The Influence of Drought Stress on Seedlings of Four Deciduous Species, Common in Nurseries of the Semi-Arid Region of Iran

Aim: With global warming and limited water resources in the world, especially in the arid lands of Iran, managing the production of forest seedlings in the country’s nurseries is facing a particular challenge. In this regard, the study of drought-tolerant plants to select them in the mass seedling production programs can be helpful. Material and methods: Potted seedlings of Persian oak (Quercus brantii), pistachio (Pistacia atlantica), common purple (Cercis siliquastrum), and black poplar (Populus nigra) under regular irrigation (100% field capacity) and drought-stressed (30% field capacity) conditions were examined over 120 days in the greenhouse of Bam Khorramabad Nursery. Findings: In all species in stressed seedlings compared to control seedlings, the content of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids decreased, but the content of proline and malondialdehyde (MDA) increased. Under stress conditions, MDA content in black poplar, common purple, Persian oak, and pistachio was 174, 121, 105 ,and 102% higher than under control seedlings, respectively, and this increase in black poplar over other species ranged from 93.5 to 176.5%. Conclusion: This study confirms that black poplar has a lower resistance rate to drought stress among four tree species. Thus, due to their higher tolerance to water scarcity, Persian oak, pistachio, and common purple can be prioritized in the mass seedling production programs of nurseries in arid areas suffering from limited water resources.