Factors influencing seed germination of Salsola affinis (Chenopodiaceae), a dominant annual halophyte inhabiting the deserts of Xinjiang, China

摘要

Salsola affinis is a dominant annual inhabiting saline deserts of Xinjiang, China. Experiments were conducted to determine the effects of temperature, winged perianths and NaCl on seed germination and on germination recovery from the effects of saline conditions after transfer to distilled water. Freshly harvested seeds could germinate equally well in light and darkness at 5-30 degrees C. Attached winged perianths significantly inhibited germination, removal enhanced germination. However, germination was not inhibited in the presence of detached winged perianths in any of the temperature treatments. We suggest that the winged perianth is a mechanical barrier for radicle emergence, not a barrier for water uptake; hence, it inhibited germination. Germination of seeds from which the perianth had been removed was not affected by NaCl at concentrations below 0.4 mol/l, but it was significantly decreased by NaCl at concentrations of 0.6-2.0 mol/l. No seeds germinated at 4.0 mol/l NaCl. Seeds incubated in NaCl at concentrations of 0.05-4.0 mol/l for 14 days recovered after being transferred to distilled water. However, germination was lower than that in the non-saline control, indicating that a portion of the NaCl-treated seeds may lose their ability to germinate. (C) 2008 Elsevier GmbH. All rights reserved.