摘要:
以6 年生白桦为研究对象,在相同的火烧强度和火烧时间下对白桦不同部位进行火烧处理(整株主干火烧和 枝下主干火烧)后叶片生理代谢的变化及火后恢复情况进行研究。结果表明:火烧处理后0 ~10 d 火烧处理均导致 白桦叶片膜脂过氧化,相对含水量、叶绿素含量和叶绿素荧光参数(Fv / Fo、F'v / F'm、qP、ETR)显著降低;叶片启动了 应激机制,抗氧化酶SOD 活性和POD 活性显著提高,渗透调节物质脯氨酸含量和可溶性糖含量显著提高,表现出 一定的抗火性。火烧处理后10 d 火烧产生的伤害开始恢复,膜脂过氧化产物丙二醛含量开始下降,叶片相对含水 量、叶绿素含量和叶绿素荧光参数(Fv / Fo、F'v / F'm、qP、ETR)开始上升,到火烧后30 d 升高到对照水平,表现出等量 补偿效应,丙二醛含量下降到对照水平。火烧后40 d 叶绿素含量、叶绿素荧光参数(Fv / Fo、F'v / F'm、qP、ETR)显著高 于对照,表现出超补偿效应,白桦通过提高叶片的光合作用能力弥补火烧造成的伤害;脯氨酸含量和SOD 活性仍显 著高于对照,这是恢复的一种滞后反应,对树木逆境下生长是有利的。
关键词:
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火烧
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白桦
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生理响应
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火后恢复
Abstract:
In this study,the changes of leaf physiological metabolism and the recovery of fire treatments were studied. Using 6-year-old saplings of Betula platyphylla as the test materials,different parts(all the trunk and under branches of trunk) were fired under same fire intensity and fire time. The results showed that the leaves produced by lipid peroxidation and the relative water content (RWC),chlorophyll content and chlorophyll fluorescence parameters(Fv / Fo,F'v / F'm,qP,ETR)significantly decreased in 0-10 days after fire treatment. The antioxidant enzyme SOD activity,POD activity,proline content and soluble sugar content significantly increased,which showed the fire resistance of B. platyphylla. After 10 days of fire treatment,the damage began to recover and the content of MDA began to decline,the RWC, chlorophyll content and chlorophyll fluorescence parameter(Fv / Fo,F'v / F'm,qP,ETR) began to rise and reached control levels after 30 days of fire treatment. These showed equal compensation effects,and the content of MDA decreased to control level. The chlorophyll content and chlorophyll fluorescence parameters(Fv / Fo,F'v / F'm,qP,ETR)were significantly higher than control after 40 days of fire treatment,which showed super compensation effects. Increased leaf photosynthetic capacity repaired the damage by fire of B. platyphylla. The proline content and SOD activity were significantly higher than control,which was a delayed reaction and was beneficial for the growth of trees under stress.
百度学术
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