昼夜温差对设施番茄品质形成的调控机理及数值模拟

Tomato（Solanum lycopersicum）is the main facility crop in China. The outstanding problems in greenhouse tomato production are low yield per unit, poor quality and difficult to conduct year-round production. The temperature difference between day and night (DIF) will be the key factor to affect the quality formation of tomato if the daily mean temperature and light intensity is constant. However, so far, the influencing mechanism of DIF on tomato quality and the quantitative relationship between the two are still unclear. According to the response of tomato quality formation to DIF, an environment-controlled experiment will be carried out in this study, in which, a tomato varity named "jinguan 5" will be selected as the material and, many eco-physiological index of tomato, such as RuBP enzyme activity, leaf-gas exchange, fluorescence parameters, sink-strength characters and fruit nutrients will be measured and analyzed under different DIF tratements. The goal of this study is to explain the influencing mechanism of DIF on tomato growth and quality. Meanwhile,the response mechanisms of development process, canopy structure, source-sink relation and quality formation of tomato on DIF will be analyzed, and the key parameters needed to run the facility tomato model will also be extracted. Accordingly,the response mechanisms of development process，canopy structure, source-sink relation and quality formation of tomato on DIF will be analyzed, and the key parameters needed to modelling the facility tomato will also be extracted. On the basis of crop growth models developed by the applicants,a set of greenhouse meteorological and crop data will be used as the input to develop a simulation model based on the response of the tomato quality to DIF, with a view to dynamically predicting harvest, yield and quality of greenhouse tomato crop. Finally, the microclimate index system of environmental regulation for tomato year-round production will be proposed. The results of this study could provide a scientific basis for quality regulation of greehouse tomato crop.

番茄是中国主要的设施作物。设施番茄生产中的突出问题是：单产低、品质差、难以周年生产。当日均温度和光强恒定时，昼夜温差是影响番茄品质形成的关键因素，但有关昼夜温差对番茄品质的影响机理及两者间的定量关系至今尚不清楚。本研究根据番茄品质形成对昼夜温差的响应，拟开展环境控制试验，以番茄品种'金冠五号'为试材，通过测定和分析不同昼夜温差处理下番茄的生理生态指标，包括RuBP酶活性、叶气交换、荧光参数、库强特征和果实成分等，试图阐明昼夜温差对番茄生长发育和品质形成的影响机理。据此，分析番茄发育进程、冠层结构、源库动态和品质形成对昼夜温差的响应机制，提取建模所需的关键参数。再利用温室气象和作物数据，在自行研制的设施作物模型基础上，构建基于昼夜温差响应的设施番茄品质模拟模型，以期动态预测设施番茄收获期、产量和品质。最后提出番茄周年生产与环境调控的小气候指标体系，研究结果可望为设施番茄品质调控提供科学依据。

项目以番茄品种“金冠5号”（Solanum lycopersicum.cv. Jinguan5）为试材，设置不同日平均温度、昼夜温差人工环境控制试验，研究了叶片光合特性、番茄各器官中可溶性糖和蔗糖含量、叶片中游离氨基酸和可溶性蛋白含量、不同器管干物质分配比例、内源激素对昼夜温差的响应。研究表明12℃昼夜温差处理比0℃处理可显著增加番茄叶绿素含量。在番茄不同发育阶段，番茄叶片的Pmax、Amax、Aq及Ce均以6℃昼夜温差处理最高，0℃昼夜温差处理次之，12℃昼夜温差处理最低。番茄的最大光化学效率Fv/Fm、光化学淬灭qP、电子传递速率ETR均以6℃昼夜温差处理时最大，0℃昼夜温差时最低。根、茎和叶片中的可溶性糖含量在花期、座果期和果实膨大期均以0℃温差 (18℃/18℃)处理最高，12℃温差处理最低；叶柄和果实的可溶性糖含量以12℃温差处理最高，0℃温差处理下最低；根、叶片、叶柄、花和果实中的蔗糖含量均以12℃温差处理最高，茎中的蔗糖除在果实膨大期外，其它各生育期也以12℃最大；叶片游离氨基酸和可溶性蛋白含量以12℃处理最高，6℃温差处理次之，0℃温差处理最低；而干物质在果实中的分配比例比例以6℃温差处理下最大，12℃温差处理下最小，茎的干物质分配比例以12℃温差处理下最大，6℃温差处理下最小。研究认为在日均气温18℃条件下，昼夜温差0-12℃范围内，昼夜温差越大，利于果实中可溶性糖、蔗糖的积累，游离氨基酸和可溶性蛋白含量越高，而适当加大昼夜温差利于干物质向果实中转移，过高、过低温差不利于果实干物质积；25℃均温下，GA3、IAA和ZT含量均在6 ℃ DIF下含量最高；32℃均温下，GA3含量随温差增大而增加，ZT含量以6℃DIF最高，IAA含量则以6℃DIF最低。建立了设施番茄基于昼夜温差的生长模型。不同昼夜温差处理下，根、茎、叶的干物质分配比例均随辐热积增加呈指数递减关系，而果实的干物质分配比例、可溶性糖、蔗糖、可溶性蛋白含量随辐热积增加呈Logistic模型递增关系，提出了设施番茄生长和品质调控模型及调控气象指标。. 本项目共发表论文7篇论文，其中2篇SCI（E）收录2篇，Ei收录1篇，出版专著1部，申请专利6项，授权3项。