氧-氮互作对超级稻生育后期根系生理响应机理的研究

Super rice has mass tillering, big panicle, multi spikelet and large storage capacity, but because of its root senescence, caused low seed setting rate and unstable, therefore, root senescence is an important factor restricting its yield and quality. This project aims to use synergistic effect of oxygen and nitrogen to solve root senescence. Synergy effect of root growth by different applying nitrogen and different adding oxygen will be Researched, and the best way to apply oxygen and nitrogen will be determined through pot experiment and field plot experiments. And provide root function security to increase seed setting rate and grouting rate, in order to realize high production and efficiency by regulating of rhizosphere oxygen and nitrogen to promote root growth, and maintain root activity and physiological function in late growth stage. Physiological response mechanism of super rice's root by synergistic effect of Oxygen and nitrogen in late growth period will be revealed by correlation analysis, regression analysis and modeling analysis of root metabolism index, anti-oxidation index, key enzymes of nitrogen metabolism index and yield quality indexes. The model of "synergistic effect by Oxygen and nitrogen, promoting root and keeping leaf function" will be established, which will provide the scientific basis on formulating high yield and efficiency oxygation system of super rice. The expected results will provide theoretical basis and technical support to high-yield and high-efficient cultivation of super rice, and is great significant of the sustainable development of agriculture and the safeguard food security.

超级稻分蘖多、穗型大，颖花多、库容大，但普遍存在根系早衰问题，导致结实率低且不稳定，影响其产量与品质的进一步提高。本项目拟采用氧-氮互作技术来解决超级稻根系早衰问题。项目拟通过盆栽试验和田间小区试验相结合，研究不同施氮和不同增氧对超级稻生育后期根系生长的协同影响规律，确定氧-氮互作的最佳增氧方式和施氮方式；通过调控根际氧和氮，促进根系生长，维持生育后期根系活力和生理功能，为提高结实率与灌浆率，实现高产高效提供根系功能保障。项目拟通过对根系代谢指标、抗氧化指标、氮素代谢关键酶活性等指标与产量品质等指标的相关性分析、回归分析和建模分析，揭示氧-氮互作对超级稻生育后期根系的生理响应机理。拟建立“氧-氮互作，促根保叶”的灌溉模式，为制定超级稻高产高效的增氧灌溉制度提供科学依据。预期成果将为超级稻的高产高效栽培提供理论依据及技术支持, 对农业的可持续发展和保障粮食安全具有重要意义。

粮食是关系国家经济安全的重要战略物资，我国作为粮食的生产和消费大国，虽然粮食的总产量在不断的增长，但总体仍是供不应求，供需的缺口正不断扩大，我国粮食安全形势严峻。超级稻分蘖多、穗型大，颖花多、库容大，但普遍存在根系早衰问题，导致结实率低且不稳定，影响其产量与品质的进一步提高。本项目开展试验研究，通过调控根际氧和氮两个因子，研究不同施氮和不同增氧对超级稻生育后期根系生长的协同影响规律，确定氧-氮互作的最佳增氧方式和施氮方式；通过对根系代谢指标、抗氧化指标、氮素代谢关键酶活性等指标与产量品质等指标的研究与分析，揭示氧-氮互作对超级稻生育后期根系的生理响应机理。受本项目资助，在《Irrigation and Drainage》、《农业环境科学学报》、《湖南农业大学学报：自然科学版》等期刊共发表学术论文6篇（SCI论文2篇）；授权实用新型专利1项，计算机软件著作权1项，申请发明专利1项。联合湖南省水利科学研究院，本项目的相关研究成果在望城区、湘潭县、澧县和桃江县进行了示范区推广，并一起申报了2020-2021年度农业节水科技奖获奖，《水稻增氧灌溉与节水减排研究及应用》获得第八届“大禹杯”农业节水科技奖科技成果奖二等奖（项目负责人排名第2），在“中国农业工程学会农业水土工程专业委员会学术研讨会” 做会议报告1次。.氧-氮互作促进作物根系深扎，增加根系活力，促进根系生长，提高土壤氧化还原电位，有效提高作物根系从土壤中吸收水分与营养元素，延缓根系早衰，保障了根系花后吸肥能力，减缓茎叶结构蛋白质的降解，延长绿叶寿命，有利于在较长时间内维持一定的高光效绿叶面积，从而提高花后物质的积累和转运，能较好地解决后期因根系早衰而造成的后劲不足，成穗不足和结实不足等问题，从而达到进一步挖掘超级稻增产潜能的目的，为超级稻的高产高效栽培提供理论参考及技术支持,对农业的可持续发展和保障粮食安全具有重要意义。