| heal.abstract |
Quercus euboica Pap., a rare, endangered oak species of Greece, that can be used as an ornamental plant, has been successfully propagated in vitro. In the present study the effect on the physiological characteristics of the microplantlets of a) different types of covering material (plastic caps, metallic caps or plastic wrap) of culture vessels, b) photosynthetic photon flux density (PPFD 25 or 50 μmol m-2 s-1) during culture and c) addition of CO2 inside the vessels (up to 1000 ppm), was examined. Data concerned the ratio between the dry and the total weight of the leaves, the chlorophyll content of the plantlets, the CO2 and ethylene concentration inside the vessels and the rate of the water loss from the in vitro growing leaves. The highest level of leaf chlorophyll content was observed in vessels covered with plastic wrap. Addition of CO2, resulted in higher chlorophyll content in leaves grown under high PPFD, but lower under low PPFD. High PPFD reduced the chlorophyll content of all leaves. Covering the vessels with plastic wrap or culture under high PPFD increased the ratio of dry to total weight of leaves, while the addition of CO2 did not improve it. CO2 addition, independently of PPFD, decreased ethylene concentration in vessels covered with plastic caps and increased it in vessels covered with plastic wrap. Covering the vessels with plastic caps in combination with culture under high PPFD and no addition of CO2 caused a dramatic reduction of the CO2 concentration inside the vessels. Covering the vessels with plastic wrap did not affect gas concentration inside the vessels. Finally, leaves excised from plants grown under plastic wrap showed lower rate of water loss than leaves from plants grown under the other covering materials. © ISHS 2013. |
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