A Review of Photoperiodic Flowering Research in Strawberry (Fragaria spp.)

Throughout the last century many researchers have examined the physiology and molecular events surrounding an important milestone in plant development—the transition to flowering. Breakthroughs over the last decade have brought great molecular resolution to the process, allowing researchers to peer into the former black box that once obfuscated the mechanisms governing this evolutionarily and agriculturally important transition. Foundational studies in the physiology of flowering regulation have been performed in many species, but the greatest mechanistic clarity has come from studies in Arabidopsis thaliana. At the same time parallel efforts by researchers, nurserymen and farmers queried the wide variation in strawberry (Fragaria spp) flowering habits. The complex ranging flowering behaviors driven by the cumbersome genetics of the cultivated octoploid strawberry have slowed the understanding in this crop, yet a remarkable literature exists that documents examination of flowering in the genus. Strawberry is a high-value crop and a comprehensive understanding of flowering behaviors is required to optimize production and streamline breeding efforts. Studies in strawberry may offer new insights into quantitative mechanisms that shape the floral transition, and new mechanisms may be identified. Moreover, strawberry is a member of the Rosaceae, a family containing valuable fruit, nut and ornamental crops. Findings in strawberry will likely translate well to other crops in the family. This review compiles a century of observations and experimental results, and looks forward to the unique opportunities that may arise from contemporary studies of flowering time in this genus.