膜下滴灌有限灌溉增产下棉花非叶器官光合特性及与群体光合功能关系的研究

Xinjiang Province has resource superiority, including sunlight and heat, in cotton production. In China, cotton production of Xinjiang plays an important role in the development of cotton industry. However, the lack of water resources is the core limiting factor of cotton production. The photosynthetic stress tolerance no-leaf organ was enhanced and its relative contribution on yield was significantly increased under water deficit. The results showed that photosynthetic stress tolerance of no-leaf organ can compensate the negative effects of leaf photosynthetic functions caused by water deficit and achieving efficient utilization of limited water supply. These results provided an important breakthrough for studying physiological mechanism and regulation approach of high yield cotton under limited irrigation. By researching photosynthetic characteristics of cotton no-leaf organ under yield-increasing of limited irrigation, the study researched difference of enduring adversity stress and regulatory mechanisms on photosynthetic characteristics of leaf and no-leaf organ under limited irrigation, discussed photosynthetic characteristics of green organs in different levels and its coupling relationship with canopy photosynthetic functions during the yield formation, enucleated physiological and ecological mechanism of increasing cotton canopy photosynthetic functions with drip irrigation. The study also explored possible ways and control measures of extending duration of high efficient canopy photosynthesis and increasing canopy photosynthetic products at late growth stages by using plasticity of photosynthetic enduring adversity stress of no-leaf organ. The research results provided the theoretical and technique foundation for formulating system of cotton super-high-yielding cultivation technology and breeding super high-yield new varieties.

新疆具有发展棉花的光热资源优势，水资源不足是限制棉花生产的核心因素。水分亏缺下棉花非叶器官光合抗逆性增强，且对产量的相对贡献率显著提高，表明非叶器官光合抗逆性可弥补水分亏缺对叶片光合功能的负面效应，实现有限水分的高效利用。这为研究有限灌溉下棉花高产的生理机制及调控途径提供了重要突破口。本项目从有限灌溉增产条件下棉花非叶器官光合性能入手，研究有限灌溉条件下棉花叶片及非叶器官光合性能耐逆差异及其调节机理，探讨产量形成过程中不同层次绿色器官光合性能与群体光合能力的耦合关系，阐明增强有限灌溉棉花群体光合功能的生理生态机制；探寻利用非叶器官光合耐逆的可塑性，延长群体高效光合持续期，增加生育后期群体光合物质生产的可能途径和调控措施。研究结果为棉花超高产栽培技术体系的制定及超高产新品种的选育提供理论依据和技术支撑。

光合作用是作物产量形成的物质基础。探寻通过改变土壤水分供应， 挖掘棉花“铃-叶系统”光合性能潜力，提高棉花在干旱下的光合抗逆性，促进光合产物优先向棉铃分配，实现棉花高产节水对作物的生长发育具有重要意义。本项目以新疆自育棉花品种为研究材料，研究不同水分亏缺对田间条件下棉花叶片PSII活性的影响，分析了非叶器官光合作用与群体光合生产能力的关系及其对产量形成的贡献，探讨了主要栽培调控措施对不同绿色器官光合结构与功能的调节效应。取得的重要结果有：（1）明确了不同水分条件下叶片的电子传递速率和CO2同化速率间无明显的线性关系。JIP-测定分析表明，水分亏缺下单位有活性的PS II反应中心数量降低、PS II功能性天线增大、PS II激发能的连通性降低，引起PS II反应中心功能的下降，是导致水分亏缺下CO2同化速率降低的主要原因。（2）探明了在开花后21天左右，主茎叶开始衰老，果枝叶和铃壳对棉铃干物质积累的相对贡献率升高。因此，棉花生育后期果枝叶和铃壳的光合作用对其产量形成具有重要的作用。亏缺滴灌可使“铃叶系统”的光合电子传递受到不同程度的抑制，且随着发育进程的推进，果枝叶光能转化效率在棉铃发育的关键时期逐渐增强，且铃壳也起到一定的补偿作用。（3）提出了有限滴灌高密度处理，在保持较高叶面积指数条件下，通过调节叶倾角，保证冠层中、下部较高的光吸收率，进而提高冠层总光吸收率，有利于提高盛铃期以后的群体光合生产能力；生殖器官生物量积累理论最大值和最大相对生长速率较大，快速生长持续时间短，有利于较高生物量的形成。这些结果回答了在有限滴灌下棉花是如何通过挖掘非叶器官光合抗逆潜力，提高群体物质生产能力，促进了较多的干物质分配到经济器官，从而实现棉花高产节水，研究结果对进一步挖掘棉花光合增产潜力提供了理论依据。项目共发表文章2篇，其中SCI刊物2篇。