Fan Yang , Ling-Feng Miao

Adaptive responses to progressive drought stress in two poplar species originating from different altitudes

Yang F., Miao L.-F. (2010). Adaptive responses to progressive drought stress in two poplar species originating from different altitudes. Silva Fennica vol. 44 no. 1 article id 160. https://doi.org/10.14214/sf.160

Abstract

Cuttings of Populus kangdingensis C. Wang et Tung and Populus cathayana Rehder, originating from high and low altitudes in the eastern Himalaya, respectively, were examined during one growing season in a greenhouse to determine the effects of progressive drought stress. The results manifested that the adaptive responses to progressive drought stress were different in these two species from different altitudes. Significant changes in stem height, leaf development, relative water content (RWC), malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) appeared earlier in P. cathayana than in P. kangdingensis, whereas changes in soluble protein, soluble sugar, free proline and antioxidant enzymes appeared earlier in P. kangdingensis. In addition, changes in these parameters became more and more significant when the drought stress progressed, especially under severe drought stress in P. cathayana. Plant growth showed significant positive correlations with soluble proteins and sugars, free proline and antioxidants and a significant negative correlation with RWC under water stressed treatment in two poplar species. Compared with P. cathayana, P. kangdingensis was able to maintain a superior height growth and leaf development under drought stress. Also, P. kangdingensis possessed greater increments in soluble protein, soluble sugar, free proline and antioxidant enzymes, but lower increments in MDA and H₂O₂ than did P. cathayana when the cuttings were exposed to progressive drought stress. Our results suggest that P. kangdingensis originating from the high altitude has a better drought tolerance than does P. cathayana originating from the low altitude. Furthermore, this study manifested that acclimation to drought stress are related the rapidity, severity, duration of the drought event and the altitude of two poplar species.

Keywords
antioxidant enzymes; drought stress; free proline; hydrogen peroxide; malondialdehyde; Populus

Received 12 February 2009 Accepted 11 February 2010 Published 31 December 2010

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