srjalsSRJALSSRJALS2788-9386https://doi.org/10.47310/srjals.2023.v03i02.021Effect of some heat stress protectants on vegetative, floral, and anatomical traits of shrub rose plantWasanFawzi FadelAl-IbrasimAbdui-KadumN.S.Al-ShowilyMohammedAbdulameer HasanAlnajjarThe study was carried out under the fabric shade of the Medicinal and Aromatic Plants Unit, which is part of the College of Agriculture at the University of Basrah, on the one-year-old shrub rose plant Rosa hybrida L. Sultani variety. The plants were exposed to low temperatures in winter and high temperatures in summer. Two variables were included in the study: the first was heat stress (summer temperature at an average of 49°C and winter temperature at an average of 20°C) and the second one was treatment with amino acid glutathione at 0, 150 and 250 mg L⁻1. The study's results showed effect heat stress and stress protectants on the number of lateral branches in the shrub rose plant. The highest rate was recorded in the winter growth season, reaching 8.83 lateral branches, while the lowest rate was recorded in the summer, reaching 6.53 lateral branches. The treatment with glutathione also significantly affected the number of lateral branches in the plant. A concentration of 250 mg L⁻1 had the best results, with a maximum of 9.72 lateral branches, compared to the other treatments. There were 5.2 lateral branches at their lowest in the control group. The interaction between the winter growth season. Additionally, the treatment with 250 mg L⁻1 of glutathione resulted in the highest rates of plant height and flower number, reaching 86.34 cm and 11.19 flowers, respectively. The lowest rates were observed when the summer growth season was combined with a glutathione concentration of 0 mg L⁻1, reaching 59.65 cm and 6.66 flowers, respectively. Heat stress and stress protectants also affected anatomical leaves of shrub rose plant. The highest rate of cuticle layer thickness and tannin layer thickness was recorded in the summer growth season, reaching 20.75 and 35.96 µm, respectively, while lowest rates were recorded in winter growth season, reaching 15.51 and 28.27 µm, respectively. The treatment with glutathione also significantly affected the rate of cuticle layer thickness and tannin layer thickness. The treatment at 0 mg L⁻1 significantly outperformed the other treatments and recorded highest value of 22.39 and 40.29 µm, respectively. In comparison, the treatment at a concentration of 250 mg L⁻1 recorded the lowest value of 14.2 and 25.23 µm, respectively.