The Effect Of Photosynthetic Physiology, Yield And Quality Of Rape To Increasing CO₂ Concentration

The experiment on rape in two CO2 concentration(550μmol·mol-1,750μmol·mol-1) treatments is made by using the Open-top chamber.Natural environment, atmospheric CO2concentration is compared. I study the changes and differents of plant height, leaf area, photosynthesis physiological, yield and quality of the rape. I explore the trend of growth,the development, physiological characteristics ,yield and quality of the rape on the condition of different CO2 concentration . Researching shows :(1)the height of rape is increasing with the increasing of atmospheric CO2 concentration. compared the effect of concentration of CO2 (365μmol ? mol-1 )treatment with the effect of two high CO2 concentration(550μmol·mol-1,750μmol·mol-1) , rape height increased 1.25% -7.83%,rape Leaf area of flowering rape increased 13.61%, and 37.41%. The rape photosynthetic rate, water use efficiency are promoted And transpiration rate and stomatal conductance is reduced on the condition of atmospheric CO2 concentration Increased.with increasing concentration of CO2. compared the effect of concentration of CO2 (365μmol?mol-1 )treatment with the effect of two high CO2 concentration(550μmol·mol-1,750μmol·mol-1) , photosynthetic rate of rape is increased by 15.48% -59.6%. Rape water use efficiency is improved by 30.25% -105.66%. Rape stomatal conductance is decreased by 2.63% -10.23%. Rape transpiration rate is decreased by 8.27% -22.79%.(2)On the condition of low CO2 concentration (365μmol ? mol-1) treatment, the lunch break situation of rape photosynthetic rate is appearing in one day. However, with the increasing of CO2 concentrations, the lunch break situation of rape photosynthetic rate is eased until disappearance; with atmospheric CO2 concentration increased, the photosynthetic rate of rape and water use efficiency which have varying degrees of improve in the day: Rape photosynthetic rate is increases for 4.49% -55.47%, water use efficiency is improved by10.11%-115.44%; Rape of stomatal conductance and transpiration rate are decreased to varying degrees with the rise of atmospheric CO2 concentration in one day: Transpiration rate is decreased by of 5.1% -27.87 %. The stomatal conductance of rape is decreaseed by 2.24%-27.97%.(3)With the concentrations of atmospheric CO2 increasing, chlorophyll a, chlorophyll b, and Total chlorophyll content of rape showes a trend of increasing. compared the effect of concentration of CO2 (365μmol ? mol-1 )treatment with the effect of two high CO2 concentration(550μmol·mol-1,750μmol·mol-1) , chlorophyll a content of the bolting stage of rape increase of 3.31 percent and 8.56 percent. The content of Chlorophyll b in the bolting stage of rape increase 6.88% and 13.76%. Total chlorophyll content increases of 3.27% -5.18%. With the concentrations of atmospheric CO2 increasing, chlorophyll b increasing ration of rape is bigger than the increase ration of chlorophyll a .therefore, the ratio of chlorophyll b and chlorophyll a is reduced.(4)With the concentrations of atmospheric CO2 increasing, the total number pod of rape, yield per plant, grain weight and oil content showed an upward trend. compared the effect of concentration of CO2(365μmol?mol-1)treatment with the effect of two high CO2 concentration(550μmol·mol-1,750μmol·mol-1) , rapeseed yield per plant increased by 13.78% and 30.69%, oil content increased by0.76% -1.6%. Elevated the atmospheric CO2 concentration effects to the rape production and the constitues factors of rape production, The most notably factor is total number of rape per pod, followed by one thousand rapeseed weight, the smallest notably factor is the number of pods per plant. Rapeseed grain nutritional elements decline with higher concentrations of atmospheric CO2, such as phosphorus potassium, iron and other elements .The largest decrease is iron. compared the effect of concentration of CO2 (365μmol ? mol-1 )treatment with the effect of two high CO2 concentration(550μmol·mol-1,750μmol·mol-1) .The element of Fe is decreased by 4.16% -9.56%. Zinc, selenium and manganese element of rapeseed is increase with the atmospheric CO2 concentration increased. Various elements increasing ration is different sizes. The largest increases are manganese. The other elements of rape had no significant change in trend.(5)Rapeseed protein content is declined with the concentration of atmospheric CO2 increased. compared the effect of concentration of CO2 (365μmol ? mol-1 )treatment with the effect of two high CO2 concentration(550μmol·mol-1,750μmol·mol-1), rapeseed protein content decreased by 0.74% and 1.37%. compared the effect of concentration of CO2 (365μmol ?mol-1 )treatment with the effect of two high CO2 concentration(550μmol·mol-1,750μmol·mol-1), the amino acid components of rapeseed grains generally show a downward trend. The bigger drop is L-tryptophan, sulfur acid and serine. The smaller decrease is leucine, alanine and lysine. The other 12 kinds of amino acids have varying degrees of decline. With the CO2 content increasing, Amino acids also showed a downward trend. The majority of 8 kinds amino acids of the human body must be content show a downward trend,but methionine content is mixed and threonine content have no significant changes in trends. This will have a negative impact to some extent on the quality of rape.