大气二氧化碳(CO_2)浓度和温度的增加是全球气候变化的两个最主要特征。目前空气中的CO_2浓度已从1800年的不到280 mumol/mol上升到391 mumol/mol,预测本世纪末最高将增至936 mumol/mol。伴随CO_2及其它温室气体增强的温室效应,相比1980-1999年,2100年之前全球地表平均气温将增高1.5-4.0℃。水稻是人类最重要的食物来源,为全球半数以上人口提供营养。在介绍CO_2浓度和温度增高试验平台的基础上,系统总结了CO_2浓度和气温这两个重要的环境因子特别是两者的交互互作对水稻影响的实验进展,内容包括光合作用、生育进程、分蘖发生、物质生产、籽粒产量、受精过程、碳氮代谢、稻米品质以及水稻/杂草竞争等方面。结果表明,作为光合作用的底物,大气CO_2浓度增高对水稻生产力的直接影响通常是有益的;相反,气温升高及其与CO_2的互作对水稻各生长过程的影响变异很大(从负到正),反映了处理因子(包括CO_2-温度处理水平和时间)、供试品种及其生长条件之间复杂的交互作用。目前这一方向有限的认识多来自于封闭或半封闭气室的研究,未来研究的重点是利用稻田T-FACE(Temperature-Free Air CO_2 Enrichment)技术结合气室试验展开更多更深入的学科交叉研究,研明CO_2浓度与温度的交互作用对水稻关键生长过程的影响,并找出这些互作效应的生物学机制,增强人们对气候假定情景下水稻响应的预测能力,进而更加有效地制订出应对气候变化的适应策略。
英文摘要:
The increases in air temperature and atmospheric carbon dioxide (CO_2) concentrations are the two most important attributes of global climate change. CO_2 concentrations have increased from 280 mumol/mol in 1800 to 396 mumol/ mol at present, and in the worst case scenario, it is estimated to reach 936 mumol/mol by the end of this century. Concomitant with the enhanced greenhouse effect caused by the increasing concentrations of CO_2 and other greenhouse gases, the projected rise in the global average surface air temperature before 2100 relative to 1980-1999 is about 1.8-4.0℃. Rice is one of the most important food crops for more than half of the world's population. In this review, we introduced the experimental platforms that have been used to study the effects of rising temperatures and CO_2 comcentrations on crops. Subsequently, the experimental progress achieved so far was summarized systematically, highlighting the effects of two important environmental factors-temperature and CO_2 concentration-on rice growth and development. The factors studied include photosynthesis, development process, tillers formation, biomass production, grain yield, process of fertilization, carbon and nitrogen metabolism, rice quality and rice/weed competition etc. As the main substrate for photosynthesis,the elevated concentrations of atmospheric CO_2 exhibited direct beneficial effects on rice productivity in most cases. In contrast, the effects of temperature rise, or its combined effect with higher CO_2 concentrations, on the rice growth process varied substantially (from negative to positive). This reflects the complex relationship between the treatment factors (including the CO_2,temperature treatment level and duration) and the varieties and growth conditions of rice. Until now, our knowledge in this field has mainly been obtained from the studies conducted in closed or semi-closed gas chambers. The focus of future research will be the use of rice T-FACE (Temperature-Free Air CO_2 Enrichment), in combination with chamber facilities, to carry out further multidisciplinary research. The ultimate goal will be to understand the effects of temperature, CO_2 interactions on the key processes of rice growth and the biological mechanisms involved in such interactions to improve our ability in predicting the variation in rice growth with changing climatic conditions and to develop more effectively the adaptation strategies to cope with climate change.