Changes in the phenology of flowering in soybeans caused by long-term growth at elevated CO<sub>2</sub> may be important to the responses of seed yield to elevated CO<sub>2</sub>. Here we utili...Changes in the phenology of flowering in soybeans caused by long-term growth at elevated CO<sub>2</sub> may be important to the responses of seed yield to elevated CO<sub>2</sub>. Here we utilized near-isogenic lines of soybeans differing in three genes influencing photoperiod sensitivity to determine whether these genes affected the response of flowering time to elevated CO<sub>2</sub>. Six isolines of Harosoy 63 were grown at ambient (380 μmol?mol<sup>-1</sup>) and elevated (560 μmol?mol<sup>-1</sup>) CO<sub>2</sub> concentrations in the field using free-air CO<sub>2</sub> enrichment systems, in air-conditioned glasshouses with natural summer photoperiods, and in indoor chambers with day lengths of 11, 13, 15, and 17 hours. The effect of CO<sub>2</sub> concentration on flowering time varied with genotype, and there was also an interaction between CO<sub>2</sub> and photoperiod in all genotypes, as indicated by ANOVA. Elevated CO<sub>2</sub> accelerated flowering in some cases, and delayed it in other cases. For all three of the isolines with single dominant genes, elevated CO<sub>2</sub> decreased the days to first open flower at the longest photoperiod. At the shortest photoperiod, elevated CO<sub>2</sub> delayed flowering in all but one isoline. The all-recessive isoline had slower flowering at elevated CO<sub>2</sub> at both the shortest and the longest photoperiods, and also in the field and in the glasshouse. Delayed flowering at elevated CO<sub>2</sub> in the field and glasshouse was associated with an increased final number of main stem nodes. It is concluded that the E1, E3, and E4 genes each influenced how the time to first flowering was affected by CO<sub>2</sub> concentration at long photoperiods.展开更多
The potential CO2-induced impacts on the geographical shifts of wheat growth zones in China were studied from seven GCMs outputs. The wheat growth regions may move northward and westward under the condition of a doubl...The potential CO2-induced impacts on the geographical shifts of wheat growth zones in China were studied from seven GCMs outputs. The wheat growth regions may move northward and westward under the condition of a doubling CO2 climate. The wheat cultivation features and variety types may also assume significant changes. Climatic warming would have a positive influence in Northeast China, but high temperature stress may be produced in some regions of central and southern China. Higher mean air temperatures during wheat growth, particularly during the reproductive stages, may increase the need for earlier-maturing and more heat-tolerant cultivars.展开更多
The trends and features of China's climatic change in the past and future are analysed by applying station observations and GCM simulation results. Nationally, the country has warmed by 0.3℃ in annual mean air te...The trends and features of China's climatic change in the past and future are analysed by applying station observations and GCM simulation results. Nationally, the country has warmed by 0.3℃ in annual mean air temperatureand decreased by 5% in annual precipitation over 1951-1990. Regionally, temperature change has varied from acooling of 0.3℃ in Southwest China to a'warming of 1 .0℃ in Northeast China. With the exception of South China,all regions of China have shown a declination in precipitation. Climatic change has the features of increasing remarkably in winter temperature and decreasing obviously in summer precipitation. Under doubled CO2 concentration,climatic change in China will tend to be warmer and moister, with increases of 4.5℃ in annual mean air temperatureand 11% in annual precipitation on the national scale. Future climatic change will reduce the temporal and spatialdifferences of climatic factors.展开更多
文摘Changes in the phenology of flowering in soybeans caused by long-term growth at elevated CO<sub>2</sub> may be important to the responses of seed yield to elevated CO<sub>2</sub>. Here we utilized near-isogenic lines of soybeans differing in three genes influencing photoperiod sensitivity to determine whether these genes affected the response of flowering time to elevated CO<sub>2</sub>. Six isolines of Harosoy 63 were grown at ambient (380 μmol?mol<sup>-1</sup>) and elevated (560 μmol?mol<sup>-1</sup>) CO<sub>2</sub> concentrations in the field using free-air CO<sub>2</sub> enrichment systems, in air-conditioned glasshouses with natural summer photoperiods, and in indoor chambers with day lengths of 11, 13, 15, and 17 hours. The effect of CO<sub>2</sub> concentration on flowering time varied with genotype, and there was also an interaction between CO<sub>2</sub> and photoperiod in all genotypes, as indicated by ANOVA. Elevated CO<sub>2</sub> accelerated flowering in some cases, and delayed it in other cases. For all three of the isolines with single dominant genes, elevated CO<sub>2</sub> decreased the days to first open flower at the longest photoperiod. At the shortest photoperiod, elevated CO<sub>2</sub> delayed flowering in all but one isoline. The all-recessive isoline had slower flowering at elevated CO<sub>2</sub> at both the shortest and the longest photoperiods, and also in the field and in the glasshouse. Delayed flowering at elevated CO<sub>2</sub> in the field and glasshouse was associated with an increased final number of main stem nodes. It is concluded that the E1, E3, and E4 genes each influenced how the time to first flowering was affected by CO<sub>2</sub> concentration at long photoperiods.
文摘The potential CO2-induced impacts on the geographical shifts of wheat growth zones in China were studied from seven GCMs outputs. The wheat growth regions may move northward and westward under the condition of a doubling CO2 climate. The wheat cultivation features and variety types may also assume significant changes. Climatic warming would have a positive influence in Northeast China, but high temperature stress may be produced in some regions of central and southern China. Higher mean air temperatures during wheat growth, particularly during the reproductive stages, may increase the need for earlier-maturing and more heat-tolerant cultivars.
文摘The trends and features of China's climatic change in the past and future are analysed by applying station observations and GCM simulation results. Nationally, the country has warmed by 0.3℃ in annual mean air temperatureand decreased by 5% in annual precipitation over 1951-1990. Regionally, temperature change has varied from acooling of 0.3℃ in Southwest China to a'warming of 1 .0℃ in Northeast China. With the exception of South China,all regions of China have shown a declination in precipitation. Climatic change has the features of increasing remarkably in winter temperature and decreasing obviously in summer precipitation. Under doubled CO2 concentration,climatic change in China will tend to be warmer and moister, with increases of 4.5℃ in annual mean air temperatureand 11% in annual precipitation on the national scale. Future climatic change will reduce the temporal and spatialdifferences of climatic factors.
