Abstract
Grafted tomato (Lycopersicon esculentum Mill.) plug seedlings were stored at 10°C for 21 d under a photosynthetic photon flux density (PPFD) of 2 ymol m-2 s-1 using mixed light from red and blue LEDs, with different percentages of blue-light PPFD (0, 2, 5, 10 and 50%) . The effect of blue-light PPFD percentage was investigated and the optimal percentage was determined based on the contents of chlorophyll (Chl) and ribulose-l, 5-bisphosphate carboxylase/oxygenase (Rubisco) in leaves on the last days of storage. Chl and Rubisco contents decreased irrespective of the blue-light treatment during storage. On the last day of storage, Chl content were greater in the 2, 5, and 50% blue-light treatments than in the 0% treatment and Rubisco content were greater in the 2-50% treatments than in the 0% treatment. The suppression of the decrease in the Chl content contributed to the preservation of the visual quality of the stored seedlings. It can be concluded that the 2, 5 and 50% blue-light PPFD were effective in preserving the quality of grafted tomato seedlings during storage at 10°C and 2, umol m-2 s-1. In a commercial operation, 2% blue-light PPFD would be optimal, because blue LEDs are expensive.
