摘要
光合作用与干物质生产是观赏植物外观品质形成的基础。水分是影响植物光合作用与干物质生产的重要因子。为定量研究水分对切花百合光合作用与干物质生产的影响,以切花百合品种‘索邦’(Lilium‘Sorbonne’)为试验材料,于2009年3月至2010年1月在南京的连栋温室内开展了不同定植期和不同水分处理的栽培试验,以基于光温的温室花卉生长动态预测模型为基础,定量分析了不同定植期和不同水分处理条件下切花百合叶面积指数、光合速率和干物质生产的动态影响,并确定了切花百合正常生长的临界基质水势,建立了基质水势对切花百合光合速率和干物质生产影响的动态预测模型。结果表明,本文所建模型对切花百合叶片最大总光合速率和植株总干质量的预测效果较好,模型对叶面积指数、叶片最大总光合速率和植株干物质量的预测值与实测值之间的决定系数(r2)分别为0.97,0.96,0.94,相对根均方差(rRMSE)分别为7.12%、4.37%、11.14%。该模型能较好地预测水分对切花百合叶片最大总光合速率和植株总干质量的动态影响,可为进一步优化切花百合生产的水分管理提供决策支持。
Photosynthesis and dry matter production are essential for guaranteeing the external quality of ornamental plants. Water is the important factor affecting plant photosynthesis and dry matter production. The aim of this study was to quantitatively investigate the effects of water on photosynthesis and dry matter production of Lilium. For this purpose, experiments of Lilium ＇ Sorbonne ＇ with three planting dates and four levels of water treatment were conducted in a greenhouse in Naijing from March 2009 to January 2010. During each planting date, the four levels of water treatment were, respectively, -4---10 kPa, -10---15 kPa, -15---25 kPa and -25---40 kPa. The plot of an area of 0.8 m2 for each water treatment with three replicas was arranged in a randomized block design. In each water treatment, substrate water potential at 0.1 m below the substrate surface was monitored using tension meters （with 3 replicas）. When the substrate water potential reached its designed lower limit value, the crops were irrigated until reaching the designed upper limit value. Substrate water potential at O. 1 m below the substrate surface and the corresponding gravimetric soil water content were measured to establish the substrate water potential and gravimetric water content relationship curve. This curve was then used to determine the amount of water required for irrigation in each treatment. Photosynthetically active radiation and air temperature above the canopy inside the greenhouse were monitored automatically every 10 s and the half-hourly averaged data were recorded using a datalogger （CR1000; Campbell Scientific Inc. ）. During each experiment, leaf net photosynthesis rate of the lst--3th leaves （ counting from the top downward） were measured using the photosynthesis system （LI-COR 6400; LI-COR Inc）, and 3 plants in each plot were sampled to measured leaf area index and plant dry weight at different development stages. Based on the experimental data, effects of substrate water potential on the dynamics of leaf photosynthesis rate and leaf area index were quantified. These quantitative relationships were then integrated into a photosynthetically driven dry matter production model to predict the effects of substrate water potential on dry matter production of cut lily. Independent experimental data were used to validate the model. The results showed that leaf photosynthesis rate, leaf area index and plant dry matter production decreased significantly when substrate water potential is below -15 kPa. Therfore, the critical substrate water potential for the normal growth of cut lily was determined as -15 kPa. Comparison between the simulated and measured results showed that the coefficient of determination （r2） between the simulated and the measured values of leaf area index, the maximal leaf gross photosynthesis rate and the dry matter mass were 0.97, 0.96, 0.94, respectively ; and the relative root mean square error （ rRMSE ） between the simulated and the measured values of leaf area index, the maximal leaf gross photosynthesis rate and the dry matter mass were 7. 12%, 4. 37% , 11.14% , respectively. The model developed in this study gives satisfactory predictions of the maximal leaf gross photosynthesis rate and the dry matter production of cut lily, hence, can be used for optimizing water management for cut lily production.
出处
《生态学报》
CAS
CSCD
北大核心
2012年第17期5387-5395,共9页
Acta Ecologica Sinica
基金
国家自然科学基金项目(4975070)
公益性行业(气象)科研专项经费项目(GYHY200906023)
国家科技支撑计划(2006BAD07B05)
内蒙古民族大学博士科研启动基金(BS261)
关键词
切花百合
基质水势
干物质生产
模型
cut lily
substrate water potential
dry matter production
model
