节水灌溉下小麦水分来源转换和水分利用效率的稳定性同位素研究及其地下生物学机制

Water resource shortage has become the urgent problem limiting wheat (Triticum aestivum L.) production in China. A crucial target of wheat production is to develop water-saving agriculture to reduce irrigation water and increase the water use efficiency (WUE). Under different moisture conditions, water sources of wheat shift among irrigation water, soil water, precipitation and groundwater. This is one of the significant theoretical bases of water-saving and high-yield wheat production. However, the biological mechanism of water sources shift in wheat is still not clear. Root is the most important organs for water utilizing in wheat, its distribution in soil profile and functional traits has a significant influence on water resource shift and water use efficiency. However, there remains controversy about recent researches on relation between root and water utility patterns. Stable isotope technology has been proved to be a effective way to study the water resources and water use efficiency in wheat, with security, accuracy and non-interference. Based on plant – water sources relationship, using stable hydrogen, oxygen and carbon isotope technology to analysis linking among water sources shift, water use efficiency and root characteristics in wheat, the research aimed to reveal the adaptive mechanism of wheat in high-yield production with limited irrigation.

水资源短缺是我国小麦(Triticum aestivum L.)生产的重要限制因素。降低灌水量，提高水分利用效率是小麦节水栽培的有效途径。不同供水条件下，小麦对不同来源水分（灌溉水、土壤贮水、降水、地下水等）的利用存在差异，这是小麦节水高产栽培的重要理论基础之一，但其生物学机制尚不明确。根系是小麦吸收利用水分的最主要器官，其在土壤剖面的分布和功能性状对小麦水分来源转换和水分利用效率具有重要影响，但目前关于根系与水分利用格局关系的研究尚存争议。稳定性同位素技术以其安全、准确、无干扰等优越性，为研究小麦的水分来源和长期水分利用效率提供了有效的方法。本项目以植物-水分关系为切入点，利用稳定性氢、氧和碳同位素技术研究不同灌水条件下小麦的水分来源转换、水分利用效率与根系性状的关系，为揭示高产小麦在节水灌溉条件下的适应机制提供理论依据。