Microclimate in tissue culture vcssels and its physiologicaleffects on plantlcts

Understanding the environmental conditions in vessels of tissue cultured plantlets could help us to prepare optimum conditions, and hence improve the production efficiency in micropropagation. Plantlets of wild cherry were studied in culture vessels, using two different types of caps, conventional non-vented cap (NYC) and filtered vented cap (YC). CO2 concentrations in vessels, in general, were lower, compared with atmospheric CO2, but more reduction in concentration was observed in NYC. When the light intensity was increased, more depletion of CO2 in the vessels was measured. However, no significant differences in photosynthetic performance (Pm) were observed in plantlets under two treatments. Transpiration rate and stomatal conductance of plantlets in VC were lower and this could be due to improvement in stomatal functioning. This improvement, in turn, has been attributed to lower relative humidity (RH). In this experiment RH in YC vessels was 17% lower than NYC.