Resumo

BAZALDUA-MUNOZ, C. et al. Stomatal density and water potential on husk tomato (Physalis ixocarpa Brot.), micropropagated by mean of meristem culture. Rev. Chapingo Ser.Hortic [online]. 2008, vol.14, n.2, pp.147-152. ISSN 2007-4034.

Husk tomato is a Solanaceous plant from Mexico, this plant can grow wild or cultivated. In vitro propagation is an alternative for mass production of pathogen free plants. But some times acclimatization has been the limiting factor to reach this objective. Few reports related with husk tomato micropropagation are found, and this is the first one kwnown to us where the changes on stomatal density and water potential and plantlets obtained from apical meristems during the acclimatization, are evaluated. That evaluation was done during the acclimatization from plantlets obtained by mean of apical meristem culture. Plants of 30 days old with similar size were placed in individual hydroponics system, during seven weeks, all of them with plastic covers, which were gradually opened each seven days. Each time, the temperature and relative humidity were measured, in the acclimatization system and the growth chamber, for water potential estimation. At the sixth week, the water potential in the acclimatization system was close to that of the growth chamber (-107.8 and -102.2 ± 4.91 respectively). On the other hand, the stomatal density was evaluated at 15, 30 and 45 days of the acclimatization stage. Significant differences were observed at this parameter between adaxial and abaxial leaves surfaces, and between different plant ages. When both, water potential and stomatal density data were compared, a great correlation was observed. A 100% of the plants survived the acclimatization period.

Palavras-chave : acclimatization; stomatal density; water potential; micropropagation; Physalis ixocarpa Brot.