【摘要】 田间生姜的光呼吸速率（Ｐｒ） 随光强的增加而升高，随季节和生长期的进展而降低，其日变化进程基本与ＰＦＤ 同步，峰值一般出现在１０ ：００ ～１２：００ ；遮荫可明显降低Ｐｒ。用Ｐｒ 抑制剂抑制Ｐｒ 后光抑制加重，光化学效率和光合速率降低。叶黄素循环的关键组分—玉米黄质（Ｚ） 及叶黄素循环库（Ａ＋ Ｚ＋ Ｖ） 的含量随光强的增加而增加，也随季节而变化，其含量是１４／８ ＞ ２９／９ ＞ １／７，日变化与ＰＦＤ 的日变化相呼应，峰值一般出现在１２：００ 前后；遮荫可明显降低中午前后的Ａ＋ Ｚ＋ Ｖ 及Ａ＋ Ｚ的含量，说明Ｐｒ 和叶黄素循环的关键组分在午间强光下升高，可排散叶片吸收的过多能量，防御光抑制对叶片光合机构的破坏更多还原

【Abstract】 Using a HPLG and a portable ADC photosynthetic gas analysis system, we observed the seasonal and diurnal changes of photorespiration (Pr) and xanthophyll (L) cycle in ginger leaves under field conditions so as to understand the role of L and Pr in defending leaves against photoinhibitory damage. The results were as follows: the seasonal and diurnal changes of Pr and L of ginger leaves were marked, Pr in 14, August was higher than that in 29, September. Pr showed a diurnal change in response to PFD, and its peak was around 10:00～12:00. Pr declined with increasing shade extent. The L cycle showed a diurnal variation in response to PFD, xanthophyll cycle pool (A+Z+V) and its key component (A+Z) increased during mid day period, and its peak was around 12:00. The content of A+Z and the size of xanthophyll cycle pool in different months showed a trend of 14/8>29/9>1/7.The content of A+Z+V and A+Z reduced as increase of shade.The above results illustrated that Pr and xanthophyll cycle had a positive role in dissipating excessive light energy and in protecting photosynthetic apparatus of ginger leaves from mid day high light stress.更多还原