[Effects of low temperature- and weak light stress and its recovery on the photosynthesis and chlorophyll fluorescence parameters of cut flower chrysanthemum].
The cut flower chrysanthemum 'Jinba' was respectively treated with lower temperature and weaker light (16 degrees C/ 12 degrees C, PFD 100 micromol x m(-2) x s(-1)) and critical low temperature and weak light (12 degrees C/8 degrees C, PFD 60 micromol x m(-2) x s(-1)) for 11 days, and then transferred to normal condition (22 degrees C/18 degrees C, PFD 450 micromol x m(-2) x s(-1)) for 11 days, aimed to study the low temperature- and weak light stress and its recovery on the photosynthesis and chlorophyll fluorescence of chrysanthemum leaves. Under the stress of lower temperature and weaker light, the net photosynthetic rate (P(n)) and stomatal limitation (L(s)) of chrysanthemum leaves decreased while the intercellular CO2 concentration (C(i)) increased, the maximal photochemical efficiency of PS II (F(v)/F(m)) in dark and the initial fluorescence (F(o)) had no obvious change, but the maximal photochemical efficiency of PS II (F(v)'/F(m)') in light increased after an initial decrease. Contrarily, under the stress of critical low temperature and weak light, the F(o) increased, and the F(v)/F(m) and F(v)'/F(m)' decreased significantly. The quantum yield of PS II electron transport (phi(PS II)), photochemical quenching (q(p)), and apparent photosynthetic electron transfer rate (ETR) of chrysanthemum leaves decreased with increasing stress and time, and recovered quickly after the release of lower temperature- and weaker light stress but more slowly after the release of critical low temperature- and weak light stress. At the same time, the photochemistry react rate (Prate) decreased, but the hot dissipation of antenna (Drate) and the energy dissipation of PS II (Ex) increased under the stress conditions. Drate was the main pathway of superfluous light allocation.
Liang
Fang
F
State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai' an 271018, Shandong, China. if5460@163.com
Zheng
Cheng-Shu
CS
Sun
Xian-Zhi
XZ
Wang
Wen-Li
WL
D002734:Chlorophyll / Q000032:analysis; D031202:Chrysanthemum / Q000502:physiology*; D003080:Cold Temperature; D035264:Flowers / Q000502:physiology; D008027:Light; D010788:Photosynthesis / Q000502:physiology*; D045332:Photosystem II Protein Complex / Q000032:analysis*; D013312:Stress, Physiological
D045332:Photosystem II Protein Complex; D002734:Chlorophyll