夜间增温对玉米的产量效应及其碳氮代谢生理响应机制

Global warming is more pronounced at night than during the day, resulting in a narrowing of the diurnal temperature range. Crop production is experiencing both increases in the frequency and intensity of nocturnal warming (NW). The NW threatens the sustainability of crop production both currently and in the future. Many studies have indicated decreased crop yields as a result of NW. Therefore, it becomes more important to assess the effects of NW on crop yield. In general, the reason of decrease crop yield resulting by NW in the final analysis is altering the source-sink ratio directly or indirectly. At present, it is not well-known that whether sink or source limitation predominates in the decrease of maize yield resulting by NW. In this study, we examine the effect of NW in different corn growth stage on carbon assimilation, nitrogen absorption and allocation within plants and study corn yield response to NW after silking stage under altering carbohydrate source level by sucrose injecting in stem as well as nitrogen supply. The specific objectives for this study is to explore corn yield response to nocturnal warming and its physiological mechanism on carbon and nitrogen metabolism as well as the interaction between nitrogen application and NW on corn production. We expect to provide the theoretical basis for establish measures in corn production to acclimation to climate change in the future for sustainable development in agriculture and food security in China.

全球气候变暖主要表现为夜间气温升高，日较差呈减小趋势。作物生产正在遭受更频繁更严重的夜间升温影响，已经威胁到目前和将来农业的可持续发展。大量的研究结果表明夜间升温造成多种作物产量下降，因此研究夜间升温对作物产量的影响越来越重要。总的来说夜间升温造成作物产量下降的原因归根结底就是直接或间接的造成了作物源库比例的改变从而造成作物减产。夜间升温造成玉米产量下降是库的原因还是源的原因目前还不清楚。本申请研究不同生育时期夜间增温对玉米碳的同化和氮素吸收及其在玉米体内分配的影响，分析夜间增温对玉米的产量效应及其成因；通过茎注射蔗糖以及施用氮肥来改变源库关系，研究玉米吐丝后夜间增温对玉米产量的影响及其碳氮代谢的响应，揭示夜间升温对玉米产量效应的生理生态机制以及氮肥施用和夜间升温的互作机制，旨在为制定农业应对未来气候变化措施提供理论依据。