Wheat ( Triticum aestivum L.) plants were grown under ambient and doubled_CO 2(plus 350 μL/L) concentration in cylindrical open_top chamber to examine their effects on the ultrastructure, supramolecular architect...Wheat ( Triticum aestivum L.) plants were grown under ambient and doubled_CO 2(plus 350 μL/L) concentration in cylindrical open_top chamber to examine their effects on the ultrastructure, supramolecular architecture, absorption spectrum and low temperature (77 K) fluorescence emission spectrum of the chloroplasts from wheat leaves. The results were briefly summarized as follows: (1) The wheat leaves possessed normally developed chloroplasts with intact grana and stroma thylakoid membranes; The grana intertwined with stroma thylakoid membranes and increased slightly in stacking degree and the width of granum, in spite of more accumulated starch grains within the chloroplasts than those in control; (2) The particle density in the stacked region of the endoplasmic fracture face (EFs) and protoplasmic fracture face (PFs) and in the unstacked region the endoplasmic fracture face (EFu) and the protoplasmic fracture face (PFu) was significantly higher than that of control. Furthermore, in some cases many more particles on EFs faces of thylakoid membranes appeared as a paracrystalline particle array; (3) The variations in the structure of chloroplasts were consistent with the absorption spectra and the low temperature (77 K) fluorescence emission spectra of the chloroplasts developed under the doubled_CO 2 concentration. Results indicate that the capability of light energy absorption of chloroplasts and regulative capability of excitation energy distribution between PSⅡ and PSⅠ were raised by doubled_CO 2 concentration. This is very favorable for final productivity of wheat.展开更多
An obvious warming in China induced by doubled carbon, dioxide as simulated by the climatic models have been found. It is also noticed that there might be drying or wetting in some parts of China induced by doubled CO...An obvious warming in China induced by doubled carbon, dioxide as simulated by the climatic models have been found. It is also noticed that there might be drying or wetting in some parts of China induced by doubled CO2 as simulated by the general circulation models(GCMs). Agricultural productivity mainly depends on the temperature, rainfall and soil moisture in China. The changes of agricultural productivity in the different parts of China induced by doubled CO2 have been estimated in this paper. It is shown that the greenhouse effect might cause increasing production in some parts of China and decreasing production in other parts of China.展开更多
Fractal geometry was applied and box dimension was used as an indicator to analyze the effects of doubled CO\-2 concentration on the root growth of plant seedlings. Results showed that doubled CO\-2 concentration disp...Fractal geometry was applied and box dimension was used as an indicator to analyze the effects of doubled CO\-2 concentration on the root growth of plant seedlings. Results showed that doubled CO\-2 concentration displayed different effects on root branching characteristics of C\-3 and C\-4 plants. There was an obvious increase of root branches in spring wheat while there were no significant effects on roots of sweet sorghum. In different soil layers, root branching of spring wheat was stimulated and this promotion was most significant in the second layer (10-20 cm), which denoted that elevated CO\-2 altered the root branching pattern. That means higher CO 2 concentration influences not only root growth but also its differentiation and development.展开更多
Effects of doubled CO_(2) and O3 concentration on Soybean were studied in open-top chambers(OTC).Under doubled CO_(2) concentration,grain yield and biomass increased,the SOD activity,vitamin C(Vc)and carotenoid(Car)co...Effects of doubled CO_(2) and O3 concentration on Soybean were studied in open-top chambers(OTC).Under doubled CO_(2) concentration,grain yield and biomass increased,the SOD activity,vitamin C(Vc)and carotenoid(Car)content also increased;Superoxide(O2-.)generating rate decreased,relative conductivity and malondialdehyde(MDA)content significantly declined.But under doubled O3 concentration,the SOD activity,Vc and Car contents declined,resulting in imbalance of activated-oxygen production,enhanced O2-.generating rate and accelerated process of lipid peroxidation and increase in MDA content and ion leakage of leaves.The final result was decreased grain yield and plant biomass.Interactive effects of doubled CO_(2) and O3 concentrations on soybean were mostly counteractive.However,the beneficial effects of concentration-doubled CO_(2) are more than compensate the negative effects imposed by doubled O3,and the latter in its turn partly counteracted the positive effects of the former.展开更多
