TERMINAL FLOWER1 is a breeding target for a noveleverbearing trait and tailored flowering responses incultivated strawberry (Fragaria × ananassa Duch.)

摘要

The effects of daylength and temperature on flowering of the cultivated octoploid strawberry(Fragaria × ananassa Duch.) have been studied extensively at the physiological level, butinformation on the molecular pathways controlling flowering in the species is scarce. Theflowering pathway has been studied at the molecular level in the diploid short-day woodlandstrawberry (F. vesca L.), in which the FLOWERING LOCUS T1 (FvFT1)–SUPPRESSOR OFOVEREXPRESSION OF CONSTANS1 (FvSOC1)–TERMINAL FLOWER1 (FvTFL1) pathway is essentialfor the correct timing of flowering. In this work, we show by transgenic approach that thesilencing of the floral repressor FaTFL1 in the octoploid short-day cultivar ‘Elsanta’ is sufficient toinduce perpetual flowering under long days without direct changes in vegetative reproduction.We also demonstrate that although the genes FaFT1 and FaSOC1 show similar expressionpatterns in different cultivars, the regulation of FaTFL1 varies widely from cultivar to cultivar andis correlated with floral induction, indicating that the transcription of FaTFL1 occurs at leastpartially independently of the FaFT1–FaSOC1 module. Our results indicate that changing theexpression patterns of FaTFL1 through biotechnological or conventional breeding approachescould result in strawberries with specific flowering and runnering characteristics including newtypes of everbearing cultivars.