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The quality of light has played an important role not only in the vegetative growth, but also in the reproductive stage of the plant. Normally, the endogenous transformation has hardly been observed under the general condition. This study analyzed the endogenous changes, which were particularly influenced by the spectrum of light emitting diode (LED) with induction flowering time from 30th to 40th day. In the 40th day of the flowering process, when the average number of flower buds get the highest, endogenous carbohydrate content was decreased. However, in this phase, plants need more energy; therefore, the net photosynthetic rate tends to increase in order to supply energy for flowering. Throughout 40 days of culture, the net photosynthetic rate had an increase in the concentration of CO2. In particular, it reached the peak when being induced under the light combination ratio 7:3 of red and blue light (0.222 µmol mol-1 h-1). The sugar content also followed the same trajectory; however, it dropped at the end of the period. Among all the experiments, the ratio of red and blue light 5:5 resulted in the highest content of endogenous carbohydrate source (722.30 µg g-1). Moreover, the morphological anatomy of shoot apical meristem in flowering stage was also studied. The floral transition at meristem and floral architecture is as similar as that of Arabidopsis. A typical flower of T. fournieri also consists of a sequence: sepals – petals – stamens – carpels. The SAM is organized into three different zones such as the central zone (CZ), the peripheral zone (PZ) surrounding the CZ and the rib zone (RZ) underneath the CZ.

Plantlets of sweet potato ( Ipomoea batatas L. ) were cultured in vitro under three different ambient conditions including a standard culture room - PS, a culture room inside a glasshouse with natural light but controlled temperature - TH, and a standard glasshouse with natural light (natural fluctuations of temperature) - NP. Plantlets from three treatments were compared in terms of pathogen rate, growth, survival plant at the end of the in vitro stage and at the ex vitro acclimatization. This result showed that, after 28 days of culture, sweet potato plants were cultured in vitro TH conditions have reduced entirely due to susceptibility to fungal disease causing outside air. After 14 days of ex vitro acclimatization, plants originally grow in vitro under the TH condition had ability to adapt about field survival and growth rates better than the other two treatments.