Stimulatory effect of lanthanum nitrate on the root tuber yield of Pseudostellaria heterophylla via improved photosynthetic characteristics

Effects of different concentrations of lanthanum nitrate on diurnal variation of net photosynthetic rate (Pn) (a), stomatal conductance (Gs) (b), intercellular CO2 concentration (Ci) (c) and transpiration rate (Tr) (d) in P. heterophylla seedlings (Note: Different lowercase letters indicate a significant difference at 0.05 level between different treatments. CK, La 25, La 100, La 400 and La 700 represent 0, 25, 100, 400 and 700 mg/L lanthanum nitrate treatments, respectively)