Seed germination of Atriplex undulata under saline and alkaline conditions

Abstract

In this study the germination response of seeds of Atriplex undulata (Chenopodiaceae), a native of Argentina, to saline and alkaline conditions was evaluated. This species has potential as a rehabilitation crop for saline soils and is used as salt land pasture. The study involved three aspects: (1) germination response to three temperature regimes (20, 25 and 30 C); (2) the effects of saline (NaCl) and alkaline (Na2CO3) stresses, osmotic potential(0, -1, -2 MPa) and the removal of the bracteole on germination; (3) the recovery of germination with and without the bracteole following exposure to a high level of alkalinity and salinity stress. The best germination temperature was 20°C. There were no significant differences in the response to salt and alkali treatments. Seeds failed to germinate at -2 MPa, while -1 MPa reduced germination, more so for the seeds with the bracteole removed. After a pre-treatment with salt or alkali stress, seeds exposed to alkali showed lower germination percentage if bracteoles were removed from the fruit