[Effects of low temperature and weak light on the functions of photosystem in Prunus armeniaca L. leaves in solar greenhouse].
In this paper, the net photosynthetic rate (Pn), actual photochemical efficiency of PS II (PhiPSII), photochemical quenching (qp), and maximal photochemical efficiency of PS II in light (Fv'/Fm') of apricot (Prunus armeniaca) leaves in solar greenhouse were measured, and the effects of low temperature (7 degrees C) and weak light (200 micromol x m(-2) x s(-1) PFD) on the photoinhibition of PS I and PS II were investigated. The results showed that the optimal temperature for the photosynthesis of apricot leaves was around 25 degrees C, and the photosynthetic capacity was reduced greatly by the low temperature and weak light, inducing a markedly increased excitation press (1-qp) and in turn, resulting in photoinhibition. The functions of both PS I and PS II were damaged by the low temperature and weak light. Comparing with those only subjected to low temperature, the leaves subjected to both low temperature and weak light had a decreased activity of PS I, with a decrement of 28.26% within 2 h, but their maximal photochemical effeciency of PS II (Fv/Fm) had little change in the same period, suggesting that under low temperature and weak light, PS I was more suffered from photoinhibition than PS II.
Shandong Institute of Pomology, Tai'an 271000, Shandong, China. sunshan@sdip.cn
Shan
S
Sun
Li-tao
LT
Zhang
Jia-Xi
JX
Wang
Shao-Min
SM
Wang
Hua-Jun
HJ
Gao
Hui-Yuan
HY
Gao
D000383:Agriculture / Q000379:methods; D004780:Environment, Controlled; D010788:Photosynthesis / Q000502:physiology / Q000528:radiation effects*; D018515:Plant Leaves / Q000502:physiology*; D027861:Prunus / Q000502:physiology*; D013472:Sunlight; D013696:Temperature