ISHS Acta Horticulturae 812: III International Symposium on Acclimatization and Establishment of Micropropagated Plants
ACCLIMATIZATION OF DORITAENOPSIS HYBRID ORCHIDS AS AFFECTED BY PPF LEVELS |
| Authors: | E.-J. Hahn, M.-W. Jeon, E.-J. Lee, K.Y. Paek |
| Keywords: | acclimatization, Doritaenopsis, photosynthetic photon flux, photoinhibition |
| Abstract:
Doritaenopsis orchids ‘New Candy’ were propagated in vitro for 3 months and transferred to ex vitro for acclimatization under different PPF levels: 50, 100, 150, 200, and 300 μmol m-2 s-1. Leaf RWC started to decrease at all PPF levels, which was significant under high PPFs (200 and 300 μmol m-2 s-1) especially until 5 days of acclimatization. Little changes were observed at low PPFs (50, 100 and 150 μmol m-2 s-1), showing higher leaf RWC after 30 days of acclimatization compared with high PPF levels. Changes of Fv/Fm value were similar to those of leaf RWC. High PPFs (200 and 300 μmol m-2 s-1) induced rapid decreases of FV/Fm in the plantlets after 2 days of acclimatization, which were recovered from the 5th day but the FV/Fm value was lower than that under low PPFs (50, 100 and 150 μmol m-2 s-1) until the end of acclimatization period. PPF levels also affected growth responses of the plantlets. Low PPFs (50, 100 and 150 μmol m-2 s-1) resulted in higher growth and survival rate, while high PPFs (200 and 300 μmol m-2 s-1) inhibited them. Especially, plantlet growth was severely suppressed at 300 μmol m-2 s-1 and as a result plantlet survival rate reached only 75%. The results suggested that physiological acclimatization occurs at 100 and 150 µmol m-2 s-1, which was correlated with a photosynthetic compensation point for Doritaenopsis hybrid orchids. | |
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