Thyme Species Responses to Abiotic Stress

The aim of these studies was to assess the responses of 6 thyme species (Thymus kotschyanus, T.fedtschenkoi, T. daenensis, T. pubescence, T. sepyllum and T. vulgaris) to drought and freezing stress.Freezing tolerance of species assessed under both outdoor and laboratory conditions and survival rate,leaf free proline content, electrolyte leakage and super oxide dismutase, peroxidase and ascorbateperoxidase enzyme activity were measured. Drought tolerance of the species was assessed in a split-plotdesign with three irrigation intervals (8, 16 and 24 days) as main plot and six species (as sub-plot) withfour replications and morphological (shoot fresh weight and root/shoot ratio) and biochemical (prolineand enzyme activity) and physiological (electrolyte leakage) responses of the species evaluated underfield condition. Overall, all studied species showed a higher freezing and drought stress tolerance.However when they were compared to each other, T. kotschyanus, T. sepyllum, and T. vulgaris showedbetter performance under freezing stress conditions while, T. kotschyanus, T. sepyllum, and T. daenensisshowed higher drought tolerance in comparison to other species.

کلیدواژه ها:

Drought stress ، Freezing stress ، Native plants ، Survival rate