INFLUENCE OF LIGHT QUALITY ON IN VITRO PHOTOSYNTHESIS, LEAF MORPHOMETRY, LEAF ANATOMY AND FIELD PERFORMANCE IN MICROPROPAGATED BETULA PENDULA ROOTH.

A. Sæbø, T. Krekling, M. Appelgren
Experimental light environments were established in six growth rooms, using commercially available light sources. Eight top or nodal micro cuttings were grown on WPM medium in glass vessels with 0.3 mg/l BAP. The plantlets were treated for five weeks with 11 different light qualities.

Photosynthesis was recorded as μmol CO2 consumption per hour per dm2 leaf area, or per hour per mg chlorophyll per dm2 leaf area. CO2 was supplied to the modified tissue culture vessel, which was used as cuvette, so that CO2 concentration at recording was kept at 340–370 ppm. Plants were kept on the same medium at recording of photosynthesis as when treated with different light qualities in vitro. Material for microscopy was collected at the same time as recording of photosynthesis.

Photosynthetic ability was best in the plantlets subjected to light high in blue wave bands, compared to plantlets treated with red light, or light high in both red and far-red. Total leaf area per leaf was largest in cultures treated with either blue or red + far-red light, and lowest in cultures subjected to red light, which had neither blue nor far-red light. Leaves treated with blue light had the highest ratio of palisade tissue: spongy mesophyll tissue, compared to leaves subjected to light high in red + far-red light, which had the lowest ratio.

When testing field performance after in vitro treatments, plants subjected to light sources with output in both blue and red light performed best. Plants subjected to light from incandescent lamps grew at significantly lower rates than plants from other treatments.

Light quality to in vitro cultured plants influence both morphology and physiology of the plantlets. Light quality can thus be used to affect the development of the plantlets in vitro, and for some species also the growth and morphology of the plants after transfer to in vivo conditions.

Sæbø, A., Krekling, T. and Appelgren, M. (1992). INFLUENCE OF LIGHT QUALITY ON IN VITRO PHOTOSYNTHESIS, LEAF MORPHOMETRY, LEAF ANATOMY AND FIELD PERFORMANCE IN MICROPROPAGATED BETULA PENDULA ROOTH.. Acta Hortic. 327, 97-98
DOI: 10.17660/ActaHortic.1992.327.12
https://doi.org/10.17660/ActaHortic.1992.327.12