盐分胁迫对沿海绿竹光合作用及叶绿素的影响

Study on Impact of Photosynthesis and Chlorophyll of Dendrocalamopsis oldhami Grown in the Coastal Areas Under Salt Stress

通过对盐分胁迫条件下绿竹的光合作用变化的研究 ,可知在盐分胁迫处理的第 2 5天处理为 2 .0 %下的绿竹的净光合速率、光呼吸速率比对照分别下降了 4 7.6 %、4 0 %,而 0 .4 %的净光合速度却增加了 6 .6 %、光呼吸速率下降了 15 .1%;到第 4 6天 2 .0 %的比对照分别下降了 5 1.8%、4 6 .7%,0 .4 %的分别下降了 5 .8%、31.9%;绿竹的暗呼吸速率则没有一定的规律 ,但还是盐浓度越高 ,暗呼吸速率下降得越快 ;绿竹的叶绿素变化则是呈现先上升而下降的趋势 ,0 .4 %的盐分胁迫强度为盐分的一个分界点 ,大于 0 .4 %的光合作用受到明显的影响 ,小于 0 .4 %的光合作用受到影响不明显。

Through study of photosynthesis change of Dendrocalamopsis oldhami under salt stress, it is found that net photosynthesis rate and light respiratory rate declines by 47.6% and 40% respectively in the 25 th day under salt stress as salt content is up to 2.0% as compared to the contrast test, but net photosynthesis rate with salt content of 0.4% increases by 6.6%, and light respiratory rate declines by 15.1%; in the 46 th day, net photosynthetic rate and light respiratory rate declines by 51.8% and 46.7% respectively with salt content of 2.0%, while net photosynthetic rate with salt content of 0.4% declines by 5.8% and light respiratory rate declines by 31.9%. Dark respiratory rate of D.Oldhami has no definite pattern, but the higher the salt content, the quicker the dark respiratory rate declines. The chlorophyll of D.oldhami shows the tendency being up firstly and down later.Salt content of 0.4% is a threshold for salt stress,i.e.the photosynthesis rate is obviously affected in case salt content is over 0.4%,and is slightly below 0.4%.