Background : Management of air temperature are known to primarily affecting on physiological properties and yield in plant. Methods and Results : The effect of air temperature on characteristics of photosynthesis and chlorophyll fluorescence in Cnidium officinal were investigated using growth chamber after cultivating for 24 hours under controlled condition. Net photosyntheis rate, transpiration was measured at 1,000 μmol m-2 s-1 of photon flux density and chlorophyll fluorescence was analyzed by OJIP method. Net photosyntheis rate was highest in treatment of 25℃. Although transpiration rate was lowest, water use efficience was also in treatment of 25℃. Stomatal conductance was mainly influenced from ambient climatric factors such as vapor pressure deficit. As results of chlorophyll fluorescence by OJIP analysis, maximum quantum yield (Fv/Fm) of photosystem II (PSII), PIabs and the relative activities per reaction center such as ABS/RC, DIo/RC were not changed at air temperature. Therefore, elevated air temperatue during short term influence the dark reaction in photosystem through controlling a water use efficience and transpiration. Conclusion : This result show that 25℃ of air temperature may be a adequate temperature to improving the efficiency of photosynthesis in Cnidium officinale.

• Young Jin Seo(Bonghwa Herbal Crop Research Institute, Gyeongsangbuk-do Agricultural Research and Extention Services) | 서영진 Corresponding author
• Hyo Hoon Nam(Bonghwa Herbal Crop Research Institute, Gyeongsangbuk-do Agricultural Research and Extention Services) | 남효훈
• Beung Sung Kim(Bonghwa Herbal Crop Research Institute, Gyeongsangbuk-do Agricultural Research and Extention Services) | 김병성
• Yae Young Oh(Bonghwa Herbal Crop Research Institute, Gyeongsangbuk-do Agricultural Research and Extention Services) | 오태영
• Jong Soo Kim(Bonghwa Herbal Crop Research Institute, Gyeongsangbuk-do Agricultural Research and Extention Services) | 김종수