3.2. Palisade parenchyma and spongy parenchyma
Light, especially the light intensity, seemed to positively
affect the leaf structure of the palisade parenchyma and spongy
parenchyma (Table 3, Fig. 1). The leaves under the 50 mol m−2 s−1
presented imperfect development of the palisade parenchyma,
and a more compact and clear structure of the palisade cells was
observed under other treatments. The leaf thickness, length of palisade
cells and parenchyma cells were bigger in the seedlings grown
under 300 and 450 mol m-2 s-1. There was no significant different
in leaf structure between 300 and 450 mol m−2 s−1.When PPFD
increased from 50 to 300 mol m−2 s−1, the thickness of the leaf
blade, palisade cells and parenchyma cells increased. However, the
seedlings grown under the high PPFD of 550 mol m−2 s−1 exhibited
shorter mesophyll cells (Table 3, Fig. 1F).