论文部分内容阅读
Global temperatures are rising gradually.In a future warmer Northern Hemisphere, the increase of soil temperature during summer is likely to impact seed germination behavior.Seed germination behavior of Pinus koraiensis in response to simulated temperature rise was investigated.How warmer June temperature (+4 ℃、 +6 ℃) influenced Pinus koraiensis seed germination behavior was tested in three growth chambers.A 4 ℃ or 6 ℃ temperature increase in June significantly increased final germination percentage and germination rate index (GRI), but decreased the time necessary to reach 50% of the final germination percentage (T50) as well as mean germination time, in addition, the initial period of downward seedling growth following germination was also inhibited.The activity of Catalase (CAT) on the 9th day and glutathione reduCtase (GR) on the 25th day after seeding significantly increased when temperatures increased by 4 ℃ or 6 ℃, but ascorbate peroxidase (APX) showed no pronounced change.A 4 ℃ or 6 ℃ warming may improve Pinus koraiensis seed germination behavior, if moisture is not limited,and the most suitable temperature was found at +4 ℃.The improvement of the germination behavior could be attributed to increased CAT and GR activities, however, APX show little help.The germination rate is more sensitive to elevated temperature than final germination percentage and physiological parameters prior to morphology indexes.Our results implied that the global warming could accelerate Korean pine seed germination rate, thus influence the soil seed bank of Korean pine.