丹江口水库隐头舟形藻的生长和光合荧光特性对不同氮素的响应  

Responses of growth and Chlorophyll photosynthetic fluorescence characteristics of Navicula cryptocephala to different nitrogen in Danjiangkou Reservoir

作　　者：郑传坤 刘晓真 李卫国[1] 贺玉晓[1] 赵同谦[1] ZHENG Chuankun;LIU Xiaozhen;LI Weiguo;HE Yuxiao;ZHAO Tongqian(Institute of Resources and Environment,Henan Polytechnic University,Jiaozuo 454000,China)

机构地区：[1]河南理工大学资源环境学院,河南焦作454000

出　　处：《海洋湖沼通报(中英文)》2025年第1期78-87,共10页Transactions of Oceanology and Limnology

基　　金：国家自然科学基金项目(U1704241);中原科技创新领军人才项目(194200510010)。

摘　　要：底栖硅藻因其生长位置相对固定、对水体环境变化敏感能够准确地反映水体水质的持续变化,被认为是淡水系统中水质及生态质量的指示物种。本研究采用稀释分离法和小液滴分离法,从丹江口水库分离了一株底栖硅藻。通过形态学观察和18S rDNA、LSU rDNA、rbcL的序列分析,鉴定其为隐头舟形藻。分别以硝酸钠、氯化铵和尿素作为氮源,分析了不同氮素营养条件下该藻生长和叶绿素荧光参数(F_(v)/F_(m)、α、I_(k)、ETR_(max))的变化特征。结果表明,隐头舟形藻在铵态氮、硝态氮和有机氮中均可正常生长,但生长及叶绿素荧光特性对不同氮素形态的响应有所不同。在21 d的培养周期内,隐头舟形藻的生长趋势为先缓慢增长而后快速分裂增殖,最后稳定下降;硝酸钠和尿素的培养条件下,隐头舟形藻的生长速率随氮素浓度的增加而相应增加,其中,硝酸钠条件下,隐头舟形藻的最大藻细胞密度及比生长速率最高;氯化铵培养基中,隐头舟形藻藻细胞密度及生长速率随氮素浓度的增加表现出先增加后降低的趋势。隐头舟形藻PSⅡ最大光能转化效率(F_(v)/F_(m))、最大相对电子传递速率(ETRmax)及半饱和光强(I_(k))值随着培养时间的延长表现为先上升而后下降;一定范围内提高氮素浓度增强了F_(v)/F_(m)、ETR_(max)、I_(k),而10 mg/L氨氮减弱了F_(v)/F_(m)、ETR_(max)、I_(k);第7天处于对数增长期的隐头舟形藻PSⅡ最大相对电子传递速率ETR_(max)相对较高;氮缺乏条件下的隐头舟形藻会提高光能利用率(α)。A strain of benthic algae was isolated from the sediment samples collected in Danjiangkou Reservoir using dilution separation and small droplet separation methods.Based on morphological observation and homologous analysis of 18S rDNA,LSU rDNA and rbcL sequences,the strain of diatom SG0529 obtained from Danjiangkou Reservoir was identified as Navicula cryptocephala.Using sodium nitrate,ammonium chloride and urea as nitrogen sources,the change characteristics of the growth and chlorophyll fluorescence parameters(Fv/Fm,α,Ik,ETRmax)of N.cryptocephala under different nitrogen conditions were analyzed.The results showed that the strain of N.cryptocephala grew normally in sodium nitrate,ammonium chloride and urea medium,but the responses to different nitrogen forms were quite different.In sodium nitrate and urea medium,the specific growth rate and the cell density of N.cryptocephala increased with increment of nitrogen concentration.Under ammonium chloride culture condition,the growth rate of N.cryptocephala increased firstly and then reduced as nitrogen concentration increased in culture medium.With the increase of sodium nitrate and urea concentration,the photosynthesis performance of N.cryptocephala increased,and the high concentration of ammonium chloride condition inhibited its photosynthesis reaction,indicating that increasing the concentration of nitrogen within a certain range is beneficial to the growth of N.cryptocephala,improving its photochemical reaction,and high concentration of ammonium nitrogen inhibited its growth and photosynthesis reaction.Compared with ammonia and urea,nitrate was more able to promote the growth of N.cryptocephala.Under the condition of nitro nitrogen culture,the maximum cell density and growth rate of N.cryptocephala are optimal.In addition,N.cryptocephala improved the rate of PSII electron transfer,accelerate the use of light energy,to provide energy for the absorption of nitrate.Moreover,N.cryptocephala improvedαvalue to increase the utilization efficiency of light energy in res

关 键 词：隐头舟形藻 分子鉴定 氮素 生长特性 叶绿素荧光 

分 类 号：X172[环境科学与工程—环境科学]