Seed coat and aging conditions affect germination and physiological changes of aging Korean pine seeds

ABSTRACTThe study was conducted to obtain information on possible seed aging during the long-term storage period of Korean pine seeds with thick impermeable seed coat. The seeds were artificially aged at 18, 24, 37 and 45°C for 35 days. Germinations percentages (GP) of aged seeds were highest on 25 days at 18°C, 15 days at 24°C and 10 days at 37°C. The seeds exposed at 45°C have completely lost their germinability after 5 days of aging. From 5 days of aging, mean germination times (MGT) were lower than control seed. The electrical conductivity on 10 days at 45°C reached 1.5–2.5 times its control seed, and had a positive correlation with the GP and a negative correlation with the MGT. The K+ was the most in leaching solution, and K+ and Mg2+ showed a high negative correlation between GP and MGT. The ratio of K+/Na+ had a higher correlation with seed vigor. The malondialdehyde (MDA) increased to 21 times of control seeds at 45°C after 35 days of aging, and had a negative correlation with GP and MGT. The ant...