title: [Comparative study on photosynthetic characteristics of different ploidy Rhodiola sachalinensis germplasm].
abstract: OBJECTIVE
  To compare the photosynthetic characteristics difference of different ploidy Rhodiola sachalinensis germplasm and provide the scientific basis for their cultivation.
  
  
  METHODS
  LI-6400/XT photosynthesis system was used to measure leaf light response curve and CO2 response curve of diploid and autotetraploid. Biomass, leaf area, stomatal characteristics and chlorophyll content differences were compared in the study.
  
  
  RESULTS
  Stomata of the two germplasms were open during daytime obviously, and stomata conductance responded to the changes of light intensity and CO2 concentration which was not consistent with the characteristics of CAM (crassulacean acid metabolism) plants. Light compensation point of autotetraploid was significantly lower than that of the diploid, and light saturation points of both germplam were close, and their light saturation points were near 500 micromol x m(-2) x s(-1). Quantum efficiency of autotetraploid was significantly higher than the diploid, and the net photosynthetic rate of autotetraploid significantly higher than the diploid when light intensity was higher than 500 micromol x m(-2) x s(-1). Stomata conductance, transpiration rate of autotetraploid was also significantly higher than that of diploid. Biomass, leaf area, stomata diameter and chlorophyll content of autotetraploid were much higher than that of diploid, while the stomata density of autotetraploid was less than diploid.
  
  
  CONCLUSIONS
  The results above provide scientific basis for the cultivation of different ploidy Rh. sachalinensi germplasm.
authors: Jilin Normal University, Siping 136000, China. jianfengliu1976@163.com
authors: Jianfeng
authors: J
authors: Liu
authors: Yunqing
authors: Y
authors: Cheng
authors: Chunming
authors: C
authors: Liu
authors: Kun
authors: K
authors: Yan
authors: Xiaofu
authors: X
authors: Zhou
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism; D010788:Photosynthesis / Q000502:physiology*; D011003:Ploidies; D029771:Rhodiola / Q000378:metabolism*
chemical_list: D002245:Carbon Dioxide