[Effects of groundwater level on chlorophyll fluorescence characteristics of Tamarix hispida in lower reaches of Tarim River].
Based on the monitoring data of groundwater level at the typical sections in lower reaches of Tarim River, three survey plots nearby the ecological monitoring wells with groundwater depths > 6 m were selected to investigate the chlorophyll fluorescence characteristics of Tamarix hispida and its photosynthetic activity of PSII under effects of different groundwater depths. With increasing groundwater depth, the chlorophyll fluorescence parameters such as actual photochemical efficiency of PSII in the light (phi(PSII)), electron transport rate (ETR), and photochemistry quenching (q(p)) of T. hispida decreased, while the non-photochemistry quenching (q(N), NPQ) and the yield for dissipation by down-regulation (Y(NPQ)) increased remarkably, and the maximal photochemical efficiency of PSII (Fv/Fm) maintained an optimum value. All the results suggested that the PSII photosynthetic activity of T. hispida under drought stress declined with increasing groundwater depth, and the greater excess energy could result in more risk of photo-inhibition. However, the good adaptability and drought tolerance of T. hispida could make its PSII not seriously damaged, though the drought stress actually existed.
Zhu
Cheng-gang
CG
Key Laboratory of Oasis Ecology and Desert Environment, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China. zcg197614@sina.com
Li
Wei-hong
WH
Ma
Jian-xin
JX
Ma
Xiao-dong
XD
D000222:Adaptation, Physiological; D002734:Chlorophyll / Q000032:analysis; D055864:Droughts; D017753:Ecosystem; D004784:Environmental Monitoring; D005453:Fluorescence; D045332:Photosystem II Protein Complex / Q000502:physiology*; D045483:Rivers; D032363:Tamaricaceae / Q000378:metabolism / Q000502:physiology*; D014867:Water / Q000502:physiology*
D045332:Photosystem II Protein Complex; D014867:Water; D002734:Chlorophyll