率最高;各站点间溶氧和pH差异较小.相似性聚类分析表明,浮游生物群落DNA指纹将5个站点划分为两支,Ⅰ站和Ⅱ站聚为一支,Ⅲ站、Ⅳ站和Ⅴ站聚为另一支,理化因子将Ⅰ站、Ⅲ站、Ⅳ站和Ⅴ站聚为一支,Ⅱ站单独聚为一支.研究表明牛山湖浮游生物群落DNA指纹结构与理化因子具有一定的相关性,并且与环境主要限制因子总磷的含量是密切相关的.因此,浮游生物群落级水平DNA分析能简便、准确、迅速地反映水质状况,这方面资料的积累可以为建立一种基于分子生物学简便而灵敏的水环境评价体系提供科学依据.

Plankton are considered good indicators of water quality because they are highly sensitive to the environmental variation in their short life spans. However, traditional studies on plankton community constructure have depended on taxonomic identification which has historically been a difficult task. Recently, different fingerprinting techniques have been developed and applied successfully to analyze the community structure of bacterial and picoplankton. However, little is known to the whole plankton community. In this study, we analyze DNA polymorphism of plankton communities in five different sampling stations of Lake Niushan by RAPD and PCR-DGGE and explore the relationship between DNA fingerprinting structure of plankton communities and environmental physico-chemical factors. The results were： （i） 9 of 40 screened random primers used in the study amplified a total of 93 observable bands, 58 of which were polymorphic; the mean number of amplified bands at different sampling stations was 67, and stationV had the maximum number （74） and station I had the minimum number （61）; （ii） a total of 102 bands （56 of 16S rDNA bands and 46 of 18S rDNA bands） were detected by PCR-DGGE, station III, ]V, and V had more bands, station I and II had few band; （iii） total phosphorus （TP）, chlorophyll-a, chemical oxygen demanded （COD）, hardness, and conductance rate at station II were the highest; dissolved oxygen （DO） and pH value were not obviously different among five stations. Based on physico-chemical factors, station I, III, IV, and V were grouped into a cluster, station II grouped into a single cluster. Based on RAPD markers and PCR-DGGE markers, five sampling stations can be grouped into two clusters： station I and II were grouped into a cluster, and station III, IV, and V were grouped into the other cluster. In conclusion, the DNA fingerprinting structure of plankton community was closely related to total phosphorus （TP）. DNA based community level analysis is a fast, easy, accurate method to reflect the water quality, and such data accumulation will play an important role in constructing one easy and sensitive molecular system for water quality assessment.