Ecophysiology of seed germination in Dodartia orientalis L.
Dodartia orientalis is an invasive and perennial weed of the Scrophulariaceae family. Comprehensive research in association with the biology and some environmental factors on sexual reproduction of this weed has not done yet. in order to study of some factors affecting on seed germination of this weed, an experiment took place in Weed Research Department of Iranian Research Institute of Plant Protection that included effect of temperature, light, scarification with concentrated sulphuric acid, gibberelin, and salt stress (NaCl) on seed germination. Dodartia seed viability was 62.5%. Optimum constant temperature for seed germination was 22°C, and optimum alternate temperature was 25/15°C. Alternating temperatures compared to constant temperatures was more appropriate for seed germination of Dodartia. The seed did not need to light for germination. Chemical stimulation of seed with concentrated sulfuric acid (98%) for 2 min was the best stimulus for breaking dormancy of this weed. Gibberelin was not able to stimulate Dodartia seed germination. The seeds germinated at the concentrations of NaCl lower than 200 Mm.