Photosynthesis response of the potato leaves of root-vegetable type and leaf-vegetable type to light and CO2 concentration

Photosynthesis response of the potato leaves of root-vegetable type and leaf-vegetable type to light and CO2 concentration, using a gas analyzer Li-6400, were measured. The results showed that the maximum photosynthetic rate (Pmax), light saturation point (LSP),light compensation point (LCP) and the respiration rate in the light (Rn) of root-vegetable type were all higher than that of leaf-vegetable type. As the same, the maximum carboxylation rate of root-vegetable type was also higher than that of leaf-vegetable type. The rate was 34.168(Honghong No.1)，44.448 (Zheshu 13)，27.244(Zhecaishu 726) and 30.617(Shulu No. 1) μmol/m2.s, respectively. The transpiration and stomatal conductance of root-vegetable type were also higher than that of leaf-vegetable type. While water use efficiency and stomata limitation value were highest in Shulu No. 1。