Morphological characteristics and photosynthetic capacity of Fragaria vesca L. winter and summer leaves

The perennial herbaceous plant Fragaria vesca produces summer leaves that are shed in autumn and new overwintering leaves in autumn. The aim of this study was to identify the morphological and physiological differences between the two sets of leaves to examine the adaptation of this species to a cold seasonal climate. The winter and summer leaves of F. vesca are dimorphic in their morphological and anatomical features. Compared with the summer leaves, the winter leaves are smaller and have abundant hairs, their stomatal density is higher and their mesophyll is denser with more palisade parenchyma cells. Many of these features can be regarded as adaptations to light intensities, freezing temperatures and frost desiccation stress in winter. The winter leaves also maintain high photosynthetic capacity throughout the winter, thus extending the photosynthetically active season of the species. The dimorphic leaves of F. vesca, with their distinct structural features, allow the plant to maintain its metabolic activity in a northern seasonal climate, where the growing season is relatively short and environmental conditions that are not optimal for metabolic activity prevail a major part of the year.