عنوان مقاله [English]
Due to the climate change and the ecological value of the purple species, knowledge of resistance of this species to different levels of drought stress is essential. In order to investigate the effect of drought stress on morphophysiological and biochemical traits of purple seedlings, an experiment in a completely randomized design with four levels of drought stress including field capacity 100% , 75% , 50% and 25% was performed in greenhouse conditions. The results showed that drought stress reduced morphological traits such as height growth of seedlings, leaf number growth and total wet and dry biomass, but increased root volumetric growth. The results displayed that drought stress strongly affected all parameters of gas exchanges and photosynthetic pigments. Drought stress of 25% of field capacity caused reduction in photosynthesis rate, transpiration, stomatal conductance and mesophilia, intracellular carbon dioxide concentration and carboxylation efficiency. The amount of photosynthetic pigments also showed decrease at 25% of field capacity the maximum values of the mentioned parameters were obtained at mild stress of 75% of the field capacity. The results showed drought stress increased the amount of proline and soluble sugar and showed the highest values at the level of 25% of field capacity. according to the evaluation of morphophysiological and biochemical traits of purple species, it can be said that this species has withstood water stress up to 75% of field capacity without causing damage, and if the of water is reduced to the threshold of 25% of field capacity, its growth will be affected.