Densidad estomatal y potencial hídrico en plantas de tomate (Physalis ixocarpa Brot.), propagadas por cultivo de meristemos

The husk tomato is a Solanaceous plant of Mexican origin. In Mexico, this plant can grows at wild or culture way. The in vitro propagation is an alternative for producing very much healthy plants. But some times the acclimatization has been the limiting factor to reach this objective. There are not so much reports related with husk tomato micropropagation, and this is the first where the changes on stomatal density and water potential, 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 covered with plastic covers, which were opened each seven days. Each time, the temperature and relative humidity were measured, in the acclimatization system and the growth chamber, for calculating the water potential. 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 during the acclimatization stage. Significant differences were observed at this parameter between adaxial and abaxial leaf plant and between plant ages. When both water potential and stomatal density data were related, a great correlation was observed. 100 % of the plants survived later the acclimatization stage.