determination of seed dormancy type in bileher (dorema aucheri)

Introduction: dorema aucheri, a species from the apiaceae family, is recognized as a valuable and multipurpose plant in the rangelands and mountainous regions of western iran. however, due to overharvesting, this plant is currently endangered. since the propagation of this plant in its natural habitats occurs through seeds and considering that its seeds exhibit deep dormancy, understanding the type of seed dormancy is essential for achieving uniform germination and for the conservation of this species. materials and methods: to determine the type of dormancy in dorema aucheri, an experiment was conducted in a factorial arrangement based on a completely randomized design with three replications at the faculty of agricultural technology, aburaihan campus, university of tehran, in the fall of 2023. the first factor was stratification temperature (5, 10, 15, 20, and 25°c), the second factor was stratification duration (8 weeks), and the third factor was gibberellic acid concentration (0 and 100 ppm). in this experiment, traits such as germination percentage, germination rate, and seedling length were measured. results and discussion: the results indicated that the main effects of temperature (t), stratification duration (w), gibberellic acid (ga), as well as the interactions between temperature and stratification duration, and temperature and gibberellic acid, had significant effects on germination percentage and germination rate. the highest germination percentage, germination rate, and seedling length were observed at 5°c. additionally, gibberellic acid treatment significantly increased the germination percentage of dorema aucheri seeds. conclusion: it can be concluded that the dormancy of dorema aucheri is a complex, shallow morphophysiological dormancy. the combined use of cold stratification at 5°c for eight weeks and 100 ppm gibberellic acid was effective in breaking the dormancy of dorema aucheri seeds.