中国物理B ›› 2003, Vol. 12 ›› Issue (10): 1159-1165.doi: 10.1088/1009-1963/12/10/319
任兆玉1, 侯洵2, 辛越勇3, 许晓明4, 王水才5, 贺俊芳5
Ren Zhao-Yu (任兆玉)a, Xu Xiao-Ming (许晓明)b, Wang Shui-Cai (王水才)c, Xin Yue-Yong (辛越勇)d, He Jun-Fang (贺俊芳)c, Hou Xun (侯洵)ac
摘要: A high yielding rice variety mutant (Oryza sativa L., Zhenhui 249) with low chlorophyll b (Chl b) has been discovered in natural fields. It has a quality character controlled by a pair of recessive genes (nuclear gene). The partial loss of Chl b in content affects the efficiency of light harvest in a light harvest complex (LHC), thus producing the difference of the exciting energy transfer and the efficiency of photochemistry conversion between the mutant and wild-type rice in photosynthetic unit. The efficiency of utilizing light energy is higher in the mutant than that in the wild-type rice relatively. For further discussion of the above-mentioned difference and learning about the mechanism of the increase in the photochemical efficiency of the mutant, the pico-second resolution fluorescence spectrum measurement with delay-frame-scanning single photon counting technique is adopted. Thylakoid membranes of the mutant and the wild-type rice are excited by an Ar^+ laser with a pulse width of 120 ps, repetition rate of 4 MHz and wavelength of 514 nm. Compared with the time and spectrum property of exciting fluorescence, conclusions of those ultrafast dynamic experiments are: 1) The speeds of the exciting energy transferred in photo-system I are faster than that in photo-system II in both samples. 2) The speeds of the exciting energy transfer of mutant sample are faster than those of the wild-type. This might be one of the major reasons why the efficiency of photosynthesis is higher in mutant than that in the wild-type rice.
中图分类号: (Photochemistry)