INFLUENCE OF NUTRITIONAL AND ENVIRONMENTAL FACTORS ON PRODUCTIVITY AND PHOTOAUTOTROPHY OF TRANSPLANTS IN VITRO

The influence of the sucrose concentration on in vitro photosynthesis, assimilate deposition and in vitro root formation was investigated with decreasing sucrose supply in the medium. The CO₂-uptake of Vitis plants increased and the rooting intensity improved. Blue light stimulated chlorophyll synthesis but the light response curves of in vitro rooted oaks to red and white irradiation exceeded the blue light spectrum. The glucose, fructose and sucrose contents varied according to light and dark exposures showing the differences between heterotrophic and photoautotrophic metabolism. The CO₂-enrichment in vitro and ex vitro for the improvement of the photoautotrophy is discussed. The number of stomata per leaf area in vitro can be higher than ex vitro; the leaf area in vitro is altered in dependence on air exchange between the culture vessel and ambient atmosphere.