Variability of the Photosynthetic Pigment Complex in Spruce Trees with Different Seed Scale Shapes in the Northern Taiga of the Arkhangelsk Region

<jats:p>Terrain of the Arkhangelsk region is part of the introgressive hybridization zone of Siberian spruce (Picea obovata Ledeb.) and European spruce (Picea abies (L.) Karst.) on the East European Plain. In many species of the Pinaceae family, the shape of the seed scales contains a wealth of genetic information specific to both the species and its varieties. The research aimed at determining the seasonal dynamics of the photosynthetic pigment complex in Siberian spruce and hybrid spruce with a predominance of Siberian spruce traits in the northern taiga of the Arkhangelsk Region. The field studies were carried out in blueberry spruce forests on low-podzolic loamy soils overlying morainic loams, typical in the northern taiga near the mouth of the Northern Dvina River (64°30ʹ N, 41°00ʹ E). We have labelled 10 Siberian spruce trees and 10 hybrid spruce trees with a predominance of Siberian spruce traits, determined by the seed scale shape at the permanent trial plots. Samples of annual (shadow) needles were harvested from the lower part of the crown at various times of the year in 2023. Spectroscopic methods allowed us to determine the chlorophyll and carotenoid content in pine needles and to calculate the proportion of chlorophylls in the light-harvesting complex. The results revealed similarities in the dynamics of relative parameters of the photosynthetic pigment complex in annual needles of Siberian spruce and hybrid spruce with a predominance of Siberian spruce traits. Meanwhile, the research shows that during the summer and fall seasons, right up until the end of the growing season and as they prepare for winter dormancy, the spruce trees studied accumulate green pigments, with the hybrid form exhibiting this process more actively. This increases the protective role of carotenoids. The range of variation in the proportion of chlorophylls in the light-harvesting complex of Siberian spruce and hybrid spruce with a predominance of Siberian spruce traits from May to November averages 55–62 % per month, which is due to the adaptation of their photosynthetic apparatus to the ecological conditions of high latitudes.</jats:p>