Influence of Stratification on Seed Germination of Pterocarya fraxinifolia (Poiret) Spach, a Relic Tree Species

摘要

In the present study, the effect of stratification on the germination of Pterocarya fraxinifolia seed was studied. Collected seeds were cold stratified without a medium at moist low temperature for 0, 3, 5 and 7 weeks at a constant temperature of 4±PC or warm stratified for 3 weeks at 20 deg C for 8 h and 4 deg C for 16 h (20/4 deg C). After each stratification duration, the seeds were placed in a germination chamber at a temperature regime of 8 h at 30 deg C plus 16 h at 20 deg C (30/20) in darkness and Germination Percentages (GP) and germination rates (PV) were determined. 3, 5 or 7 weeks of cold stratification without a medium broke the seed dormancy and produced more than 90% germination. Germination rate was the highest after 5 or 7 weeks ofcold stratification. The present study reveals that Pterocarya fraxinifolia has seed dormancy and 5 weeks of cold stratification without a medium is necessary to maximize seed germination percentage and germination rate.