论文部分内容阅读
以津春四号黄瓜(Cucumis sativusL.‘Jinchun 4’)为实验材料,通过同时测定黄瓜叶片叶绿素荧光快速诱导动力学曲线和对820 nm光的吸收曲线,以及过氧化氢含量和过氧化氢酶(CAT)活性的变化,研究了核盘菌(Sclerotinia sclerotio-rum(Lib.)de Bary)侵染黄瓜叶片后,对光系统Ⅰ(PSⅠ)和光系统Ⅱ(PSⅡ)功能的影响,并分析了核盘菌侵染后,两个光系统之间的相互影响。结果表明,核盘菌侵染叶片后,叶片过氧化氢(H2O2)含量升高,膜脂过氧化的程度加剧,叶片放氧能力下降,快速叶绿素荧光诱导动力学曲线发生变化。核盘菌侵染严重伤害了PSⅡ供体侧(放氧复合体)、受体侧以及反应中心的活性,并且降低PSⅠ最大氧化还原能力(△I/Io)。核盘菌侵染黄瓜后,抑制了CAT的活性,导致过量活性氧的积累,直接伤害了光合机构PSⅠ和PSⅡ的功能;对PSⅠ的伤害抑制了PSⅡ电子向PSⅠ的传递,进一步加剧了PSⅡ的伤害程度,导致更多过剩激发能产生,造成恶性循环,这是核盘菌抑制黄瓜光合作用的主要原因。
Cucumber (Cucumis sativus L.’Jinchun 4 ’) was used as experimental material to measure the kinetic curve of chlorophyll fluorescence and the absorption curve of 820 nm at the same time, as well as the content of hydrogen peroxide and catalase (CAT), the effects of sclerotinia sclerotio-rum (Lib.) De Bary on the function of photosystem I (PSⅠ) and photosystem Ⅱ (PSⅡ) were studied. After S. sclerotiorin infection, the interaction between the two light systems. The results showed that the content of hydrogen peroxide (H2O2) increased, the degree of membrane lipid peroxidation increased, the oxygen releasing capacity decreased and the fast chlorophyll fluorescence induced kinetic curve changed after infected with S. sclerotiorum. S. sclerotiorum infection severely harmed the activity of PSⅡ donor side (oxygen-evolving complex), receptor side and reaction center, and decreased the maximum redox capacity of PSⅠ (△ I / Io). Sclerotinia sclerotiorum inoculation cucumber, inhibit the activity of CAT, leading to the accumulation of excess reactive oxygen species, directly damage the function of photosynthetic institutions PS Ⅰ and PS Ⅱ; injury to PS Ⅰ inhibit the transfer of PS Ⅱ electrons to PS Ⅰ, further exacerbating the PS Ⅱ Injury, leading to more excess excitation can produce, resulting in a vicious cycle, which is Sclerotinia cucumber inhibition of photosynthesis is the main reason.