Chin J Plant Ecol ›› 2008, Vol. 32 ›› Issue (3): 654-663.DOI: 10.3773/j.issn.1005-264x.2008.03.015

• Original article • Previous Articles     Next Articles

SALT RESISTANCE OF TETRAPLOID ROBINIA PSEUDOACACIA

MENG Fan-Juan1, WANG Qiu-Yu1, WANG Jian-Zhong2,*(), LI Shu-Yan2, WANG Jiang-Jiang1   

  1. 1College of Life Sciences, Northeast Forestry University, Harbin 150040, China
    2School of Biological Science and Biotechnology, Beijing Forestry University, Beijing 100083, China
  • Received:2007-11-05 Accepted:2008-01-13 Online:2008-11-05 Published:2008-05-30
  • Contact: WANG Jian-Zhong

Abstract:

Aims Our objective was to compare tetraploid vs. diploid Robinia pseudoacacia for salt stress effects on their morphology, physiology, physiobiology, photosynthesis and anatomy.

Methods We grew tetraploid and diploid R. pseudoacacia treated four times with two salts, NaCl and Na2SO4, and untreated diploid R. pseudoacacia as a control. After 30 days, we examined them every 7 days.

Important findings The growth of diploid R. pseudoacacia was restrained, its water content and chlorophyll content had obvious differences to the control, and salt injury was eventually observed. The water content and chlorophyll content of tetraploid R. pseudoacacia had no obvious differences to the control, and salt injury was not observed. Relative REC (Relative conductivity) and Pro (Proline) activity of tetraploid R. pseudoacacia increased slightly, but were not different from the control. Relative REC and Pro activity in treated diploid R. pseudoacacia were higher than the control. The protective systems of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) retained higher activity at late periods in tetraploid R. pseudoacacia under salt stress, which contributed to salt tolerance, but they retained lower activity in treated diploid R. pseudoacacia. Photosynthesis in tetraploid R. pseudoacacia was not affected by salt stress, as net photosynthetic rate (Pn) and intercellular CO2 concentration (Ci) were unchanged, but changes did occur in diploid R. pseudoacacia. The leaf anatomy of tetraploid R. pseudoacacia changed, e.g., palisade cells were longer and more densely packed and spongy mesophyll cells were more densely packed. Based on these findings, tetraploid R. pseudoacacia had stronger salt tolerance.

Key words: tetraploid Robinia pseudoacacia, diploid R. pseudoacacia, salt stress, salt resistance