聚乙二醇渗透处理对水曲柳种子在不同温度下萌发的影响

Germination Response of Fraxinus mandshurica Seed to Polyethylene Glycol Osmotic Treatment under Different Temperatures

为探究聚乙二醇(PEG)渗透处理对水曲柳种子次生休眠诱导的影响,以解除初生休眠的水曲柳种子为材料,研究经不同质量分数(0,5%,25%,50%)PEG渗透处理不同时间(3,7,14d)后种子在不同温度(15和25℃)下的萌发表现。结果表明:在适宜萌发温度(15℃)下,PEG渗透处理不会诱导种子进入低水势引起的次生休眠。但不同渗透处理对种子发芽的影响不同:低质量分数(5%)渗透处理和中等质量分数(25%)的短时间(3d)渗透处理对种子萌发有明显的促进作用,但中等质量质量分数的中等(7d)和长时间(14d)渗透处理以及高质量分数(50%)的渗透处理都对种子萌发不利。在高温(25℃)下,中高质量分数PEG短时间渗透处理或高质量分数PEG中长时间渗透处理对种子热休眠诱导有明显的减弱作用,但低质量分数PEG渗透处理没有减弱热休眠的效应。

In order to investigate the effect of polyethylene glycol (PEG) osmotic treatment on secondary dormancy induction of Manchurian ash ( Fraxinus mandshurica ) seed,the primary dormancy released seeds were used to study the germination performance of seeds at different temperatures (15 ℃ and 25 ℃) after PEG treatment in different concentrations (0%,5%,25%,and 50%) for different time (3,7,and 14 d).The PEG treatment did not induce secondary dormancy caused by low water potential at suitable germination temperature (15 ℃).However,different osmotic treatments have different effects on seed germination: low concentration (5%) treatment and medium concentration (25%) short-time (3d) treatment have a significant effect on seed germination,but medium concentration moderate (7d) and long-term (14d) treatment,and high concentration (50%) treatment are detrimental to seed germination.Under high temperature (25 ℃),the medium to high concentration PEG short-time treatment and moderate to long-term treatment in high concentration significantly circumvent the thermodormancy induction,but the low concentration PEG treatment do not have the effect of circumventing thermodormancy.