Chlorophyll Fluorescence as an Indicator of Photosynthetic Behaviour of In Vitro Chestnut during Acclimatization at High CO 2 Availability

In vitro propagation takes place in controlled environments regarding physical (temperature and light), hormonal, nutritional and sanitarian conditions. One of the main applications is plant clonal propagation; nevertheless, the survival rate of in vitro plantlets when transferred to in vivo can be very low. An acclimatization period, defined as the natural process where plants can adjust their physiological processes to the changing man-controlled environmental conditions is normally required. It has been reported that the manipulation of the irradiance regime gives rise to a decrease of the acclimatization period and an increase of survival rates (1). It is also possible to stimulate growth through the increase in the CO2 concentration (2, 3, 4). In the present study the use of two CO2 concentrations (350 ppm and 700 ppm) at a light intensity of 300 umol quanta m-2·s-1 during the acclimatization of in vitro chestnut was tested. Treatments were compared through growth analysis and fluorescence parameters.