اﺛﺮ زﻣﺎﻧﻬﺎی ﻣﺨﺘﻠﻒ ﻛﺎرﺑﺮد آب داغ ﺑﺮ ﺷﻜﺴﺖ ﺧﻮاب ﺑﺬر ﺧﺘﻤﻲ(Althaea officinalis)

To find the optimal duration of treatment with hot water (85°C) to break seed dormancy of Althaea officinalis, this study was conducted in Physiology Laboratory of Faculty of Science in Islamic Azad University of Mashhad (2013-2014). Scarification with hot water (ranged from 1 to 7 minutes) was performed on the bases of completely randomized design with four replications in a factorial arrangement. First factor was the seed coat (removed or not) and the second factor was the duration of hot water treatment. Studied traits were germination percentage, speed of germination, root length, shoot length, seed vigor and mean daily germination. The results showed the main effect of coat in all traits was significant. Removing seed coat increased the germination traits. The effect of time of treatment with hot water was also significant in all traits. Seed treatment with hot water for four minutes, increased the percentage of seed germination compared to the control. Root and shoot length, seed vigor and mean daily germination of seed treated for four minutes caused a significant increase in these traits. Seed treatments with hot water in longer times caused a tangible decrease in of these traits led to damping off the Althaea officinalis seeds. In all of these traits, the reaction of the seeds without coat was better than the seeds with coat, at the same time. In conclusion seed treatments with hot water for four minutes showed significant effect to break dormancy of Althaea officinalis seeds and treating seed for longer times led to damping off of the seeds.