Seed soluble sugar concentrations
Soluble sugars were extracted from three replicates of 18 mg from lyophilized and ground seeds (pooled from the four plants), with 1 mL methanol/water (80:20, v/v) and 40 µL melicitose used as the internal sugar standard. Glucose, fructose, sucrose, raffinose, and stachyose contents were quantified using HPLC (DIONEX ICS-3000) according to Brunel-Muguet et al. (2015). The [raffinose+stachyose]:sucrose ratio was used as an indicator of seed drying tolerance i.e. the higher the value, the more tolerant the seed is to desiccation (Bailly et al. 2001).