Effect of cold stratification on the temperature range for germination of Pinus koraiensis

Abstract Germination at low spring temperatures may offer a competitive advantage for the growth and survival of plant species inhabiting temperate forest ecosystems. Pinus koraiensis is dominant in forests northeastern China. Its seeds exhibit primary morphophysiological dormancy following dispersal autumn, limiting natural or artificial regeneration: direct seeding planting seedlings spring. The aim this study was to determine optimum cold stratification temperature that induces germination increase towards lower temperatures. Seeds from two populations (Changbaishan Liangshui) were stratified 0, 5 10 °C. incubation (10/5, 20/10, 25/15 30/20 °C; 14/10 h day/night) determined after 2 4 weeks, 5.5 6.5 months stratification. After months, approximately 68–91% both germinated °C °C, regardless When reduced 0 period increased 10/5 significantly improved, reaching 37% 64% Changbaishan Liangshui populations, respectively. stratification, there significant linear regression between range allowing gradually expanded include with decreasing further