底栖细鞘丝藻和苦草对光照强度的响应策略  

Response strategies of Leptolyngbya sp. and Vallisneria natans to light intensity

作　　者：舒柔 何海涛 陈武琦 裴国凤[1] SHU Rou;HE Haitao;CHEN Wuqi;PEI Guofeng(College of Life Sciences,South-central University for Nationalities,Wuhan 430074,China)

机构地区：[1]中南民族大学生命科学学院,武汉430074

出　　处：《应用与环境生物学报》2021年第6期1577-1582,共6页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目(30970550);中央高校基本科研业务费专项基金项目(CZY20002)资助。

摘　　要：底栖藻类和沉水植物是浅水湖泊的重要初级生产者,是恢复与重建的主要对象,主要受到水体营养状况、附着藻类和光照等环境因子的影响.通过室内模拟实验,测定不同光照强度下处理系统的水体理化因子、底栖细鞘丝藻和苦草生物量、苦草丙二醛含量等指标,评估光照对底栖细鞘丝藻和苦草生长的影响.结果显示水体pH、DO与光照强度显著正相关(P <0.05);底栖细鞘丝藻在弱光照下(≤2 mol m^(-2)s^(-1))的生物量较低,中等光照(9-18 mol m^(-2)s^(-1))条件下的生物量最高,当光照强度≥27 mol m^(-2)s^(-1)时,细鞘丝藻由呈丝状附着生长的底栖藻转变为浮游生长的藻殖段,使水体Chl a浓度峰值最高达到146μg/L.此外,中等光照强度下的底栖细鞘丝藻能够有效缓冲水体磷浓度,抑制了沉积物磷释放.苦草的生物量随着光照强度的增强而增加,而苦草在中等光照强度下的叶片最长,表明底栖细鞘丝藻对苦草的生长没有明显抑制作用.上述结果表明,底栖细鞘丝藻和苦草生长的最适光照强度不同,底栖细鞘丝藻通过改变生长方式响应光照环境的变化;而苦草通过生物量分配适应不佳的光照环境;光照强度通过影响底栖藻类和沉水植物的生理活动直接或间接地调控水体理化因子和沉积物氮、磷的释放.Benthic algae and submerged macrophytes are important primary producers in shallow lakes and the main focus of restoration and reconstruction. They are mainly affected by environmental factors such as water nutrition, epiphytic algae, and light. In this study, indoor simulation experiments were conducted to determine the water physicochemical factors, biomass of Vallisneria natans and Leptolyngbya sp., and the malondialdehyde content of Vallisneria natans under different light intensity treatments and to assess the effects of light on the growth of Vallisneria natans and Leptolyngbya sp. The results showed that pH and DO were significantly positively related to light intensity(P < 0.05), the biomass of Leptolyngbya sp. under weak light(≤2 mol m^(-2)s^(-1)) was low, and the biomass was the highest under moderate light conditions(9-18 mol m^(-2)s^(-1)). When light intensity was ≥ 27 mol m^(-2)s^(-1), the Leptolyngbya sp. was transformed from filamentous benthic algae to planktonic hormogonia, and the peak Chl concentration in the water column reached 146 μg/L. Furthermore, Leptolyngbya sp. under moderate light intensity can effectively inhibit the release of phosphorus from sediments. The biomass and plant reproductive capacity of Vallisneria natans increased with increased light intensity, and the leaves of Vallisneria natans under moderate light intensity were the longest, with a mean of that Leptolyngbya sp. have inapparent inhibitory effect on the growth of Vallisneria natans. Our results indicate that the optimal light intensity is different for the growth of Vallisneria natansand Leptolyngbya sp. Leptolyngbya sp. responds to changes in light intensity by changing its growth mode,while Vallisneria natans changes its biomass allocation pattern to adapt to the poor surrounding light. Light intensity directly or indirectly regulates the physicochemical factors in the water column and the release of nitrogen and phosphorus from sediments by affecting the physiological activities of benthic algae and submerged

关 键 词：光照强度 底栖藻类 沉水植物 生物量 理化因子 

分 类 号：Q945.11[生物学—植物学]