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

摘要

P. hexandrum plants collected from lower, mid and upper distribution limits in alpine Himalaya (Great Himalayan National Park, Kukumseri and Koksar in Himachal Pradesh, India) were studied under greenhouse conditions to evaluate photosynthetic response. Net photosynthetic rates (PN), stomatal conductance (gs), and efficiency of carbon uptake increased with altitude. The highest PN and gs were measured from the 3rd to the 6th week of development. PN and gs decreased by an average of 58 and 48%, respectively, from maximum rates reached around the 4th to the 10th week of growth. The photosynthetic response in the 3 ecotypes appeared to be genetically controlled..