控温条件下C3、C4草本植物碳同位素组成对温度的响应  

Responses of carbon isotopic composition of C3 and C4 herbaceous plants to temperature under controlled temperature conditions

作　　者：刘贤赵[1,2,3] 宿庆[3] 李嘉竹[1] 全斌[3] 李朝奎[3] 张勇[3] 王志强[3] 王国安[4] 

机构地区：[1]鲁东大学地理与规划学院,烟台264025 [2]黄土高原土壤侵蚀与旱地农业国家重点实验室,杨陵712100 [3]湖南科技大学建筑与城乡规划学院,湘潭411201 [4]中国农业大学资源与环境学院,北京100193

出　　处：《生态学报》2015年第10期3278-3287,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目(41171158);山东省自然科学基金项目(ZR2011DM007);国家重点实验室基金项目(10501-1202)

摘　　要：采取人工控制实验,探讨了6种C3、C4草本植物在昼/夜温度指标为20/12℃!36/28℃的范围内植物碳同位素组成(δ13C)及其对温度变化的响应,并结合植物比叶面积(SLA)、胞间CO2浓度(ci)与环境CO2浓度(ca)的比值、碳同化率(净光合速率Pn/胞间CO2浓度ci)等光合生长指标对植物δ13C的影响进行了分析。结果表明:所有C3、C4植物样品的δ13C值分别变化在-28.3‰!-32.1‰和-14.4‰!-17.6‰之间;在C3植物中,油菜δ13C值分布范围最集中,位于-31.1‰!-32.1‰之间;C4植物中,谷子δ13C值分布范围最窄。在控制的温度范围内,3种C3植物的平均δ13C值随温度升高而显著变低,而C4植物δ13C平均值与温度呈先增大后减小的抛物型关系,但线性回归结果未达到显著水平(P>0.05)。单个植物种的δ13C值对温度的响应不同,茄子、高粱的δ13C值与温度呈线性负相关,其它4种植物与温度均呈二次抛物线关系,这可能与不同植物种具有不同的光合最适温度以及植物δ13C分馏对温度变化的敏感程度不同有关。The stable carbon isotope ratios （δ13C） of the six herbaceous plants （including 3 C3 species and 3 C4 species） and their responses to temperature change were explored in artificial controlled environments at day/night temperatures ranging from 20/12 to 36/28℃. The correlations between plants δ13C values and the growth and photosynthetic indexes, such as specific leaf area （SLA）, the ratio of intercellular CO2 concentration （ci） to environmental CO2 concentration （ca）, and carbon assimilation rate （net photosynthetic rate Pn/ci） were also analyzed in order to investigate the temperature effects on carbon-isotope ratio of C3 and C4 herbs. The results showed that, the δ13C values of C3 and C4 plants ranged between -28.3 ‰ to -32.1 ‰, and between -14.4 ‰ to -17.6 ‰, respectively. In the three C3 species, rape （Brassica campestris） had the most concentrated distribution of δ13C values, with an range of -31.1 ‰ to -32.1 ‰; and the δ13C value distribution for millet （Setaria italica） was the narrowest in the three C4 plants. In the experimental temperature range, the mean δ13C values of three C3 plants significantly decreased with increasing temperature, while a parabolic relationship showing an increase first and then decrease existed between the average δ13C values of three C4 plants and temperature, however, the linear regression result was not significant （P 〉0.05）. The δ13C values of individual species responded differently to temperature. The δ13C values in eggplant （Solanum melongena） and sorghum （Sorghum bicolor） negatively correlated with temperature, and the δ13C values of other four species all showed a quadratic parabola relationship with temperature, which may be associated with different plant species that have different optimum photosynthesis temperature and carbon isotope fractionation capacities to temperature.

关 键 词：草本植物 碳同位素 温度 控制实验 

分 类 号：Q945[生物学—植物学]