摘要
在大田栽培条件下研究不同程度遮荫对凤丹白光合特性和叶绿素荧光参数的影响。2a数据表明:夏季晴天、自然光照条件下,凤丹白的光合速率日变化为"双峰型",有明显的"光合午休"现象;遮荫75%条件下,净光合速率没有出现"光合午休"现象。经过连续2a遮荫后,遮荫75%条件下的净光合速率显著低于其他处理,净光合速率在一天中始终处于最低水平;遮荫45%和60%条件下的净光合速率在一天中保持较高。随着遮荫程度增加,最大净光合速率、光补偿点、光饱和点降低。经过遮荫处理的Fv/Fm均显著高于全光照植株。结果表明,夏季大田中午强光、高温条件下,凤丹白光合作用的光抑制显著,遮荫叶片优于全光照叶片,适度遮荫提高了光合效率,综合比较各参数可知,遮荫45%~60%最适合凤丹白的生长。
A 2-year-long investigation was carried out on the effects of shading treatment on the photosyn- thetic characters and the chlorophyll fluorescence parameters of Paeonia ostii cv.‘Phoenix White’ in the field. In sunny day in summer, under natural fully sunshining treatment, the diurnal variation of the net photosynthetic rate （Pn） demonstrated a two-peak curve with midday depression of photosynthesis, no midday depression was observed under 75% shading treatment,in which Pn maintained lower levels all day than the other treatments. However,Pn maintained higher levels all day under 45% and 60% shading treat- ments. The maximum Pn, the light compensation point, and the light saturation decreased with the increase of shading degree. Through shading treatment, the value of Fv/Fm was significantly higher than that of fully sunshining treatment. These results demonstrated that moderate shading could alleviate the photo damage of PS II reaction center and then improve the total photosynthetic efficiency under strong midday light in the field. Shading treatment in summer could improve photosynthetic function. It was concluded that P. ostii would grow well under 45%--60% shading treatment.
出处
《西北林学院学报》
CSCD
北大核心
2017年第5期46-51,共6页
Journal of Northwest Forestry University
基金
国家农业综合开发名优经济林"河南省林科院油用牡丹示范项目"([2015]23号)
河南省产学研合作计划项目"油用牡丹苗木产业化开发与示范"(132107000043)
关键词
凤丹白
遮荫
光合特性
荧光参数
Paeonia ostii cv. ‘Phoenix White’
shading
photosynthetic characteristic
chlorophyll fluores-cence parameter
