Germination and storage behaviour of seeds of the subtropical evergreen tree Daphniphyllum glaucescens (Daphniphyllaceae)

Daphniphyllum glaucescens Blume ssp. oldhamii (Hemsl.) Huang is an important subtropical evergreen tree in Taiwan. Seeds of D. glaucescens have non-deep, simple, epicotyl morphophysiological dormancy, and a minimum of 10–12 weeks is required for the first step of seedling production, i.e. hypocotyl emergence. It is not knownhowto decrease the time for seedling production and how to store seeds for retention of viability. We determined the effects of (i) gibberellic acid and cold-stratification on germination (hypocotyl emergence) and (ii) storage temperature and seed moisture content (MC) on germinability. Exogenous application of GA3 and of GA4 promoted germination and increased the germination rate. Moist cold-stratification at 5C also promoted germination; the longer the stratification period, the faster the rate of germination. More than 70% of seeds (fresh seeds, MC= 37.6%) dried to an MC of 6.4%, 8.5% and 25.5% (fresh weight basis) retained germinability after a 1-month storage at 5C, whereas germination percentage decreased to 0–2% after a 12-month storage at the same temperature. Germination percentage of seeds dried to the same MC and stored at 15C decreased to 0% after 8 months, whereas seeds stored at 20C did not germinate even after just 1 month of storage. The present evidence suggests that seeds of D. glaucescens have intermediate rather than orthodox or recalcitrant storage behaviour.