陕北不同年代谷子品种根系吸水能力的变化及其调控机制

谷子作为我国干旱半干旱地区重要的功能性粮食作物，是种植业结构调整的优势后备物种之一。水分不足是限制陕北地区谷子产量的主要因素，而根系作为水分吸收器官对产量形成起决定性作用。长期的育种实践在谷子产量提高方面起到了重要作用，但在谷子品种更替过程中根系吸水能力的变化缺乏研究。拟在前期研究发现谷子产量随品种更替呈现递增趋势的基础上，以近七十年来陕北地区广泛种植的典型谷子品种为材料，利用压力室、压力探针技术结合现代分子生物学手段研究不同水分条件下根系构型及根系水力学导度的差异，阐明谷子适应干旱过程中根形态结构对根系吸水能力的影响；研究根解剖学构造对水分变化的响应，揭示谷子根系解剖结构对单根吸水的调控机理；研究渗透胁迫下水通道蛋白与根细胞水力学导度的作用关系，阐明水通道蛋白功能活性随品种更替的演化趋势及对根细胞吸水的影响。结果为加快旱区优质高抗谷子新品种选育效率和实现区域水资源高效利用提供依据。

As an important functional food crop in arid and semi-arid regions of China, foxtail millet (Setaria italica) is one of advantageous reserve species for planting structure adjustment, and water shortage is the main factor limiting the millet grain yield in northern Shaanxi. Root, as the main water-absorbing organ, plays a decisive role in the yield formation. Long-term breeding practice has improved the millet yield, but the change of root water absorbing capacity in the replacement of millet varieties is still unknown, and the mechanism involved in the response of root water-uptake, which plays a crucial role in maintaining grain yield of foxtail millet, to drought stress reminded unclear. On the basis of previous study that the grain yield presents increasing trend with foxtail millet varieties replacement, with the method of pressure chamber, pressure probe and molecular biology, seven foxtail millet cultivars cultivated from the 1950s to the 2010s are selected to detect the relationship between root morphology and foxtail millet drought resistance and the co-evolutionary mechanism of the root morphology and drought resistance with the cultivars replacement. The response characteristics of root anatomy to water stress and the regulation mechanism of root anatomy to root water uptake under drought condition would be detected. The relationship of aquaporin and root cell hydraulic conductance are concerned to illuminate the evolution trend of aquaporin functional activity with the cultivars replacement and the influence of PIP on root cell hydraulic conductance. The results will provide fundamental date for elucidating the response mechanism of root water uptake to drought stress and breeding new cultivars with high-multi resistance and high yield and quality in foxtail millet.