Fig. 1
Seasonal variations in leaf morphological and physiological traits variables (means±SD; n = 4–6) of P. volubilis plants in response to defoliation and defloration. Significance levels of ANOVAs testing for the effects of season (S), treatment (T) and their interaction are listed for each variable. The values with different letters within the same season denote significant difference between different treatments at P < 0.05 level. CK, control; ns, no significance. *P < 0.05; **P < 0.01; ***P < 0.001. SLA, specific leaf area; Pn, net light-saturated photosynthetic rate; gs, stomatal conductance; WUEi, intrinsic water-use efficiency; PNUE, photosynthetic N-use efficiency