Photosynthesis of Celosia Cristata with Different Heat Tolerance

To explore the relationship of photosynthesis between Celosia cristata with different heat tolerance,leaves of century green(heat tolerant) and century copper(heat sensitive)are chosen to study their photosynthetic functions at high temperature in the open air.The results show that the diurnal variation of photosynthetic rate(Pn)and photosynthetic active radiation make a single peak curve,with similar and synchronous change pattern.Photosynthetic rate(Pn)has a positive correlation to photosynthetic active radiation,which is characteristic of heliophilous plant.The photosynthetic rate(Pn)of century green is lower than the heat century copper.Stomal conductance,photosynthetic rate(Pn),transpiration rate,photosynthetic active radiation and intercellular CO2 concentration show positive correlation.At 12o’clock,with strong light and higher leaf temperature,the heat century green can keep higher photosynthetic rate(Pn)in a wide range.The light compensation point and light saturation point of variety-century green is significantly higher than that of century copper.Their light saturation point were 1500 μmol.m-2.s-1 and 1000 μmol.m-2.s-1,Light compensation point are 39.3 μmol.m-2.s-1 and 37.1 μmol.m-2.s-1.While CO2 saturation point are 1000 μmol/mol and 850 μmol/mol,CO2 compensation point are112 μmol/mol and 100.3μmol/mol.These results provide theoretical basis for the rational cultivation of celosia cristata.