水分对温室盆栽番茄叶片光响应特性的影响

Effect of water on characteristics of light response of tomato leaves in greenhouse

【目的】探讨水分对番茄叶片光响应特性的影响,为番茄栽培提供科学用水依据。【方法】以番茄品种"金棚1号"为材料,采用盆栽方式,分别按照单株日蒸腾蒸发量(ET)的50%,75%,100%和125%作为补充灌溉量设置4个水分处理,并利用Li-6400XT便携式光合仪测定番茄叶片的光响应曲线。【结果】随着灌溉量的增加,番茄叶片的净光合速率(Pn)、最大光合速率(Pmax)、光饱和点(LSP)、蒸腾速率(Tr)、胞间CO2浓度(Ci)、气孔导度(Gs)均呈现出增加的趋势,其中以125%ET处理的最高;水分利用效率(WUE)、叶片饱和水汽压亏缺(Vpdl)、叶片温度(Tl)、气孔限制值(Ls)则呈下降趋势,其中以50%ET处理的最低;表观量子效率(α)、光补偿点(LCP)则呈先上升后下降的趋势。随着光合有效辐射强度(PAR)的增加,番茄叶片的Pn、Tr、Gs、WUE、Ls均呈先迅速升高后缓慢升高甚至下降的趋势;Ci先急剧下降,后基本保持平稳;Vpdl和Tl先略有下降后逐渐上升。【结论】气孔限制因素是水分影响番茄叶片光合作用的主要因素。按照ET的125%补充灌溉量,可明显提高番茄叶片的Pn,降低WUE。

【Objective】In order to provide basis for theoretical water management of tomato cultivation,the effect of water on characteristics of light response of tomato leaves was discussed.【Method】With tomato ＂Jinpeng No.1＂ as the experimental materials,and under the different water supplementary irrigation treatments of 50%,75%,100% and 125% of evapotranspiration for plant,the light response characteristics of tomato leaves were measured by Li-6400XT.【Result】With the increase of irrigation amount,net photosynthetic rate（Pn）,light-saturated photosynthetic rate（Pmax）,light saturation point（LSP）,transpiration rate（Tr）,intercelluar CO2 concentration（Ci） and stomatal conductance（Gs） of tomato leaves all rose,and they were the highest under the supplementary irrigation treatment at 125% of evapotranspiration.While water use efficiency（WUE）,leaf vapor pressure deficit（Vpdl）,leaf temperature（Tl）,stomatal limitation value（Ls） decreased,under the supplementary irrigation treatment at 50% of evapotranspiration,they were the lowest.At the same time,apparent quantum yield（α） and light compensation point（LCP） increased first and then decreased.With the increase of photosynthesis active radiation（PAR）,Pn,Tr,Gs,WUE and Ls all rose rapidly first and then slowly decreased,and Ci fell sharply and then decreased slowly.While Vpdl and Tl decreased slightly and then increased steadily.【Conclusion】Stomatal limiting factor was the main factor influencing photosynthesis of tomato leaves.Supplementary irrigation of 125% of evapotranspiration for plant improved Pn significantly but decreased WUE.