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期 刊 ：植物保护学报 2011年

关键词：苹果；

Keywords:Alternaria augustiovoide, Echinochloa crus-galli, tenuazonic acid, lipoxygenases, lipid peroxidation,

摘 要 ：陕西渭北的黄土高原是我国苹果的主要产区,该地区果园地形复杂,地面植被丰富,生产上往往需要投入大量的人力和物力清除杂草。果园植物的种类对果园昆虫多样性有明显影响,果园生物多样性指数维持较高水平时害虫不易成灾。严毓骅和段建军及王大平研究表明,在苹果园保留夏至草,或间作苜蓿、三叶草、白花草木犀、百脉根等可提高天敌昆虫的多样性,有助于发挥天敌昆虫的作用。果园地面杂草覆盖度较高时,捕食性蜘蛛的丰富度和多样性也较高,可有效控制果园中的主要害虫。目前,关于黄土高原苹果园杂草多样性以及不同杂草对天敌昆虫的影响尚未见报道。本试验对陕西省黄陵县不同地形的苹果园地面植被进行系统调查,明确杂草种类及优势种,并对杂草群落与果园天敌昆虫群落相似性进行了比较。

Abstract:In order to know the action of tenuazonic acid (TeA) produced by Alternaria augustiovoide strain AAEC05-3 on Echinochloa crus-galli (L.), the effect of TeA on lipid peroxidation of E.crus-galli leaf was studied by leaf segment method in vitro. The result showed that low concentration TeA did not affect the membrane permeability and lipid peroxidation of E.crus-galli leaf, but the membrane permeability and lipid peroxidation increased significantly in 24 h after treatment with high concentration of TeA. When E.crus-galli leaves were treated with 100μmol/L TeA, the relative conductivity and malondialdehyde (MDA) content increased 28.21% and 63.58%, respectively. After the treatment of 100μmol/L TeA, lipoxygenases (Lox) activity of leaf increased 61.59%, meanwhile, the content of unsaturated fatty acids decreased dramatically. The content of linoleic acid and linolenic acid decrease 19.56% and 17.20% in 100μmol/L TeA treatment, respectively. After the treatment of 100μmol/L TeA, the fatty acid hydroperoxides (FAH) was largely accumulated in E.crus-galli leaf. The results indicated that TeA could induce the lipid peroxidation of E.crus-galli leave. It is deduced that the lipid peroxidation induced by TeA could be Lox-mediated lipid peroxidation.

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