摘要
采用一种负水头供水控水盆栽装置,通过设定不同供水吸力(1、3、5、7、9、11、13kPa)来控制不同土壤含水量,研究土壤水分对黄瓜光合、荧光参数的变化及根系生长的影响.结果表明:供水吸力与土壤含水量呈反比对应关系,各处理控制的土壤含水量范围为14.23%～42.32%;随供水吸力的增强,不同生育时期黄瓜叶片净光合速率都呈抛物线变化趋势,初花期7～11kPa处理和采收期3～5kPa处理叶片的净光合速率较强,采收期9～13kPa的高供水吸力处理叶片净光合速率较低是由气孔限制因素导致的,而1～5kPa低供水处理下叶片PSⅡ光量子转化成化学能的效率较高,实际光化学效率较高,光抑制发生的可能性较低;不同生育时期叶片叶绿素含量和蒸腾速率与净光合速率呈明显的正相关关系;随供水吸力的增强,黄瓜根系生长及活力呈抛物线变化趋势,5kPa处理的根系活力最高,7kPa处理的根系干物质量最大.说明3～7kPa的供水吸力处理更有利于温室黄瓜根系生长与叶片净光合速率的提高.
To study the effects of soil water content on the photosynthesis,fluorescence parameters,and root growth of greenhouse cucumber （Cucumis sativus L.）,a pot experiment was conducted,using a negative pressure water supplying and controlling device to control soil moisture regime.Seven levels of water supply tension （WST）,i.e.,1,3,5,7,9,11,and 13 kPa,were designed.The WST was inversely proportional to soil water content,and the gravimetric soil water content was maintained in the range of 14.23%-42.32%.With increasing WST,the leaf net photosynthetic rate （Pn） in different growth periods showed a parabolic trend,being higher when the WST was 7-11 kPa at initial flowering stage,and was 3-5 kPa at fruiting stage.The reason for the decreased Pn at 9-13 kPa WST was stomatal limitation.Under 1-5 kPa WST,the actual photochemical efficiency （ΦPSⅡ） had a high value,and the possibility of photo inhibition was small.Both the leaf transpiration rate and the chlorophyll content were positively correlated with leaf Pn in different growth periods.Root growth and activity also had a parabolic trend with increasing WST.The maximum root dry mass and root activity happened at 7 kPa and 5 kPa WST,respectively.Our results indicated that a WST of 3-7 kPa was more profitable for the leaf photosynthesis and root growth of greenhouse cucumber.
出处
《应用生态学报》
CAS
CSCD
北大核心
2010年第1期67-73,共7页
Chinese Journal of Applied Ecology
基金
北京市农业科技示范推广项目
扬州大学研究生培养创新工程项目资助
关键词
负水头控水
光合特性
荧光特性
根系活力
黄瓜
negative pressure water control
photosynthetic characteristics
fluorescence characteristics
root activity
cucumber.
