水温波动对泰来草、圆叶丝粉草生理及生长特性的影响OA北大核心CSTPCD

In order to explore the adaptability and adaptation mechanism of seagrass to water temperature fluc-tuation,this study designed a water temperature fluctuation environment with fluctuation ranges of 0,2,4,6,8 and 10℃,and took 27℃as the fluctuation center.Thalassia hemprichii and Cymodocea rotundata were planted in the above environment.At the end of the experiment,14 indexes of growth status,oxidation and antioxidant products,osmotic adjustment substances,photosynthetic pigments and photosynthetic fluores-cence characteristics were measured to evaluate the changes of physiological and growth characteristics.The results showed that compared with the constant water temperature,the aboveground productivity of the two species of seagrasses was higher when the water temperature amplitude was 2-4℃.The antioxidant enzyme activity and cell osmotic adjustment substance content were lower,and the electron transfer rate of nutrient and chlorophyll content and light reaction was higher,which showed a better growth status in general.How-ever,as the water temperature amplitude exceeded this range,the above indicators showed the opposite trend,and the peroxidation stress of seagrass increased gradually.Although seagrass can still resist this stress by increasing the activity of antioxidant enzymes and the content of cell osmotic potential regulating sub-stances,the resistance is limited.The environment with a amplitude of more than 8℃was not conducive to the growth of the two species of seagrass.In addition,with the increase of water temperature fluctuation,the changes of physiological indexes of C.rotundata were all greater than those of T.hemprichii.Therefore,this study suggested that the sensitivity of C.rotundata to water temperature fluctuation was higher than that of T.hemprichii.