Abstract:

Four rice (Oryza sativa L.) cultivars “IR72”, “Tesanai 2”, “Guichao 2” and “IIyou 4480” were grown in two plastic house (15 m×3 m) with 35 μmol/mol and 60 μmol/mol CO2 concentration which was controlled by computer. As compared with rice at ambient 35 μmol/mol CO2, the changes in photosynthetic rate at elevated CO2 showed up-regulation (“IR72” and “Tesanai 2”), stable (unchanged) in “Guichao 2” and down-regulation type (“IIyou 4480”). Growth rate, panicle weight, integrated water use efficiency (WUE) calculated from Δ13C and the capacity of scavenging DPPH· (1,1-diphenyl-2-picrylhydrazyl) free radical were increased at elevated CO2. An increment in total biomass was observed in three cultivars by elevated CO2, with the exception of “IIyou 4480”. Ratios of panicle weight/total biomass were altered to different extents in tested cultivars by elevated CO2. When leaf segments were subjected to PEG osmotic stress, the electrolyte leakage rate from leaves grown at elevated CO2 was less than that at 35 μmol/mol CO2. Those intraspecific variations of rice imply a possibility for selecting cultivars with maximal productivity and high tolerance to stresses adapted to elevated CO2 in the future.

水稻的光合作用、生长、碳同位素分辨作用及抗渗透胁迫性对CO₂浓度增高的响应

彭长连 段俊 林桂珠 陈贻竹 彭少麟

(中国科学院华南植物研究所, 广州 510650)

摘要：四个水稻(Oryza sativa L.)品种"IR72"、"特三矮2号"、"桂朝2号"和"Ⅱ优4480"在田间栽于含35 μmol/mol 和60 μmol/mol CO2的塑料大棚中,自然光照.高浓度CO2下供试水稻品种的光合速率变化表现为提高型("IR72"、"特三矮2号")、稳定型("桂朝2号"的Pn几无变化)和下调型("Ⅱ优4480").生长速率、穗重、由Δ13C计算而得的长期水分利用效率和清除DPPH˙自由基的能力皆增加.除"Ⅱ优4480"外,其他3个品种明显增高总生物量.供试品种的穗重/总生物量比不同程度地受到高浓度CO2的改变.叶片段经PEG渗透胁迫后,不同的生长于高浓度CO2者的电解质渗漏率较小.结果表明高浓度CO2可改变水稻的光合作用和水分关系特性, 品种间不同的响应显示了选育适于未来高浓度CO2下具有高产和抗逆性品种的可能性.

关键词：水稻   高浓度CO2   光合作用   水分利用效率   13C分辨作用   渗透胁迫

Key words: rice cultivars, elevated CO2, photosynthesis, water use efficiency, 13C discrimination, osmotic tolerance