渍水胁迫下直播水稻萌发出苗对种子引发处理的响应机制研究

水稻直播是一项减轻劳动强度，提高劳动效率，便于机械化的新型水稻种植模式。然而，水稻直播对整田要求高，田面不平整或者播种后遭遇连续强降雨，容易导致淤种和烂芽，使出苗率降低，全苗难。已有研究表明种子引发处理可以显著提高逆境条件下水稻的出苗速度、出苗率和整齐度。而关于种子引发处理对直播水稻渍水胁迫下萌发出苗的影响以及调控机理的相关研究还鲜有报道。本项目拟采取盆栽和大田试验相结合的方法，研究引发处理对直播水稻渍水胁迫下萌发出苗的影响及其机理。旨在探索在渍水胁迫条件下促进直播水稻种子萌发出苗的种子引发处理，探明不同渍水深度、不同渍水持续时间下直播水稻萌发出苗对种子引发处理的响应机制，揭示引发处理诱导的种子萌芽期耐渍的生理生化机制，明确不同类型水稻品种对不同种子引发处理反应的差异及其机理。为促进渍水胁迫下直播水稻“早生快发”引发处理技术的研发提供理论依据。

Direct-seeded rice system has the potential to decrease the work intensity, increase the work efficiency, and be liable to mechanization. However, direct-seeded rice usually suffers with low germination rate and poor crop establishment due to waterlogging stress, which is caused by uneven soil surface or continuous heavy rainfall after sowing. Previous studies have shown that seed priming treatment significantly improved the crop establishment under stress conditions. Nevertheless, little research was focused on the effects of seed priming on germination of direct-seeded rice under waterlogging stress and the regulation mechanisms. In this project, the effects of seed priming treatment on germination of direct-seeded rice and its mechanism under waterlogging stress will be examined in pot and field experiments. The aims of this proposed project are (1) to explore the propriate seed priming treatments for improving the crop establishment of direct-seeded rice under waterlogging stress; (2) to identify the response mechanisms of crop establishment of direct-seeded rice to seed priming treatment under different waterlogging depths and durations; (3) the key regulatory pathways and metabolic processes related with the germination of direct-seeded rice induced by seed treatments; (3) to underpin the physiological and biochemical mechanisms of waterlogging tolerance during seed germination induced by priming treatment; (4) to examine the genotypic variations in response to seed treatments among different rice varieties and to unravel the mechanisms. The output of the proposed project will provide a scientific basis for research and development of seed treatments ensuring good crop establishment for direct-seeded rice under waterlogging stress.