Evaluation of seed germination characteristics in Nepeta binaludensis, a highly endangered medicinal plant of Iran

To study the germination characteristics and cardinal temperatures of Nepeta binaludensis a laboratory experiment was conducted. In this experiment the effects of seven constant temperatures including 5, 10, 15, 20, 25, 30 and 35°C and three alternate temperatures including 5/10, 10/20 and 20/30°C on germination percentage and germination rate was studied. The highest germination percentage was obtained at temperatures between 20-30 °C while the highest germination rate was recorded at 20 °C. Alternate temperatures have also a significant effect on germination characteristics of this species. The highest germination percentage and germination rate were recorded in alternate temperature of 20/30 °C. Base, optimum and critical temperatures were 7.4-9.9, 22.9-23.7 and 35.7-37.1°C, respectively.