文摘Wheat ( Triticum aestivum L.) plants were grown under ambient and doubled_CO 2(plus 350 μL/L) concentration in cylindrical open_top chamber to examine their effects on the ultrastructure, supramolecular architecture, absorption spectrum and low temperature (77 K) fluorescence emission spectrum of the chloroplasts from wheat leaves. The results were briefly summarized as follows: (1) The wheat leaves possessed normally developed chloroplasts with intact grana and stroma thylakoid membranes; The grana intertwined with stroma thylakoid membranes and increased slightly in stacking degree and the width of granum, in spite of more accumulated starch grains within the chloroplasts than those in control; (2) The particle density in the stacked region of the endoplasmic fracture face (EFs) and protoplasmic fracture face (PFs) and in the unstacked region the endoplasmic fracture face (EFu) and the protoplasmic fracture face (PFu) was significantly higher than that of control. Furthermore, in some cases many more particles on EFs faces of thylakoid membranes appeared as a paracrystalline particle array; (3) The variations in the structure of chloroplasts were consistent with the absorption spectra and the low temperature (77 K) fluorescence emission spectra of the chloroplasts developed under the doubled_CO 2 concentration. Results indicate that the capability of light energy absorption of chloroplasts and regulative capability of excitation energy distribution between PSⅡ and PSⅠ were raised by doubled_CO 2 concentration. This is very favorable for final productivity of wheat.
文摘An obvious warming in China induced by doubled carbon, dioxide as simulated by the climatic models have been found. It is also noticed that there might be drying or wetting in some parts of China induced by doubled CO2 as simulated by the general circulation models(GCMs). Agricultural productivity mainly depends on the temperature, rainfall and soil moisture in China. The changes of agricultural productivity in the different parts of China induced by doubled CO2 have been estimated in this paper. It is shown that the greenhouse effect might cause increasing production in some parts of China and decreasing production in other parts of China.
文摘Fractal geometry was applied and box dimension was used as an indicator to analyze the effects of doubled CO\-2 concentration on the root growth of plant seedlings. Results showed that doubled CO\-2 concentration displayed different effects on root branching characteristics of C\-3 and C\-4 plants. There was an obvious increase of root branches in spring wheat while there were no significant effects on roots of sweet sorghum. In different soil layers, root branching of spring wheat was stimulated and this promotion was most significant in the second layer (10-20 cm), which denoted that elevated CO\-2 altered the root branching pattern. That means higher CO 2 concentration influences not only root growth but also its differentiation and development.
基金the National Natural Science Foundation of China(Grant No.40271111)the Knowledge Innovation Major Orientation Program(KZCX2-408,SCXMS0302).
文摘Effects of doubled CO_(2) and O3 concentration on Soybean were studied in open-top chambers(OTC).Under doubled CO_(2) concentration,grain yield and biomass increased,the SOD activity,vitamin C(Vc)and carotenoid(Car)content also increased;Superoxide(O2-.)generating rate decreased,relative conductivity and malondialdehyde(MDA)content significantly declined.But under doubled O3 concentration,the SOD activity,Vc and Car contents declined,resulting in imbalance of activated-oxygen production,enhanced O2-.generating rate and accelerated process of lipid peroxidation and increase in MDA content and ion leakage of leaves.The final result was decreased grain yield and plant biomass.Interactive effects of doubled CO_(2) and O3 concentrations on soybean were mostly counteractive.However,the beneficial effects of concentration-doubled CO_(2) are more than compensate the negative effects imposed by doubled O3,and the latter in its turn partly counteracted the positive effects of the former.
