GAS EXCHANGE OF MICROPROPAGATED GRAPEVINE (V. VINIFERA L.) PLANTS

‘Dimiat’ and ‘Italian Riesling’ plantlets of 13th to 26th subcultures, as well as initially propagated plantlets were used.
The explants were cultured on modified MS medium with half-strength macro-salts, full-strength micro-salts and indole-3-acetic acid of 1 mg L^-1. Plant growth characteristics were determined during in vitro culture and acclimatization.
The in vitro plantlets developed well under the experimental conditions.
The ex vitro plants showed rapidly a good root system development.
Rates of photosynthesis (Pn) and dark respiration (Rd) were measured with an infra-red gas analyzer.
In the two trials conducted, four light levels were tested: 20, 100, 200 and 400 μmol m^-2 s^-1. Pn and Rd were determined at 21-23°C. During acclimatization, measurements were carried out additionally at 21°C and 26°C. Pn increased significantly with light intensity, especially from 20 to 200 mmol m^-2 s^-1. During acclimatization, the temperature enhancement by 5°C affected positively Pn only at 400 μmol m^-2 s^-1 in the second week after transfer from in vitro culture, but at all light intensities two weeks later.
Pn was not affected by the subculturing.
An increase of ambient temperature by 5°C led to a significant change in Rd during the second week of acclimatization, but only to small changes later.
Transpiration rates (E) were determined gravimetrically by means of analytical balance.
E decreased significantly with time during acclimatization.
However, E was higher for the in vitro plantlets compared to the ex vitro ones.

International Workshop on Advances in Grapevine and Wine Research

T. Slavtcheva, V. Dimitrova

grapevine, photosynthesis, dark respiration, transpiration, in vitro culture, acclimatization, light, temperature

https://doi.org/10.17660/ActaHortic.2007.754.33