Seed germination characteristics of the desert subshrub Atriplex cana and its ecological significance

Atriplex cana is a xerophytic subshrub with drought resistance,salinity resistance and low fertility tolerance.It is a useful forage plant in Xinjiang. Experiments were conducted to determine the effects of temperature,seed bract removal,and Na Cl on seed germination. Seeds were able to germinate in a range of temperatures from 5 /15℃ to 25 /35℃. The higher the temperature,the faster the germination occurred. The optimum temperature regime for seed germination was 20 /30℃ and 25 /35℃. Under a 25℃ dark /35℃ light regime,the final germination percentage reached a maximum value after 6- 8 days of hydration,while under 5 /15℃ and 10 /20℃ temperature regimes final germination percentage was achieved after 25- 34 days. There was a significant increase in seed germination rate after 2- 8 months seed storage,while germination percentage of seeds decreased when exposed to natural atmospheric conditions for 10 months. Bracts formed a mechanical barrier to water uptake,and has a significant influence on the final seed germination rate. Removal of bracts promoted seed germination. Germination was not affected by Na Cl at concentrations below0. 8 mol / L,but was decreased by Na Cl at higher concentrations. Seeds incubated in Na Cl at concentrations of 0. 05- 4.00 mol / L recovered after being transferred to distilled water. After Na Cl treatment some seeds retained their vigor,while others lost vigor. Research into seed germination characteristics may reveal a scientific basis for this ecological adaptation trait. Such research may also provide basic data for improvement salinity tolerant forage subshrub production in the Xinjiang desert.