【作者】 胡韵雪；

【导师】 周祖基； 陈益泰；

【作者基本信息】 四川农业大学 ， 森林保护学， 2009， 硕士

【摘要】 本文研究了弗吉尼亚栎(简称弗栎)引种后的虫害情况并对其害虫星天牛的防治提出建议,同时探讨了弗栎的耐盐机制。确定星天牛为严重危害栎树混交林的虫种之一,对四种栎树混交林中星天牛的危害习性进行了林间调查和室内选择性试验,初步探讨了四种栎树挥发物组成与害虫危害程度的关系;另外,采用Hoagland溶液砂培方法对弗栎在高盐浓度(150mmol/L)和低盐浓度(50mmol/L)胁迫下叶片生理指标的动态变化以及处理2个月后的部分形态学参数进行研究,探讨其耐盐机制,主要结论如下:1.通过在浙江省富阳市新登、三桥林场,杭州市长乐林场和上海市松江林场的调查发现弗栎易被作为星天牛的补充营养寄主;在富阳地区,星天牛成虫补充营养的八种寄主植物中,星天牛的喜好程度从大到小依次为河桦＞复叶槭＞银槭＞柳叶栎＞弗栎＞纳塔栎＞水栎＞洋白蜡;在室内将上述八种寄主树种枝条作为选择材料供试,测量比较星天牛对其的取食面积并用各种枝条对星天牛进行生测实验,发现星天牛对植物枝条的喜好程度与林间调查结果一致。进而提出降低星天牛危害弗栎的方法:在弗栎林中,适量的混栽河桦、复叶槭、银槭等树种,引诱星天牛取食,达到保护弗栎,降低星天牛对其为害的目的。2.利用固相微萃取方法分析了四种栎树枝条挥发物的化学成分及其相对含量,发现栎树枝条中烷烃类和酯类物质的总含量从多到少依次为柳叶栎、弗栎、水栎、纳塔栎;而醇类和醛类物质总含量从多到少依次为水栎、弗栎、柳叶栎、纳塔栎。综合各类物质的相对含量发现,易感星天牛栎树释放更多的烷类及酯类物质,而相对危害较小的栎树则释放较多的醇、醛类物质。3.在不同盐浓度胁迫2个月后,弗栎植株均能够正常生长。弗栎叶片脯氨酸对盐胁迫做出的适应性反应出现在胁迫处理21天以后,而且对高盐浓度也能适应;整个盐胁迫过程中弗栎叶片叶绿素含量在高盐胁迫下均高于对照组;弗栎叶片在低盐浓度处理35d内及高盐对理21d时MDA含量均低于对照组;对叶片抗氧化系统的测定结果表明弗栎在盐胁迫初期已经感受到盐胁迫并积极调动抗氧化系统以适应逆境,且在高盐胁迫下积极响应。盐胁迫2个月后发现弗栎根冠比随着盐浓度的增加而增大;Na~+、Cl~-在弗栎根系的含量高于地上部,K~+/Na~+从小到大的顺序为根、茎、叶。对根系形态学参数的研究发现,低盐胁迫显著促进弗栎根系发育。通过实验发现弗栎在沿海地区引种后,受到星天牛等害虫的危害,但是我们可以通过配制星天牛的嗜食树种从而降低其被害率;植物的挥发性物质与虫害程度之间存在着响应的关系,这对进一步研究林木与害虫的相互关系以寻求更好的防治虫害方法提供了理论支持。另外,弗栎作为盐碱地优势树种对盐胁迫具有极强的适应性,其响应机制主要是通过积累脯氨酸、根系吸收有害离子、扩大根系吸收面积、抗氧化系统积极响应等,以吸收更多的水和养分、维持地上部的正常生长及植株的正常生理代谢。更多还原

【Abstract】 We studied on the pest situation of Quercus virginiana after introduction and made sugguestions about the pest control of Anoplophora Chinensis. Moreover, we discussed on the salts resistance mechanism of Quercus virginiana. We confirmed that Anoplophora Chinensis is one of pest species which caused serious harm to oak mixed forest ,we also did forest survey and laboratory selective test on its damage habits in four types of oak mixed forest; we preliminary studied the relationship between the composition of four oak volatile and the degree of pest damage; Furthermore, a sand culture of Hoagland experiment was carried out to investigate Quercus virginiana under high (150 mmol/L NaCl) and low (50 mmol/L NaCl) salt stress about the changes including dynamic trend about physiological parameters of leaves and some morphological parameter after 2 months, we investigated its salts resistance mechanism and got following conclusions:1.We make the pest-insect survey in Zhejiang Fuyang Xindeng and Sanqiao, Changle, Shanghai Songjiang Forest Farm and found Anoplophora chinensis is one of the very serious pest in mixed forest of oak forests. In the Fuyang area, the preference of A. chinensis adults for 8 host plants in the phase of supplermentary feeding was observed both in field and in laboratory and used various branches to do bioassay experiments. Acceptabilty of A. chinensis adult were Quercus phellos L., Quercus virginiana, Quercus nuttallii Palmer, Quercus nigra L., Fraxinus pennsylvanica ranging from high to low. Therefore infer the approach to decrease Anoplophora chinensis damage to Quercus virginiana is adding proper amount bait-trees,like Betula nigra, Acer negundo, cer saccharinum in oak forests.2. We analyzed the relative content and chemical composition of four oak volatile by solid phase micro-extraction method, found that total amount of alkanes and ester matter in oak branches was quercus phellos, Anoplophora Chinensis, water oak , nata oak from more to less;and total amount of alcohols and aldehydes matter was water oak, Q. virginiana, quercus phellos, nata oak from more to less. Synthetic all material relative content we found susceptible Quercus virginiana oak released more alkanes and ester matter while the less harm ones released more alcohols and aldehydes matter.3.Two kinds of oak trees under low salt and Q. virginiana under high salt stress could survive, Proline of Q.virginiana leaves adapt to salt stress in 21st day and it also adapt to high salt stress; determination of the whole dynamic process of salt stress in leaves chlorophyll content of Q.virginiana in the high-salt stress were higher than the control; MDA content of Q.virginiana leaves were lower than the control in low-salt within 35 days and high salt in the 21st; Study the resistance to antioxidant activites of the leaves showed the Q.virginiana have a positive reaction to mobilize antioxidation system in order to adapt to salt stress and in the positive response under high salt stress. It was found that:Root-shoot ratio was increase With the increase of salt concentration. The content of Na~+,Cl~- in root were higher than those in aboveground. K~+ /Na~+ in the plants is root<stem<leaf. We found lower salinity stress significantly promoted Q.virginiana rootdevelopment through our research on root morphological parameters.We found after Quercus virginiana introducted in coastal area, it got harm form Anoplophora Chinensis, but we could add proper amount bait-trees in oak forests to decrease Anoplophora chinensis damage to Quercus virginiana. There was responsive relationship between volatile matter of plants and pest damaged extent. It offered theoretical support to research the relationship between forest and pest and find better control pest method. Moreover, Quercus virginiana has higher ability and response to salt stress more positively as saline-alkali soil advantage tree species, its response mechanism mainly through the accumulation of proline, root absorption of harmful ions, the expansion area of root absorption, anti-oxidation system to respond positively so that to absorb more water and nutrients, maintain the normal above-ground plant growth and metabolism in normal physiology.更多还原