Terminal Flower 1 Gene is a Breeding Target for a Novel Everbearing Trait in Octoploid Strawberry

The effects of daylength and temperature on flowering of the cultivated octoploid strawberry (Fragaria × ananassa Duch.) have been studied extensively at the physiological level. However, information on the molecular pathways controlling flowering in the species is scarce. The team of Elli Aurora Koskela of the University of Helsinki in Finland now aims to shed light on that particular pathway.

The flowering pathway has been previously studied in the diploid short-day woodland strawberry (F. vesca L.). There, the FLOWERING LOCUS T1 (FvFT1), SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (FvSOC1), and TERMINAL FLOWER1 (FvTFL1) genes were found essential for the correct timing of flowering.

In Koskela's work, they showed that silencing the floral repressor FaTFL1 in the octoploid short-day strawberry cultivar ‘Elsanta' is sufficient to induce perpetual flowering under long days without direct changes in vegetative reproduction. The team also found that the genes FaFT1 and FaSOC1 show similar expression in different cultivars and that the regulation of FaTFL1 varies widely from cultivar to cultivar and is correlated with floral induction. This indicates that transcription of FaTFL1 occurs independently from the FaFT1–FaSOC1 module.

The results indicate that changing the expression of FaTFL1 could result in strawberries with specific flowering and runnering characteristics, including new types of everbearing cultivars.

Read more about the study on Plant Biotechnology Journal.