根域限制栽培下葡萄果实品质提升与树体水分利用关系研究

Root restriction is a new technique in fruit tree cultivation, the principle of which is based on the fact that vegetative growth and reproductive growth of fruit trees could be regulated by restricting root system growth.Root restriction can reduce fruit tree water consumption and improve fruit quality significantly; this implies that the movement and distribution of water and photosynthate change under root restriction. The water uptake, movement and distribution in fruit tree are a complicated system, which also strongly influences fruit growth and quality. Former studies about root restriction focused mostly on nutrient uptake, hormone regulation，and photosynthesis, but rarely involved the relation between water movement and fruit quality.In this project, we use some advanced techniques including fluorescent dye tracing, double isotopic tracing, cell ultrastructure and three dimensional structures of vascular bundles, expression and quantitative determination of aquaporins, and other plant physiological indices analyze; the interactions between water movement in grape vine and berry quality are studied systematically, the spotlight in this project is the response of fruit quality to changes of water information in grape vine tree under root restriction. Through the studies in this project, we will understand clearly the water dynamic movement and hydraulic connections from soil to the roots, xylem, leaves and fruits under root restriction, and reveal the effects of root restriction on water-saving and fruit quality improving.These studies in this project will provide important theories for water physiology of fruit tree, and also have academic value to study fruit quality and great pratice significance to develop new cultural technique in fruit tree.

基于感知外界胁迫的根源信号理论和果树营养生长与生殖生长调控原理而提出的果树根域限制栽培技术实现了节水提质的高效生产目标，但节水提质的机理尚未阐明。欲阐明此机理须从根域限制栽培模式下果树水分迁移调控机理，以及水分迁移与果实品质互作关系研究入手。前期我们从营养吸收、激素调控、光合作用等方面系统研究了根域限制影响果树生长和干物质分配的机制。本项目是在以上研究基础上，通过同位素示踪、细胞超微结构观察、水通道蛋白表达与定量测定、水分生理和果实品质生理指标分析等研究，系统研究根域限制下葡萄树体水分迁移与水通道蛋白调控机理，以及水分迁移与果实品质互作关系，重点解析对树体水分信息流动的响应，揭示根域限制下树体水分有效性动态变化以及根系-木质部-果实之间水力联系与果实品质提升相互作用机制。该项目为研究果树水分生理代谢提供重要理论依据，对研究果实品质调控具有重要的学术意义，同时该项目对开发果树高品质栽培新技术具有重要的实践意义。

基于感知外界胁迫的根源信号理论和果树营养生长与生殖生长调控原理而提出的果树根域限制栽培技术实现了节水提质的高效生产目标，以往人们从营养吸收、激素调控、光合作用等方面系统研究了根域限制影响果树生长和干物质分配的机制。本课题创新了研究方法，通过染料与同位素示踪、细胞结构观察、水分生理和果实品质生理指标分析等研究，系统研究了根域限制下葡萄树体水分迁移规律与果实品质互作关系，揭示了根域限制下树体水分有效性动态变化。该项目为研究果树水分生理代谢提供了重要理论依据，对研究果实品质调控具有重要的学术意义，同时该项目对开发果树高品质栽培新技术具有重要的实践意义。本课题从根域限制栽培模式下果树水分迁移与果实品质互作关系研究入手，采用染料示踪和显微观察研究方法，研究了根域限制下葡萄树体水分运输动态与途径的结构变化，结果表明根域限制下新梢木质部面积减小，木质部导管粗度下降，导管水分运输效率受到根域限制胁迫抑制。采用植物组织透明与显微观察，从解剖结构角度研究了根域限制下葡萄新梢各着生器官的水分运输途径，结果表明新梢上着生的叶片、副稍、果穗、冬芽等器官在水分纵向运输途径上存在独立性，影响水分进入各个器官效率的主要因子是各器官水势大小，根域限制下新梢叶片与果实水势都低于对照，叶片气孔密度增加，气孔开张角度下降，水分蒸腾下降，当根系水分充足时，水分进入到果穗中增加，同时糖分在果实中的卸载增加。采用同位素示踪法，研究葡萄树体水分迁移规律，结果表明了根域限制下叶片水势下降。采用荧光染料示踪与超微结构观察法，研究了根域限制下葡萄果实细胞结构与细胞凋亡情况，结果表明在根域限制下果肉细胞变小，细胞壁增厚，内质网数量增加，在果实发育的第二次快速生长期，果肉细胞死亡数量低于对照，果肉细胞壁溶解数量也比对照低，这对维持果肉细胞功能，尤其是糖分积累有利。