Photosynthesis, stomatal conductance and leaf water potential characteristics were examined in two plantago species (Plantago ovata Forssk and P. psyllium L.), with gradually improving water stress for several days and permitting to recover by re-watering (withholding for 2, 4, 6, 8 and 10 days) in Melbourne University in 2006. Factorial experiments based on completely randomized design with four replications were used. The photosynthetic rate and stomatal conductance decreased rapidly by withholding water. After re-watering the recovery rate of photosynthesis and stomatal conductance decreased gradually, as the days became longer. The different rates of recovery of photosynthesis and stomatal conductance followed by drought stress. However, the potentional of photosynthesis recovery was more than stomatal conductance. It is also concluded that French psyllium had higher mesophyl and stomatal conductance recovery when compared to Isabgul, although recovery of photosynthesis in Isabgul was higher than French psyllium. The results showed a clear and close correlation between leaf water potential and recovery level of photosynthesis rate and stomatal conductance. A close correlation was also observed between photosynthesis and leaf water potential, stomatal conductance and relative water content.


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