小麦灌浆期是水分临界期，此时水分亏缺会导致灌浆不足而严重减产；而在高温多雨的小麦收获季节，小麦籽粒水分含量过高又容易造成穗发芽和霉变，籽粒脱水特性直接关系到收获期的早迟、收获效率、成本和安全储存。灌浆期水分的动态平衡对于小麦产量的形成和稳定具有重要意义。但颖果的水分迁移和调控因素仍未知，这已成为小麦高产和育种实践的瓶颈。前期课题组研究过小麦的灌浆和脱水速率，观察过小麦颖果的养分运输组织。在此基础上，本项目拟以扬麦16为试材，运用扫描电镜、透射电镜、micro-CT、同位素示踪、染色剂示踪、转录组测序等技术与方法，研究(1)小麦穗的维管束结构和走向、(2)小穗和颖果中的水分运输路径、(3)颖果中水分外排的机制。研究结果不仅可阐明小麦灌浆期颖果内水分运输机制与脱水路径，并为小麦抗旱抗湿新品种的选育和小麦高产优质栽培提供理论依据，还可为无气孔类果实中水分运转研究开辟新的思路和途径。

Grain filling stage of wheat is a key period of water dynamics, water deficit of grouting at this period can lead to serious losses in yield. The wheat harvest season always followed with high temperature and rainy, which can cause high grain moisture and result in spikes germination and mildew. Seed dehydration characteristics can directly affect harvesting time, harvesting efficiency, cost and seed storage safety. Water dynamic balance of filling stage brings great significance to the formation and stability of wheat production. However, water migration path in caryopsis is still unknown, its regulating factors also unclear. This problem become a key bottleneck of theoretical research and crop breeding. We preliminarily detected grouting and the dehydration rate of large area cultivated and high-yield wheat varieties, and we also did anatomy study of nutrient transport organization of wheat caryopsis. On this basis, we use Yangmai16 as test materials; intend to use scanning electron microscopy and transmission electron microscopy combined with micro-CT study, isotope tracer and sample dyeing tracking, transcriptome sequencing technologies to perform researches as follows: (1) Structure and arrange direction of vascular bundles in wheat caryopsis; (2) The water transport pathway in spikelets and caryopsis; (3) The mechanism of water efflux in wheat caryopsis. We intend to preliminary clarify water transport mechanism and dehydration pathway at caryopsis filling stage, to provide theory supports for breeding new varieties of drought-resistant and the high-yielding wheat. This research will also provide new ways for the studies of water dynamics in astomatous fruits.