Effects of light and ventilation on physiological parameters during in vitro acclimatization of Gevuina avellana mol.

The effects of increased photon flux (100 μmol m s), ventilation, and standard in vitro culture (40 μmol m s) with no ventilation were investigated on the physiological and histological characteristics of microshoots of Gevuina avellana. The increase in photon flux (light treatment) produced significant improvement in the fluorescence parameters of photochemical quenching, non-photochemical quenching, electron transport rate and photochemical efficiency of PSII, compared to the ventilation and control treatments. Nursery plants showed similar values compared to the microshoots in the light treatment, indicating that the plants in the light treatment developed a management for dissipating excess light. Moreover, chlorophyll a and b concentrations increased significantly in both light and ventilation treatments. The chl a/chl b ratio decreased in the ventilation treatment compared to the control treatment. Similar results were found for soluble carbohydrates. Finally, both the photon flux increase and ventilation had a positive effect on foliar anatomy, showing a more organized mesophyll and a better development of the palisade mesophyll compared to the control treatment. The changes observed in the microshoots with regards to foliar anatomy and photochemical behavior were very similar to nursery plants. [ABSTRACT FROM AUTHOR]