This article reports the effect of growing conditions on the anatomical and ultrastructural changes associated with the development of photoautotrophy in Gardenia jasminoides Ellis plantlets during shoot multiplication in vitro. Two photosynthetic photon flux densities (PPFD) (50 and 100 μmol m−2 s−1 PPFD: L50 and L100, respectively) and two sucrose concentrations in the culture medium (5 and 30 g L−1: S5 and S30, respectively) were assayed. An increase in PPFD stimulated the development of photosynthetic tissues and led to higher photosynthesis and dark respiration regardless of the sucrose level assayed. However, the effect of sucrose in the medium depended on the PPFD. For the high‐PPFD treatment, a low sucrose concentration in the medium stimulated the development of photosynthetic tissues, whereas the opposite effect of sucrose was observed at low PPFD. This study demonstrated that an increase in light intensity to moderate values such as L100 has a beneficial effect on the development of structural changes associated with photoautotrophy. Such an effect is stimulated by low sucrose (S5) levels in the medium. These modifications of usual growing conditions (such as L50 combined with S30) for micropropagation may prove to be useful in mass propagation of gardenia. However, the use of a low sucrose level in addition to conventional growing PPFD may be counterproductive.

中文翻译：

---

光照和蔗糖水平对栀子体外培养的解剖学、超微结构和光合作用的影响

本文报告了生长条件对栀子幼苗在体外枝条增殖过程中光能自养发展相关的解剖学和超微结构变化的影响。两种光合光子通量密度 (PPFD)（分别为 50 和 100 μmol m-2 s-1 PPFD：L50 和 L100）和培养基中的两种蔗糖浓度（分别为 5 和 30 g L-1：S5 和 S30）进行了测定。PPFD 的增加刺激了光合组织的发育，并导致更高的光合作用和暗呼吸，而不管测定的蔗糖水平如何。然而，培养基中蔗糖的影响取决于 PPFD。对于高 PPFD 处理，培养基中的低蔗糖浓度刺激了光合组织的发育，而在低 PPFD 下观察到蔗糖的相反效果。该研究表明，将光强度增加到中等值（如 L100）对与光合自养相关的结构变化的发展具有有益影响。这种效果是由培养基中的低蔗糖 (S5) 水平刺激的。这些用于微繁殖的通常生长条件（如 L50 与 S30 结合）的修改可能被证明在栀子的大规模繁殖中是有用的。然而，除了传统的生长 PPFD 之外，使用低蔗糖水平可能会适得其反。这种效果是由培养基中的低蔗糖 (S5) 水平刺激的。这些用于微繁殖的通常生长条件（如 L50 与 S30 结合）的修改可能被证明在栀子的大规模繁殖中是有用的。然而，除了传统的生长 PPFD 之外，使用低蔗糖水平可能会适得其反。这种效果是由培养基中的低蔗糖 (S5) 水平刺激的。这些用于微繁殖的通常生长条件（如 L50 与 S30 结合）的修改可能被证明在栀子的大规模繁殖中是有用的。然而，除了传统的生长 PPFD 之外，使用低蔗糖水平可能会适得其反。