红提葡萄光合速率和气孔导度的光响应特征

摘要

为了比较几种常用的光响应模型和气孔导度模型对红提葡萄的适用性,利用LC pro+便携式光合仪,测定了大田土壤水分状况良好情况下果粒膨大期和浆果成熟期篱架红提葡萄对光强的响应过程.采用常用的光响应模型(非直角双曲线模型、直角双曲线修正模型)和气孔导度模型(Bll-Barry模型、气孔导度机理模型)对光合速率及气孔导度进行拟合,同时将气孔导度Ball-Bary模型与光合速率的光响应非直角双曲线模型进行耦合,并与Jarvis模型进行比较,分析了红提葡萄气孔导度的光响应特征.结果表明:非直角双曲线模型和直角双曲线修正模型均可较好地拟合红提葡萄光合速率光响应过程,但通过非直角双曲线模型获得的初始量子效率(口)、暗呼吸速率(Rd)、光补偿点(LCP)与实测值更接近,拟合效果更佳(R2 ≥0.987);气孔导度随光合速率的增大而增大,应用Ball-Barry模型拟合该过程得到的决定系数较大(R2≥0.715),均方根误差较小(RMSE≤0.0127),较气孔导度机理模型能更好地拟合红提葡萄气孔导度与光合速率的关系;构建的Ball-Bary模型与非直角双凿线的耦合模型整体上可以描述气孔导度对光强的响应(R2≥0.703),但拟合高光强下气孔导度精度较低,与耦合模型相比,Jarvis模型模拟值与实测值更加接近(R2≥0.839),且均方根误差最小(RMSE≤0.0106),说明Jarvis模型拟合效果优于耦合模型.研究结果可为定量分析葡萄叶片气孔调节行为和计算光合生产力提供理论依据.%In order to access the applicability of light response model and stomatal conductance model for Red Globe Grape,the light response processes of red globe grape were measured at fruit swelling stage and berry ripening stage in the field.The optical light response model (non rectangular hyperbola model,modified rectangular hyperbola model) and stomatal conductance model (Ball-Barry model,stomatal conduction mechanism model) were adopted to fit photosynthetic rate and stomatal conductance.Meanwhile,Ball-Barry model was coupled with non rectangular hyperbola model and compared with Jarvis model,and then the stomatal conductance of the light response characteristics was analyzed.Results indicated that the non rectangular hyperbolic model and the modified rectangular hyperboh model could predict the light response process of photosynthetic rate of red globe grape well.The initial quantum efficiency (α),dark respiration rate (Rd) and light compensation point (LCP) obtained by non rectangular hyperbolic model were more close to the measured values,the determination coefficient was larger than 0.9 (R2≥ 0.987).Furthermore,the stomatal conductance increased with the increase of photosynthetic rate,the determination coefficient fitted by Ball-Barry model was bigger(R2≥0.715),and the RMSE was smaller(RMSE≤O.O127),which indicated that Ball-Barry model could better predict the relationship between the stomatal conductance and photosynthetic rate of red globe grape.Coupling model could describe the light response of stomatal conductance (R2 ≥ 0.703) as a whole,but the accuracy of stomatal conductance under the high light intensity was low.Different from the coupling model,the simulated results from the Jarvis model were more close to the measured data (R2≥0.839),and the value of RMSE was small (RMSE ≤0.0106),which suggested that the Jarvis model was more superior than the coupled model in describing the light response of stomatal conductance of red globe grape.Results obtained above could provide theoretical basis for the quantitative analysis of the stomatal regulation behavior of grape leaves and the calculation of photosynthetic productivity.