Fundamental study on environment control for high quality fruit production based on dynamics of mass accumulation into fruits

番茄果实生长过程中物质通量的动态变化从果实水分平衡、韧皮部和木质部向果实内的运输等方面分析了环境条件对果实水分平衡的影响。近年来，研究开发了多种植物果实质量通量测量仪器，主要有：1。多室系统，用于在线测量六种植物完整果实和叶片的蒸腾、呼吸和光合作用; 2.果实膨胀生长和液流的在线测量系统; 3.韧皮部液流和木质部液流通过花梗的个体评价方法; 4. EDTA法测定花梗光合产物通量的相对强度; 5.追踪果实汁液回流的方法; 6.化学元素通过韧皮部和木质部累积到果实中的通量的个体评价方法。利用这些新发展的方法，定量地阐明了光照、昼夜温度、水分胁迫和盐胁迫对果实质量通量动态的影响。特别是，韧皮部运输到水果的重要性被明确提出。例如，韧皮部运输到果实中取决于果实呼吸以及叶片光合作用的白天光和温度的增加，并且发现韧皮部汁液的贡献更高（在胁迫条件下为90%，在非胁迫条件下为70%）。此外，有人建议，生产高品质的番茄果实具有更高浓度的糖，酸和化学元素，可以通过短期盐胁迫处理，从深海海水中提炼的盐。

Dynamics of mass fluxes in a growing fruit of tomato )Lycopersicon esculentum Mill.) as affected by environmental conditions were analyzed with special reference to fruit water balance and phloem and xylem transport into the fruit. Many kinds of plant instrumentations for measuring mass fluxes in the fruits were newly developed as follow : 1. Multiple chamber system for on-line measurements of transpiration, respiration and photosynthesis in intact fruits and leaves on six plants ; 2. System for online measurements of fruit expansive growth and sap flux through the pedicel ; 3. Method for individual evaluation of phloem sap and xylem sap fluxes through the pedicel ; 4. EDTA method for evaluation relative intensity of fluxes of photoassimilates through the pedicel ; 5. Method for tracing sap backflow from the fruit ; 6. Method for individual evaluation of fluxes of chemical elements accumulated into the fruits through phloem and xylem. By using these methods newly developed, effects of light, day-night temperature, water stress and salt stress on dynamics on mass fluxes into the fruits were elucidated quantitatively. In particular, the importance of phloem transport into the fruits was clearly suggested. For example, phloem transport into the fruits was enhanced by light and temperature increase in the daytime depending on fruit respiration as well as leaf photosynthesis, and higher contribution of phloem sap was found (90 % under the stress conditions and 70 % under the non-stress). Furthermore, it was suggested that the production of high quality tomato fruits with higher concentrations of sugars, acids and chemical elements can be enabled by the short-term salt stress treatment with the salt refined from deep-sea water.