Effects of water stress on seed germination of Thymus kotesschanus Boiss. and Thymus daenensis Celak

Study on growth status of medicinal plants in different water stress conditions can be considered as the cultivation guide for resistant plant species. The current study was carried out to investigate the effects of water stress on seed germination of Thymus koteschanus and Thymus daenensis. To achieve this goal, polyethylene glycol (PEG) was used to provide appropriate water potentials (0, -0.3, -0.6, -0.9, -0.12, -0.15 and -0.18 MPa). A completely randomized design was applied as the experimental design with three replications and all data were analyzed using SAS software.Mean comparisons was done through LSD test. The results showed significant differences between two studied thymes and maximum germination velocity and vigor index were recorded for Th. koteschanus. There were also significant differences among all studied traits in different treatments as they were decreased with increase of water stress and no germination was recorded under sever water stress. According to the results, it could be concluded that the effcts of water stress on germination of Thyme was negative and caused a reduction in germination parameters.

Water stress Thyme Thymus koteschanus Thymus daenensis Germination