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地球大气中CO_2浓度的增加已引起了人们对CO_2对植物的影响,尤其是对世界粮食供应的未来展望的兴趣。水稻是一种主要的粮食作物,人们对CO_2浓度在水稻生理生长期和整个生育期方面的影响了解相对较少,而这是一个水稻品种对一特定地区环境适应性的一个重要方面。本研究的目的是确定一个当代改良水稻品种(Oryza sativa,品种 IR-30)在两个对照的光周期下对不同CO_2浓度的响应。在整个生育期中,水稻植株生长在置于室外、采用自然光照并由计算机控制环境条件的人工气候室中。室内的CO_2浓度分别为160、250(低于环境浓度)、330(环境浓度)、500、660和900(高于环境浓度)μmol CO_2/mol 空气。在1987年,整个试验进行了两次。第一次即早稻试验在营养生长阶段内延长了光周期,而第二次即晚稻(LPR)试验只利用自然出现的光周期。在两个试验中,营养生长期的主茎叶片发育速率均比生殖生长期的主茎叶片发育速率快,同时在营养生长阶段,出叶速度随CO_2处理而加快。在晚稻试验中,与等于环境CO_2浓度和低于环境CO_2浓度的处理相比,高于环境CO_2浓度处理下的水稻幼穗分化和孕穗期出现较早,且整个生育期缩短。这种随CO_2浓度上升而产生的植物发育加速现象与CO_2引起的营养生长阶段内主茎叶片的减少有关。相对于晚稻试验,在早稻试验中水稻植株发育对CO_2的响应的减弱是由人为延长光周期迫使生殖生长发育阶段推迟引起的,在高于环境浓度处理中更是如此。鉴于全球大气中CO_2浓度的持续增大,CO_2导致的发育加速和全生育期缩短可能会成为一个参与挑选水稻品种和安排特定地区农事活动的水稻学家和育种学家感兴趣的问题。
The increase of CO 2 concentration in the Earth’s atmosphere has caused people’s interest in CO 2 on plants, especially the future of the world’s food supply. Rice is a major food crop and relatively little is known about the effects of CO 2 concentration on physiological growth and overall growth of rice, which is an important aspect of the environmental adaptability of rice varieties to a particular area. The purpose of this study was to determine the response of a contemporary improved rice variety (Oryza sativa, cultivar IR-30) to different CO 2 concentrations over two control photoperiods. Throughout the growing season, rice plants grew in artificial climatic chambers that were outdoors, naturally illuminated, and controlled by computers. Indoor CO 2 concentrations were 160,250 (below ambient), 330 (ambient), 500, 660 and 900 (above ambient) μmol CO 2 / mol of air, respectively. In 1987, the entire experiment was conducted twice. The first test, the early rice test, prolonged the photoperiod in the vegetative growth phase whereas the second test, the late rice (LPR) test, utilized only the naturally occurring photoperiod. In both experiments, the growth rate of main stems in vegetative growth period was faster than that of main stems in reproductive growth stage, and at the vegetative growth stage, the leaf emergence rate was accelerated with CO_2 treatment. In the late rice experiment, panicle differentiation and booting stage appeared earlier and the whole growth period shortened under the treatment of environmental CO 2 concentration, compared with the treatment of environmental CO 2 concentration and environmental CO 2 concentration. This accelerated plant development with the increase of CO 2 concentration is related to the reduction of main stem leaves in vegetative growth stage induced by CO 2. Compared with the late rice trial, the weakened response of rice plants to CO 2 in the early rice trial was caused by the delay of the reproductive growth stage by artificially prolonging the photoperiod, especially at higher than ambient concentrations. Given the continued increase in CO 2 concentrations in the global atmosphere, accelerated development due to CO 2 and shortened full-term growth may be of interest to riceologists and breeders involved in the selection of rice varieties and arrangements for farming activities in particular areas.