秸秆地膜带状覆盖延缓间作小麦玉米根冠衰老的光合生理及分子机制

耕作与覆盖方式是改善土壤生态环境而延缓单作作物根冠衰老的高效措施，但在间作模式中尚不清晰。近年来，申报人将不同耕作与覆盖措施应用于间作模式，通过调控带间水分竞争互补及热量传输机制而进一步提高间作优势，但对其根冠衰老的光合生理及分子机制研究不足，生产中缺乏耕作覆盖措施延缓衰老而增强间作生产力的理论基础。项目以小麦间作玉米为研究对象，在不同秸秆与地膜覆盖方式组合下：(1)检测作物根冠衰老、光合生理、荧光动力等指标，明确小麦玉米根冠衰老响应秸秆地膜覆盖的生理机制；(2)测定光合关键蛋白、酶活性及基因表达量，揭示小麦玉米根冠衰老对秸秆地膜覆盖的分子响应机制；(3)分带分层测定群体光照强度、冠层温度与土壤温度、水分及养分含量，明确引起根冠衰老的主要因子；4)运用隶属函数法综合评价各衰老指标，阐明秸秆地膜覆盖延缓间作小麦玉米根冠衰老的调控途径。项目实施将为深入挖掘间作优势而建立可持续间作模式提供依据。

Tillage and mulching patterns are the effective measures to improve the soil ecological environment and delay root-canopy senescence of sole crops, but it is not clear in intercropping system. In recent years, different tillage and mulching practices were applied to intercropping system to further improve the intercropping advantage via regulating the mechanism on the soil water competition and complementary and soil heat transfer between intercropped strips by applicant of this project. However, the research on the photosynthetic physiology and molecular mechanism of root-canopy senescence was insufficient, and there is lack of theoretical basis for tillage and mulch measures to delay senescence and enhance intercropping productivity. Therefore, the typical wheat-maize intercropping system are employed in this project under different combinations of straw retention and plastic film mulching patterns. The objectives of this research are to: (1) determine the dynamic of various indicators, such as, root-canopy senescence, photosynthetic source, photosynthetic physiology, chlorophyll fluorescence kinetics of intercropping wheat and maize, and clarify the physiological mechanism of intercropping wheat and maize in response to strip mulching with straw and plastic film; (2) determine the key photosynthetic proteins, the activities of key photosynthetic enzymes, and the expression levels of key photosynthetic genes by using molecular biological methods were used to in order to reveal the molecular mechanism of the root-canopy senescence for intercropping wheat and maize in response to strip mulching with straw and plastic film; (3) detect the spatio-temporal dynamics of light intensity, canopy temperature in aboveground, and soil temperature, soil moisture and nutrient contents in belowground of each intercrop strip, and clear the main factors causing root-canopy senescence for intercropping wheat and maize; (4) comprehensively evaluate the senescence indexes by using the subordination function method, and elucidate the cof strip mulching with straw and plastic film to delay root-canopy senescence of intercropping wheat and maize. This project will definitely contribute to provide vital theoretical basis for enhancing the yield effect of intercropping and establishing the sustainable intercropping system.