摘要
夏蜡梅是浙江省特有的濒危单种属物种.本文研究了不同程度土壤水分胁迫和不同温度处理对2年生盆栽夏蜡梅光合作用的影响.结果表明:轻度和中度水分胁迫下夏蜡梅净光合速率分别下降至对照的92.3%和74.3%,净光合速率的降低主要由气孔限制引起;重度水分胁迫下,净光合速率仅为对照的44.4%,主要由非气孔限制引起.夏季夏蜡梅的光合适宜温度范围在20℃～28℃,39℃下其净光合速率、水分利用效率和最大光化学效率显著降低,暗呼吸速率和蒸腾速率显著升高.随着水分胁迫的加重及处理温度的升高,夏蜡梅光补偿点上升,光饱和点、表观量子效率和最大净光合速率下降.重度水分胁迫及高温是制约夏蜡梅生存的重要环境因子.
Sinocalycanthus chinensis is an endangered species in Sinocalycanthus, and only distributed in Zhejiang Province of China. This paper studied the photosynthetic responses of 2-year-old pot-cultured S. chinensis to different levels of water stress and temperature. The results indicated that under mild and moderate water stress, the net photosynthetic rate （Pn） of S. chinensis leaves was decreased to 92.3% and 74.3% of the control, respectively, which was mainly attributed to stomatal limitation; and under severe water stress, the P, was decreased to 44.4% of the control, which might be mainly linked to non-stomatal limitation. The appropriate temperature for S. chinensis photosynthesis was from 20 ℃ to 28 ℃. At 39 ℃ , the Pn, water use efficiency （WUE） , and maximal photochemistry efficiency （Fv/Fm ） were decreased significantly, while the dark respiration rate （ Rd ） and transpiration rate （ Tr） were enhanced significantly. With increasing water stress and temperature, some photosynthetic parameters including light saturation point （LSP）, apparent quantum yield （AQY） and maximal CO2 assimilation rate （Pmax） decreased to certain extents, while light compensation point （LCP） increased, suggesting that both severe water stress and higher temperature were the important environmental factors affecting the survival of S. chinensis.
出处
《应用生态学报》
CAS
CSCD
北大核心
2008年第1期43-49,共7页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(39870160)
浙江省自然科学基金资助项目(Y504220).
关键词
水分胁迫
光合特性
气体交换
叶绿素荧光
夏蜡梅
water stress
photosynthetic characteristics
gas exchange
chlorophyll fluorescence
Sinocalycanthus chinensis.
