【作者】 赵艳；

【导师】 云兴福；

【作者基本信息】 内蒙古农业大学 ， 蔬菜学， 2009， 硕士

【摘要】 本试验在对黄瓜植株子叶期(子叶充分展开)和真叶期(第1真叶横宽5cm)进行不同程度的机械损伤处理下,研究机械损伤对黄瓜植株生长的直观损伤效应和黄瓜叶片内的几种关键防御酶活性的变化,探索出黄瓜植株损伤后体内生理生化变化的应答机制,为机械伤害刺激信号转导作用的机理提供新的认识,为黄瓜病害机械损伤诱导抗性及黄瓜生长过程中的整枝,打杈等损伤处理提供重要的理论依据和实践价值。研究结果表明:1.子叶期机械损伤和真叶期机械损伤均对黄瓜植株的生长有抑制作用。子叶期机械损伤处理后第15d起黄瓜植株的最大叶叶面积和叶数与对照达到了显著、极显著差异,损伤后第20d起黄瓜植株的茎粗与对照达到了显著、极显著差异。真叶期机械损伤处理后第15d起黄瓜植株的株高、茎粗、最大叶叶面积和叶数与对照达到了显著、极显著差异。2.子叶期或真叶期机械损伤后,损伤叶内的几丁质酶、β-1,3-葡聚糖酶、苯丙氨酸解氨酶(PAL)和超氧化物歧化酶(SOD)活性均高于对照。子叶期机械损伤后,损伤叶内的羧甲基纤维素酶和β-葡萄糖苷酶活性均低于对照,各处理的防御酶活性在损伤后36h—168h内出现峰值。机械损伤第1真叶48h后,损伤叶内的羧甲基纤维素酶和β-葡萄糖苷酶活性均低于对照,各处理的防御酶活性在损伤后6h—144h内出现峰值。3.机械损伤黄瓜子叶或者第1真叶后,均能显著诱导上部叶片内各种防御酶的活性。几丁质酶、β-1,3-葡聚糖酶、苯丙氨酸解氨酶(PAL)和超氧化物歧化酶(SOD)的活性较对照有不同程度的提高。在第1真叶损伤后,羧甲基纤维素酶和β-葡萄糖苷酶活性较对照有不同程度的降低,子叶期损伤后,羧甲基纤维素酶和β-葡萄糖苷酶活性在第4,5真叶中显著低于对照。由此可见,机械损伤可以显著诱导黄瓜体内各种防御酶的活性,表明机械损伤可以有效的诱导黄瓜体内伤害防御反应的产生,并做出相应的损伤修复反应,因而使黄瓜植株产生较强的抗性。机械损伤后,上部叶片内也有防御酶的产生和积累,表明机械损伤可以诱导黄瓜体内的伤信号转导,激活受伤诱导基因的表达,从而使植株产生各种防御酶来抵御外来伤害。更多还原

【Abstract】 In this experiment, the cucumber seedling were induced by mechanical wounding with different degrees at stage of cotyledon and the first true leaf, studying the visual damage effects on cucumber plant growth and the change of several key defensive enzymes activities in cucumber leaves, exploring the response to physiological and biochemical mechanism after mechanical wounding. then, these can provide a new understanding to mechanical injury signal transduction mechanism and provide important theoretical basis and practical value to cucumber disease induced resistance with mechanical wounding and the injury treatment in cucumber growth process, such as training, branch injury. The results showed that:1. Mechanical wounding with different degrees in cotyledon period and leaf period can inhibit the cucumber plant growth. After mechanical wounding treatment 15d at stage of cotyledon, the largest leaf area and leaf number with the control were reached a significant, very significant differences, after 20d, the width of cucumber plant with the control were reached a significant, very significant differences. After mechanical wounding treatment 15d at stage of the first true leaf, the height、the width、the largest leaf area and leaf number with the control were reached a significant, very significant differences.2. After mechanical wounding at stage of cotyledon or the first true leaf, chitinase,β-1,3-glucanase, PAL and SOD activities were higher than control. Cx andβ-glucosidase activities were lower than control in injury leaves, and defensive enzymes activity of all treatments peak appears between 36h and 168h after mechanical wounding at stage of cotyledon. After mechanical wounding 48h at stage of the first true leaf, Cx andβ-glucosidase activities were lower than control in injury leaves, and defensive enzyme activity of all treatments peak appears between 6h and 144h after mechanical wounding.3. Mechanical wounding at stage of cotyledon or the first true leaf can induced all kinds of defensive enzyme activities significantly in upper leaves. The activities of chitinase,β-1,3-glucanase, PAL and SOD in cucumber leaves were higher than that of the control after mechanical wounding. Cx andβ-glucosidase activities were lower in different degree than that of the control after mechanical wounding at stage of the first true leaf, and the activities of Cx andβ-glucosidase significantly lower than that of control in section 4,5 Leaf after mechanical wounding at stage of the cotyledon.It is concluded that mechanical wounding can lead to enzyme activities in the cucumber leaves significantly. Shows that mechanical wounding can effectively induce plant defense response, and make the appropriate response to repair damage, so that the induced resistance was produced strongly throughout the cucumber plants. After mechanical wounding, the production and accumulation of enzyme activity were also observed in the upper leaves , thus, the wounding signal transduction can be induced and the expression of injury induced gene can be activate by mechanical wounding in cucumber plant, so that defense enzymes can be produced in cucumber plant to resist external injury.更多还原