Dormancy induction in Leucanthemum vulgare is mediated by osmopriming treatment

Leucanthemum vulgare is a weed species used for ornamental purposes and it is common in native meadows, in open and thick woodlands and roadsides [1]. L. vulgare seeds do not show any dormant behaviour and their germination temperature optimum range is between 15 and 20° C [2]. In this study, we observed a remarkable drop in germination rate (-83%) when seeds were incubated for one-week with an osmoticum media (PEG 8000) (Fig. 1A). Interestingly, extending the osmopriming treatment period up to 9 weeks produced a reversion in germination response and treated seeds behaved as control experiment (Fig. 1A). One-week osmoprimed seeds sowed with 50 ?M of fluridone showed a significant germination increase (about 40%) significantly (P<0.001) higher than osmoprimed seeds imbibed without hormone (Fig. 1B). Fluridone inhibits the carotenoid pathway depleting the ABA biosynthesis [3], which presence is associated with the mantainance of physiological dormancy [4]. Molecular analyses are currently being carried out to isolate dormancy related genes DOG1 (Delay Of Germination 1), FLC (Flowering Locus C), and HUB2 (Histone Mono-Ubiquitination 2) in this species and to analyse their expression profile during dormancy induction and its release (Fig. 3). These new findings can better elucidate the molecular mechanisms involved in seed dormancy onset and its regulation.