Acta Univ Latv (2003) 662: 59–65

Possible role of trichomes in resistance of strawberry cultivars against spider mite

Abstract

The trichome types on leaves of garden strawberry (Fragaria × ananassa) were analyzed. Two types of trichomes was described. The fi rst were unicellular long and thin simple trichomes, located mainly on leaf veins and leaf margins, mostly on the underside of the leaf. The second were smaller multicellular uniseriate glandular trichomes. These trichomes consisted of one basal epidermis cell, several stalk cells, and a single rounded head cell. Strawberry cultivars with different resistance against two-spotted spider mite (Tetranychus urticae Koch) were used to test a hypothesis that higher pubescence in strawberry cultivars is correlated with a higher degree of resistance against the herbivore. Nonglandular trichomes were not the resistance factor for strawberry cultivars against spider mite because trichome density was affected by growth conditions and developmental state. It was concluded that gladular trichome-localized inducible responses are among the potential resistance mechanisms against spider mite in garden strawberry.