CO2浓度升高与大气增温对西北半干旱区马铃薯生理生态的协同影响

Climate warming is one of several challenges on agriculture in semiarid areas of the Northwest in China. The experts at home and broad made a deeply study on the influence of climate warming and CO2 doubly increased on crops such as rice, wheat, cotton and maize and made a great progress. However, China's researches are mainly focusing on the separate study of climate warming and CO2 increasing on potatoes, without in-depth exploration into the collaborative influence and mechanism on the physiological ecology of potatoes..The new open-top chamber (OTC) and infrared radiant heater experiment are employed to study the influence process and mechanism of cooperative interaction of climate warming and CO2 increasing on the growth, development, morphological structure, tuberization, water ecophysiology, carbon exchange as well as quality . (1) We analyze the influence of collaborative interaction of climate warming and CO2 increasing on the growth, development, morphological structure and tuberization, determining the relationship between climate warming & CO2 increasing and growth period and intervals of growth period; we conclude the rules and mechanism of stem height, density, fresh (dry) weight, leaf area index, tubers and tuber weight. We set up the climate model for climate & CO2 concentration as well as growth and yield formation of potatoes. (2) We analyze the influence features of collaborative interaction of climate warming and CO2 increasing on carbon exchange, determining the change rules and mechanism for photosynthetic rate, maximal light energy transformation, light compensation point, light saturation point, three fundamental points temperature, CO2 concentration compensation point and CO2 concentration saturation point; we analyze the influences on respiration action of potatoes, determining the influences and mechanism on respiratory rate, light respiration and dark respiration. We study the influence of water physiological characteristics, determining the relationship between collaborative interaction of climate warming and CO2 increasing and stomatal conductance, transpiration rate and water potential gradient, establishing the multiple linear regression model for climate warming and CO2 increasing as well as water use efficiency at leaf level and water use efficiency at yield level. (3) We study the influence of collaborative interaction of climate warming and CO2 increasing on quality on potatoes, determining the change rules and mechanism for starch content, protein content, fat content as well as coarse fiber content. .We suppose that there is a scientific significance in enriching the agricultural meteorology theory and a realistic significance in improving the ability of potatoes to respond to climate warming in semiarid areas of the Northwest in China in this project.

气候变暖对西北半干旱区农业生产带来严峻挑战，国内外学者就大气增温和CO2浓度倍增对稻、麦、棉、玉米等作物影响的研究已取得重大进展，但对我国主要作物马铃薯影响研究仅限于大气增温与CO2浓度升高分别单因素对马铃薯影响的研究，其交互协同作用对马铃薯生理生态影响及其机理等尚不够深入和系统。本项目采用新型开顶式气室（OTC）与红外辐射增温模拟试验，研究大气增温和CO2浓度升高交互协同组合情景对马铃薯生长发育、植物形态结构、块茎形成、水分生理生态、碳交换、品质的影响过程及其机制，明确马铃薯生长发育对气候变暖和CO2浓度升高的响应关系，揭示大气增温与CO2浓度升高对马铃薯生理生态的协同影响及机理，对丰富马铃薯农业气象学的基础内容有重要价值，为提高西北半干旱区马铃薯产业应对气候变暖能力，充分利用农业气候资源提供理论依据。

气候变暖对农业生产带来严峻挑战，国内外学者就大气增温和CO2浓度倍增对稻、麦、棉、玉米等作物影响的研究已取得重大进展，但对马铃薯影响研究仅限于大气增温与CO2浓度升高分别单因素影响的研究，其交互协同作用对生理生态影响及其机理等尚不够深入和系统。. 本项目2016－2018年连续3年于马铃薯生长季在西北半干旱区采用新型开顶式气室（OTC），开展了CO2 浓度升高和气候变暖对马铃薯生理生态的影响模拟试验，获得了大量试验数据，研究了大气增温和CO2浓度升高交互协同组合情景对马铃薯生长发育、植物形态结构、块茎形成、水分生理生态、碳交换、品质的影响过程及其机制。. 其重要成果一是确定了半干旱区马铃薯生育期主要气象要素的适宜性阈值。通过观测试验获得了气候变化背景下马铃薯生长发育特征，弄清了气候变化对马铃薯影响的关键因子及其关键期，确定了半干旱区马铃薯生育期主要气象要素的适宜性阈值。建立了气候变化对马铃薯产量影响的模型。二是构建了CO2浓度升高和增温下马铃薯光响应曲线模型。研究了大气增温与CO2浓度升高交互协同作用对马铃薯碳交换和水分生理生态的影响，揭示了大气增温与CO2浓度升高对光合作用和叶片水平水分利用效率的影响及机制。构建了基于大气增温和CO2浓度升高的光响应曲线模型；发现马铃薯对照试验光响应曲线模型与大气增温与CO2浓度升高交互协同作用条件下光响应曲线模型存在显著差异。三是明确了气候变暖和CO2 浓度升高交互协同作用对马铃薯主要生理、生态特性影响的关系。四是揭示了CO2 浓度升高和增温交互协同作用对马铃薯生理、生态特性影响规律、过程及其机理。. 该成果增强了气候变化对马铃薯生理生态影响机制的认识，为马铃薯产业应对气候变化提供了科学参考。成果丰富了气候变暖背景下马铃薯农业气象学科的内容，为马铃薯产业结构调整、种植制度优化、栽培方式改进提供了科学依据，对西北贫困地区精准扶贫及地方经济发展有重要意义。