环境因子耦合对温室番茄生长及光合作用的调控效应

Regulating Effect of Environmental Factors Coupling on Tomato Growth and Photosynthesis in Greenhouse

为解析环境因子耦合对番茄光合作用及生长的驱动和调控作用,实现温室番茄生长环境精准管理。对温室内空气温度、相对湿度、光合有效辐射采用二次正交旋转设计组合,分析环境多因子耦合对结果期番茄生长及光合作用调控效应。以番茄相对生长速率和净光合速率综合最优为评价目标,建立生长光合复合评价指标对环境多因子的综合响应模型。结果表明:环境多因子对番茄相对生长速率、净光合速率的调控效应和路径不同。单因子效应分析表明空气温度、相对湿度与相对生长速率关系均为开口向上抛物线,但与净光合速率关系均为开口向下抛物线。边际效应分析表明,对相对生长速率,3种环境因子均为正效应;对净光合速率,空气温度、相对湿度为负效应,光合有效辐射为正效应。通径分析表明,相对生长速率的主控因子为叶绿素含量、净光合速率,受环境因子的间接调控;净光合速率的主控因子为植株含水量,叶绿素含量,受环境因子的直接调控。生长光合复合指标响应模型中,温度与湿度、温度与光照均存在显著负交互作用,表明光照强或湿度大时提高空气温度会抑制番茄生长。综合考虑番茄生长及光合作用,秋冬及早春季节温室结果期番茄最适生长环境为温度29.2℃,湿度75%,光照400μmol·m^-2·s^-1。

The aim of this experiment is to analyzethe drivingand regulating effects of environmental factors coupling on tomato growth and photosynthesis, so that the management of greenhouse environment for tomato growth can be more suitable. Based on the experimental factors like air temperature, relative humidity andsolar radiation, a composite quadratic orthogonal regressive rotation design of three factors and five levelswas adopted to characterize the environmental factors coupling in driving and regulating tomato photosynthesis and growth. Considering the comprehensive growth of greenhouse tomato, an optimizedmodel was established based on the response both net photosynthetic rate and relative growth rate to environmental factors. Results showed there were different inregulating effectand approachesof environmental factors on relative growth rate and net photosynthetic rateto tomato. Single-factor effects of air temperature and relative humidity on relative growth rate are both open upward parabolic,butopen downwards parabola on net photosynthetic rate. Themarginal effectsofthree environmental factors on the relative growth rate are allpositive, while the negative effectswere found in air temperature and relative humidityon net photosynthetic rate.The path analysis revealed that the main-control factors for relative growth rate were stomatal conductance and transpiration rate,which was indirectly regulated by environmental factors;and the main-control factors fornet photosynthetic rate were plant water content and stomatal conductance, which wasregulated by environmental factors directly. There are significant negative interactions between temperature and humidity, in the response model of growth and photosynthetic composite indicators, also between temperature and light. Thus, increasing the air temperature would inhibit growth when tomato in strong light or high humidity condition. Considering both growth and photosynthesis of tomato, the optimal environment combinations of temperature, relative humidity and photosynthetically active radiation(PAR)were 25℃, 83.9% and 400μmol·m^-2·s^-1 for the fruiting periodin autumn winter and early spring.