盐渍农田玉米细根形态可塑性对其吸水能力的影响机制与模拟研究

精准量化作物的根系吸水过程，对于制定科学高效的节水灌溉制度尤为关键，同时也是准确模拟农田土壤水分运动的前提条件。盐渍农田复杂多变的水盐胁迫环境会改变作物细根的功能和形态，造成相同长度根系吸水能力的差异并对吸水量空间分配产生影响，从而降低目前普遍使用的蒸腾权重因子类根系吸水模型的模拟精度。鉴于此，本课题以玉米为研究对象，通过根盒栽培和微区种植试验，在不同水盐胁迫条件下（胁迫水平、作用阶段、分布状况）系统监测玉米细根的生长分布动态及水分吸收过程，探索基于形态性状指标（根序、根长、直径和根龄）识别吸水细根的方法，揭示细根形态的可塑性响应机制及其空间分布状态的适应性变化规律，量化并模拟根系整体空间构型（形状特征、拓扑结构）的形成过程，由此建立考虑细根吸水能力变化的蒸腾权重因子，并将其运用在土壤水分运动模型中，为提升盐渍农田土壤水盐运移模拟精度、预测水分管理措施节水效果提供理论支撑和实用工具。

Accurately quantifying the process of crop root water uptake is critical for the development of scientific and efficient water-saving irrigation regimes, and it is also a prerequisite for accurately simulating soil water movement in fields. The complex water and salt status in saline fields will change the function and morphology of crop fine roots, cause the difference in water uptake capacity between the roots with the same length, and affect the spatial allocation of water absorption, thus reducing the simulation accuracy of the commonly used root water uptake model which allocates the transpiration by weight factors. In view of this, this project takes maize as the research object, carries out Rhizobox and micro-plot experiments, under different water and saline conditions (stress level, suffering stage, distribution status), systematically monitors the dynamics and distribution of maize fine roots, and measures its water uptake process. This project will explore the method of identifying water uptaking fine roots based on their morphological traits (root order, root length, diameter and root age), reveal the responding mechanism of fine root plasticity and the adaptive change law of fine root distribution. Moreover, this project will also simulate the formation process of root system architecture (shape characteristics, topological structure) and propose a new weight factor for transpiration allocation which can consider its varying water uptake capacity. The expected achievements of this project will improve the simulation accuracy of soil water and salt movement and provide a practical tool for evaluating the water-saving effect of water managements in saline fields.