The relationship between the effects of drought stress on some physiological and biochemical properties and morphological characteristics of oriental spruce [Picea orientalis (L.) Link] seedlings

In this study, the biochemical and physiological responses of Oriental spruce seedlings, grown from seeds obtained from seed stands, to drought stress were investigated. The research focused on both the general response of the species to drought and the variations in how different populations react to this stress factor. Parameters such as pre-dawn plant water potential, soil temperature, and soil moisture were measured in Oriental spruce seedlings, along with the analysis of chlorophyll a, chlorophyll b, total chlorophyll, total carotenoid, and total soluble carbohydrate contents. Additionally, some morphological characteristics of four-year-old seedlings were evaluated, and the relationship between these traits and responses to drought stress was assessed. The results showed significant differences among the populations in terms of biochemical and physiological parameters, as well as morphological traits. As the drought stress duration increased, plant water potential, chlorophyll, total carotenoid, and soluble carbohydrate levels also increased in the stressed seedlings. Moreover, a strong correlation was found between the morphological variations and the biochemical and physiological responses of the seedlings to drought stress, with parameters such as root dry weight percentage, sturdiness index, and Dickson quality index highlighting these relationships.