摘要
在25℃空气条件下,在低光强(136μE·m^(-2)·s^(-1))照光2小时的初期,倒3叶的光合速率保持相对较高的稳定速度,以后慢慢下降;而刚定长的剑叶和己衰老的倒5叶,在上述时间内却保持较低的光合速率且没有明显变化。在高光强(1680μE,m^(-2)·S^(-1))下,功能叶和剑叶的光合速率从较高水平上迅速下降,约80分钟后下降到零,以后逐渐恢复。衰老叶的光合速率下降较为缓慢,约在90分钟时下降到零,在以后的50分钟内,未见到光合速率的恢复。在低光强(136μE·m^(-2)·s^(-1))下,12℃和40℃都未见到光合抑制。在高光强(1680μE·m^(-2)·s^(-1))下,光合抑制则与温度有关。对防御光抑光合的酶活性和物质含量变化也进行了观察。
Effect of light and temperature on photoinhibition of photosynthesis was investigated, using rice leaves of differental physiologial ages. At 25℃ in normal air, it was found that the response of the third leaf ( counted downward from the flag leaf ) was quite different from those of others leaves. In low light intensity ( 136μE.m-2.s-1 ) ,during initial period of the 2 h illumination, Photosynthetic rate of the third leaf maintained at a high and stable level, and then dropped slowly. The flag leaf just at full expansion stage and the senescented leaf showed lower photosynthetic rate and did not show marked changes in the 2 h period. In high light intensity ( 1680 μE.m-2.S-1 ) ,however, the photosynthetic rate of the flag leaf and third leaf decreased rapidly from the higher lavel until zero in 80 minutes. A gradual recovery was found later. For the senescent leaves the photosyn thetic rate decreased slowly to zero in 90 minutes, but no recovery was found in 50 minutes.
No photoinhibition was observed in low light intensity (136 μE.m-2.s-1) both at 12℃ and 40℃. In high light intensity (1680 μE.m-2.s-1), photoinhibition was related to temperatures. At 25℃, no apparent photoinhibition was observed, whereas at 12℃ and at 40℃ with high light, photoinhibition was very obvious.
Rice varieties less sensitive to photoinhibition usually showed a marked reduction in superoxide dismutase (SOD) and catalase (CAT) activities after exposing to high light intensity at 40℃ for 1 h, while ascorbic acid (ASA) content increased more than in sensitive varieties. A similar relation wa s observed in leaves of different ages which responded differently to photoinhibition.
出处
《江苏农业学报》
CSCD
1989年第1期1-10,共10页
Jiangsu Journal of Agricultural Sciences
关键词
水稻
光抑制
光合作用
梅
抗坏血酸
Rice
Photoinhibition
Photosynthesis
Superoxide
dismutase
Catalase
Ascorbic acid
