Effects Of Temperature And CO₂ On Physiological,Biochemical And Stomatal Characteristics Of Fruit Corn

Global warming has become an indisputable fact,and it is most obvious that the temperature and CO₂ is increasing.This affects the structure of the entire ecosystem and changes in plant physiology.Temperature and CO₂ on the one hand affect the balance of the entire ecosystem,on the other hand interfere with plant growth and yield.In this paper,fruit corn,variety of Wantian 2000,was planted in a flowerpot with a diameter of 25 cm at room temperature.The soil was made of 6:4 culture soil and loess.After 15days the flower pots were moved to artificial climate chambers at a temperature of 30?and the climatic chamber culture conditions were adjusted one week later.CO₂ concentrations were set to 400 ppm and 800 ppm,and the temperatures were set to 30?,35?,40?and 45?,repeated three times.The effects of temperature and CO₂ concentration on the leaf and physiological characteristics of fruit corn were studied,including the changes of leaf stoma characteristics,biomass,chlorophyll fluorescence parameters and the photosynthesis,transpiration,stoma conductance,CO₂ concentration and leaf temperature.The main conclusions of this paper:?1?The effects of temperature and CO₂ on stoma characteristics of fruit corn were studied.When CO₂ was constant,stoma density,stoma index and stoma width increased,while stoma length decreased with temperature from 30?to 40?.The increase rates of stoma density,stoma index and stoma width decreased gradually and the stoma length decreased with temperature from 40?to 45?.When temperature was constant,with CO₂ increasing,stoma density and stoma index increased,but stoma width,stoma length,stoma area and stoma circumference decreased.?2?The effects of temperature and CO₂ on biomass of fruit corn were studied.Under the condition of CO₂ at 400ppm,the plant height of fruit corn reached the highest value at 40?,and the plant height was lowest at 30?with the increase of temperature.Under the condition of CO₂ at 800ppm,fruit corn plant height increased with increasing temperature,and plant height at 45?was significantly higher than other treatments.Stems thick was the largest at 40?.?3?The effects of temperature and CO₂ on the chlorophyll fluorescence parameters of fruit corn were studied.Under the condition of CO₂ at 400ppm,F₀,Fm,F_v/F₀ and Fv/Fm increased first and then decreased with increasing temperature,reaching the maximum at 35?.Under the condition of CO₂ at 800ppm,F_m,F_v/F₀ and F_v/F_m showed an upward trend with the increase of temperature,while F₀ showed a downward trend.At constant temperature,F₀ showed a decreasing trend but F_m,F_v/F₀and F_v/F_m showed an upward trend with CO₂ from 400ppm to 800ppm.?4?The effects of temperature and CO₂ on the physiological characteristics of fruit corn were studied.Under the condition of CO₂ at 400ppm,the net photosynthetic rate,transpiration rate,intercellular CO₂ concentration and leaf temperature increased and the stoma conductance increased first and then reduced,reaching the maximum at40?with the increase of temperature.Under the condition of CO₂ at 800ppm,the net photosynthetic rate and transpiration rate showed a downward trend,and the stoma conductance,intercellular CO₂ concentration and leaf temperature tended to first increase and then decrease,reaching the maximum value at 40?and the largest leaf temperature at 35?with the increase of temperature.When the temperature was between 30?to 40?,the net photosynthetic rate,transpiration rate,intercellular CCO₂ concentration and leaf temperature increased,and the stoma conductance decreased with CO₂ concentration increasing.When the temperature was 45?,the net photosynthetic rate,transpiration rate,intercellular CO₂ concentration,leaf temperature and stoma conductance all decreased,with CO₂ concentration increasing.