基于光氮互作敏感性差异的水稻产量稳定性研究

Rice growth is　offen affected by adverse weather, such as cloudy and less sunshine in southern China, which makes the fluctuation of rice yield between annual and regional,and limites the enhencing of nitrogen efficiency.In this study,the different genetypes of rice cultivars will be used to study the sensitivity difference to the interaction stress of light intensity and nitrogen applying amount.The relationship between grain yield stability and the sensitivity to the light intensity and nitrogen applying amount will be also disscussed,and typical cultivars with high and low sensitivity to the stress will be selected.Using these materials,the physiological characteristics(include photosynthetic rate and respiration rate,amino acids, proteins, starch and soluble sugar contents，enzyme activity of carbon and nitrogen metabolism, ratio of carbon to nitrogen,protective enzymes and roots activity,and so on),yield and quality formation,and the nitrogen uptakeing　under the interaction of light intensity and nitrogen applying amount will be researched.The physiological characteristics and coordination mechanisms for the rice cultivars with high and stable yield will be revealed, the laws of yield formation and nitrogen uptakeing for different rice cultivars under the stress of less sunshine will be clarified. Which is benefit for the establishment of the proper nitrogen apply techinque ,the optimun cultivation methods, and the selections of the wide adaptability cultivars for the rice of southern China.

针对我国南方地区水稻生长期间常常遭遇阴雨、寡日照等不利天气，不仅造成水稻产量的年际间和地域性波动，而且影响水稻氮素的吸收与利用，造成氮肥利用率难以提高的问题，从不同基因型水稻品种对光氮互作的敏感性差异入手，研究其与产量稳定性的关系，探明不同光氮互作敏感型水稻品种在光氮互作条件下的生理生化特征（包括光合速率、呼吸速率、氨基酸、蛋白质、淀粉和可溶性糖含量、碳氮代谢相关酶活性、C/N、相关保护酶活性、根系活力等）、产量及品质的形成、氮素的吸收利用等方面的差异，揭示稳产高产型水稻品种的内在生理特征及协调作用机制，明确不同光氮互作敏感型水稻品种在弱光胁迫下的产量形成及氮素吸收利用规律，为南方地区高效施氮技术的建立和水稻高产、稳产、高效栽培以及广适性高产水稻品种的选育提供理论依据。

项目针对我国南方地区水稻生长期间常常遭遇阴雨、寡日照等不利天气，不仅造成水稻产量的年际间和地域性波动，而且影响水稻氮素的吸收与利用，造成氮肥利用率难以提高的问题，采用大田试验，在分别筛选出3个稳产型和不稳产型双季早晚稻典型品种的基础上，研究了不同产量稳定型双季稻品种的形态特征、生理生化特征及其与光氮互作敏感性的关系，探讨了弱光胁迫对双季稻生长影响的关键时期，分析了弱光胁迫下双季稻的氮肥调控策略。结果表明，双季稻品种产量的稳定性与其对光氮互作的敏感性关系密切，稳产型早稻品种对弱光和氮素均不敏感，而不稳产型早稻对弱光和氮素均较敏感；稳产型晚稻品种对弱光不敏感，而不稳产型晚稻品种对弱光较敏感，但对氮素敏感性存在品种间差异。稳产型双季稻品种一般表现为株高较矮、上三叶长度较短，宽度较宽，有效穗数较少，每穗粒数较多。弱光胁迫下，稳产型双季稻品种的干物质及氮素积累下降幅度小，过氧化物酶、过氧化氢酶、超氧化物歧化酶升高幅度大，丙二醛升高幅度小，硝酸还原酶和谷氨酰胺合成酶下降幅度小。不同时期弱光胁迫对双季稻产量和品质的影响表现为灌浆期>幼穗分化期>分蘖期。弱光胁迫下适当的提高施氮量，可促进水稻产量的提高并从一定程度上改善稻米品质。研究结果对于高产稳产型水稻新品种的选育以及双季稻的高产高效栽培具有重要的指导意义。通过项目实施，发表论文3篇，其中SCI论文1篇，核心期刊2篇，培养硕士研究生2名，其中1人继续在本校攻读博士学位，获得省科技进步二等奖1项，制订地方标准1项，申请专利1项。