短时高温处理对云南松种子萌发的影响

Effect of Short-Term Heating Pretreatment on Germination of Pinus yunnanensis Seeds

为探究中低强度火灾后云南松种子的可能萌发情况和火对种子的影响,在萌发前对其种子进行1、5 min与15 min的60、90℃与110℃高温处理,以常温(20℃左右)为对照,研究种子萌发率、种子抗氧化酶超氧化物歧化酶(SOD)、过氧化酶(POD)和过氧化氢酶(CAT)活性的变化,以及萌发率与SOD、POD、CAT活性的关系。结果表明:60℃的1、5min处理可以促进种子萌发,种子存在热冲击效应;且具有较强的耐高温性,在110℃、15 min的高温处理后仍有36%±3%的萌发率;种子萌发率与SOD、POD和CAT呈极显著正相关关系,热冲击效应的产生与SOD、POD、CAT活性密切相关。

In order to explore the possibility of Pinus yunnanensis seed germination after a middle and lower strength fire,and the effect of fire on seeds,the P.yunnanensis seeds were subjected to three heat treatments （60℃,90℃ and 1 10℃ separately）for 1 min,5 min and 15 min,together with a group of seeds treated under 20℃ as control.The differences in seed germination rate,the activities of anti-oxidant enzyme of superoxide dismutase （SOD）,peroxidease （POD）,catalase （CAT）of the seeds with different treatments were determined, and the correlations of the germination rate with SOD,POD,and CAT activities were studied.The results showed that 1 min and 5 min pretreatment of the seeds under 60℃could promote the germination rate,indicating that there was a thermal shock effect on the P.yunnanensis seeds.The germination rate still reached 36%±3% after the treatment at 1 10℃ high temperature for 15 min,showing that to some extent,P.yunnanensis seeds had a good resistance on high temperature.The results also showed that SOD,POD and CAT activities were extremely significantly and positively correlated with germination rate of P.yunnanensis seeds,the generation of thermal shock effect was closely related to SOD,POD,CAT activities.