冬小麦理想根系构型及其可塑性对水氮胁迫响应机理研究

优良的根系构型是提高冬小麦耐旱、耐低氮的关键因素，根系可塑性是作物适应多元土壤环境的必要前提。目前大部分根系构型的筛选在无土栽培或单因子胁迫条件下进行，但筛选的品种在大田环境下大多没有目标根系表型，因此在土壤环境下挖掘理想根系构型及其可塑性显得越来越迫切。本项目将以前期水氮胁迫试验获得的12个耐受型与敏感型冬小麦品种为试验材料，通过改进原位根系观测技术—微根管的高通量性、精准性，进一步研究：（1）水氮胁迫下冬小麦耐受型与敏感型间根系构型差异，揭示耐受型的理想根系构型特征；（2）冬小麦理想根系构型在不同水氮胁迫水平下的可塑性，揭示根系-土壤水氮的互作以及根系-地上部响应规律；（3）构建根系活力等级的光谱模型，分析冬小麦的细根周转率、有效根系和功能性根系，阐明根系可塑性的对水氮因子的响应机理。本项目有望鉴定到冬小麦的理想根系构型及其可塑性，为干旱地区耐逆作物根系育种提供理论依据和技术支撑。

Superior root system architecture is a key factor to improve drought and low nitrogen tolerance of winter wheat, and root plasticity is a necessary precondition for crops to adapt to multiple soil environment. Current studies of screening for root system architecture are most conducted in the soilless culture or on single stress factor, while the screened cultivars often fail to have targeted root phenotype in the field conditions, thus it becomes increasingly urgent to identify root system architecture and its plasticity in the soil environment. This study will adopt twelve stress tolerant and sensitive cultivars of winter wheat from a previous water and nitrogen stress experiment, and improve the high-throughput and accuracy of the in situ root phenotyping method-minirhizotron, to further study: (1) differences of root system architecture between the tolerant and sensitive cultivars of winter wheat under water and nitrogen stress, to reveal the traits of ideal root system architecture of tolerant cultivars; (2) plasticity of the ideal root system architecture of winter wheat under different levels of water and nitrogen stress, to disclose the interactions of root-soil environment and the response regular of root-aboveground; (3) construction of a spectral model of root activity levels, to analyze the fine roots turnover, effective roots and functional roots, and to illustrate the response mechanisms of root plasticity to water and nitrogen factors. This study is potential to identify the ideal root system architecture and its plasticity of winter wheat, and provide theoretical basis and technical support for root breeding of stress tolerant crops in the arid areas.