Figure 10.

Principal component analysis of morphological and physiological indexes under different planting densities. AQY, the maximum apparent quantum yield; PPDF_max, PPDF_med, and PPDF_AV represent the maximum, median, and average value of light intensity, respectively; P_nmax and P_nmed represent the maximum and median net photosynthetic rate, respectively; PC, principal component; T_{(PPDF > 200)}, T_{(PPDF > 400)}, T_{(PPDF > 800)}, and T_{(PPDF > 1200)} represent the duration of high light when the light intensity was higher than 200, 400, 800, and 1,200 μmol m⁻² s⁻¹, respectively. T_{Pn (PPDF > 200)}, T_{Pn (PPDF > 400)}, T_{Pn (PPDF > 800)}, and T_{Pn (PPDF > 1200)} represent the duration of photosynthesis when the light intensity was higher than 200, 400, 800, and 1,200 μmol m⁻² s⁻¹, respectively.