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以实验室栽培的互花米草为研究对象,室内模拟研究0、10和20 cm淹水水位下2、4、6、12和24 h/d淹水胁迫对互花米草叶绿素含量及快速光响应曲线变化影响。结果显示:(1)0 cm淹水处理下,淹水时间越长有利于提高互花米草叶片叶绿素含量,而在10 cm和20 cm淹水处理下,4 h/d和6 h/d淹水处理叶绿素含量高于其他淹水时间处理;从相同淹水时间来看,4 h/d和6 h/d条件下,淹水水位较高时互花米草叶片叶绿素含量较高;(2)0 cm淹水处理下,随淹水时间的增加类胡萝卜素含量增大;20 cm处理下淹水4 h/d和6 h/d类胡萝卜素含量分别比淹水2 h/d高34%和38%;(3)较高较长时间和淹水水位胁迫都使互花米草的光合电子传递效率明显下降,并且最小饱和光照强度总体变化也呈下降趋势;0 cm淹水条件下,最大光合电子传递速率均在40μmol/(m2.s)以上,而20 cm淹水条件下均在40μmol/(m2.s)以下。虽然较高淹水水位及较长淹水时间对互花米草基株光合电子传递效率有明显抑制作用,但淹水20 cm处理下4 h/d和6 h/d光合色素含量仍较高,只有24 h全天淹水的互花米草死亡,表明了互花米草在较低潮滩带定居及扩张具有较大的可能性。
Taking Spartina alterniflora cultivated in the laboratory as the research object, indoor simulation was conducted to study the effects of 2, 4, 6, 12 and 24 h / d flooding stress on the chlorophyll content and rapidity of Spartina alterniflora at 0, 10 and 20 cm flooding levels Light response curve changes. The results showed that: (1) Under the 0 cm flooding treatment, the longer the flooding time was, the better the chlorophyll content was in the leaves of Spartina alterniflora. Under flooding treatment of 10 cm and 20 cm, the flooding time was 4 h / d and 6 h / d The chlorophyll content of flooding treatment was higher than that of other flooding treatments. From the same flooding time, chlorophyll content of Spartina alterniflora was higher under 4 h / d and 6 h / d conditions. ( 2) At 0 cm flooding, the content of carotenoids increased with flooding time; the content of carotenoids at 4 and 6 d after flooding at 20 cm was 2 h / d higher than that under flooding 34% and 38%, respectively. (3) The photosynthetic electron transfer efficiency of Spartina alterniflora decreased significantly with higher and longer time and flooding water stress, and the overall change of minimum saturated light intensity also showed a downward trend. , The maximum photosynthetic electron transfer rates were above 40μmol / (m2.s), while those under 20 cm flooding were below 40μmol / (m2.s). Although the higher flooding water level and longer flooding time significantly inhibited the photosynthetic electron transfer efficiency of Spartina alterniflora, the content of photosynthetic pigments at 4 h / d and 6 h / d after flooding 20 cm was still high , Only the death of Spartina alterniflora, which was flooded 24 hours a day, showed that Spartina alterniflora was more likely to settle and expand in the lower tidal flats.