磷胁迫对水曲柳幼苗潜在光合速率的影响

磷胁迫是森林树木常常遭遇到的逆境。在磷胁迫条件下森林树木的形态和生理功能发生很大的变化。以一年生水曲柳幼苗为实验材料,研究其在磷胁迫下的潜在光合速率。实验结果表明:在磷胁迫条件下,叶绿素a、叶绿素b、总叶绿素含量以及叶绿素a与叶绿素b的比值均下降,叶片中总氮含量和可溶性蛋白含量也下降。尽管叶绿素荧光参数变化没有规律性,但水曲柳幼苗在磷胁迫下的潜在光合速率却随磷供给水平的下降而下降。潜在光合速率的下降与叶片氮向Rubisco中的分配有关。

Change of Potential Photosynthesis Rates in Fraxinus Mandshurica Seedlings Supplied with Different Phosphorus Levels

Phosphorus stress is often an environmental stress for forest trees.The properties in morphology and physiology of forest trees change greatly.In this paper,we used one-year old Fraxinus mandshurica seedlings as experimental material to study changes of potential photosynthesis rates of these seedlings under phosphorus stress.The results showed that the contents of chlorophyll a and b,total chlorophyll levels,and ratios of chlorophyll a to chlorophyll b reduced when these seedlings were under phosphorus stress.At the same time,total nitrogen contents and soluble protein contents in leaves of seedlings under phosphorus stress reduced.Although parameters of chlorophyll a fluorescence changed irregularly,the potential photosynthesis rates reduced as phosphorus levels supplied to the seedlings decreased.The reduce of potential photosynthesis rate is related to the partitioning of nitrogen in leaves to Rubisco.