[关键词]
[摘要]
目的解决浙江雪胆栽培中的水分需求问题。方法对浙江雪胆进行不同天数干旱处理,测定叶绿素的量、气体交换和叶绿素荧光参数。结果随着土壤相对含水量的下降,净光合速率(Pn)先迅速上升,15d后开始下降,气孔导度(Gs)和蒸腾速率(E)也在胁迫5d后均有明显的下降,但是胞间CO2浓度(Ci)却明显上升,开放光系统Ⅱ(PSⅡ)反应中心激发能捕获效率(Fv'/Fm')也并没有发生明显的变化,电子传递速率(ETR)、PSⅡ实际量子产额(ΦPSⅡ)、光化学猝灭(qP)和非光化学猝灭(NPQ)则是先上升后下降,与Pn变化一致。结论轻度干旱有利于浙江雪胆的生长,这主要与轻度干旱条件下能有效地耗散过剩的激发能有关。
[Key word]
[Abstract]
Objective To investigate the requirement of water in Hemsleya zhejiangensis during the culture process.Methods The chlorophyll content, the gas exchange, and chlorophyll fluorescence parameter in H. zhejiangensis were measured after treatment with drought stress for different time.Results With decreasing of relative soil water content, the net photosynthetic rate (Pn) in H. zhejiangensis was increased before the 15 d and than was decreased. The stomatal conductance (Gs) and transpiration rate (E) were decreased under drought stress for 5 d, while the intercellular CO2 concentration (Ci) was increased. The efficiency of energy conversion of open PSⅡ (Fv'/Fm') maintained rather stable, while its electron transport rate (ETR), actual PSⅡ efficiency (ΦPSⅡ), photochemical quenching (qP), and non-photochemical quenching (NPQ) were increased after the 10 d of drought stress, and then was decreased, which was consistent with the change in Pn.Clousion The growth of H. zhejiangensis is promoted under slight drought stress condition, which is probably associated with the dissipation of excess light energy.
[中图分类号]
[基金项目]
浙江省教育厅基金资助项目(20040702)