Photosynthetic response of Podophyllum hexandrum Royle from different altitudes in Himalayan ranges.

Plants of Podophyllum hexandrum, collected from lower, mid, and upper distribution limits in alpine Himalaya were studied under greenhouse conditions to evaluate the photosynthetic response. Net photosynthetic rates (PN), stomatal conductance (gs), and efficiency of carbon uptake increased with altitude. The maximum PN and gs were measured in the considered population during the 3–6th week of development. PN and gs decreased on an average by 58 and 48 % from maximum rates reached around 4th week to the 10th week of growth, respectively. The photosynthetic response in the three ecotypes appeared to be genetically controlled