Seed Science Society of Iran Iranian Journal of Seed Science and Technology 2322-2646 8 1 2019 06 22 Effect of cooling pre-treatment on germination criteria and drought stress resistance in Dorema ammoniacum Effect of cooling pre-treatment on germination criteria and drought stress resistance in Dorema ammoniacum 241 251 119619 10.22034/ijsst.2018.116869.1155 FA Hamidreza Naseri Department of Desert Management, International Desert Research Center, University of Tehran Seyed Alireza Hosseini Department of Range and Watershed Management, Faculty of Natural Resources, University of Hormozgan Nateq Lashkari Sanami Department of Range Management, Faculty of Natural Resources, Sari Agricultural Sciences and Natural Resources University Journal Article 2017 12 26 Water deficiency is one of the important problems in arid and semi-arid regions. Thus, in germination and growing stages selection of resistant medicinal plant species is very important. In this investigation in order to seed dormancy breakage of Dorema ammoniacum seeds, wet cooling treatment was assessed first. After selection of the best cooling treatment (5 °C), treated seeds were placed in germinating medium with drought stress; at a period of 20 days at 15 and 20 °C. Drought stress trial was conducted at 5 levels as factorial layout based on a completely randomized design including control, -4, -8, -12, and -16 bar treatments. PEG was used to make drought stress. Results showed germination rate and percentage, radicle length, and stem length were significantly (p < 0/01) decreased by increasing drought stress. The best range for germination in conditions of without stress was to -12 bar water potential. It appears that stem length was more vulnerable than other characters. In addition, 20 °C was the most appropriate temperature for germination under drought treatment. Water deficiency is one of the important problems in arid and semi-arid regions. Thus, in germination and growing stages selection of resistant medicinal plant species is very important. In this investigation in order to seed dormancy breakage of Dorema ammoniacum seeds, wet cooling treatment was assessed first. After selection of the best cooling treatment (5 °C), treated seeds were placed in germinating medium with drought stress; at a period of 20 days at 15 and 20 °C. Drought stress trial was conducted at 5 levels as factorial layout based on a completely randomized design including control, -4, -8, -12, and -16 bar treatments. PEG was used to make drought stress. Results showed germination rate and percentage, radicle length, and stem length were significantly (p < 0/01) decreased by increasing drought stress. The best range for germination in conditions of without stress was to -12 bar water potential. It appears that stem length was more vulnerable than other characters. In addition, 20 °C was the most appropriate temperature for germination under drought treatment. https://ijsst.areeo.ac.ir/article_119619_0b5e9889b9e489421726c68f8dd5fc02.pdf