【作者】 刘金华；

【导师】 高其康；

【作者基本信息】 浙江大学 ， 植物保护学， 2014， 硕士

【摘要】 印度梨形孢Piriformospora indica是从印度塔尔沙漠植物中分离出来的一种植物根部内生真菌,它能够定殖于多种植物的根部与其形成互作。印度梨形孢不仅能够促进植物的生长,增加生物量和提高植物的产量,而且还能够诱导植物产生对生物胁迫和非生物胁迫的抗性。油菜蚜虫是为害油(Brassica napus L.)最严重的害虫,在我国主要为桃蚜(Myzus persicae)、.萝卜蚜(Lipaphis erysimi)和甘蓝蚜(Brevicoryne brassicae L.)三种,油菜蚜虫繁殖力极强,取食量大,成、若蚜在油菜顶端或嫩叶背面刺吸汁液,使受害叶变黄卷缩,植株生长不良,影响抽苔、开花、结实。这三种蚜虫在取食危害的同时,还可通过口针,向油菜传播多种病毒,严重影响油菜的产量。本论文通过对印度梨形孢定殖油菜(高油605)根系获得的共生体油菜的研究,探明印度梨形孢定殖对油菜抗蚜性的影响,并对其相关机理进行了初步研究,主要结果如下：1.共生体油菜能够显著驱避萝卜蚜对油菜寄主的选择大棚拟自然环境下和实验室人工环境下分别进行的蚜虫双向选择试验结果(P<0.01)基本一致,均表明共生体油菜上蚜虫的数量极显著低于对照油菜。油菜叶碟蚜虫双向选择试验的结果也同样表明共生体油菜上蚜虫的数量显著低于无印度梨形孢定殖的油菜,且部分蚜虫在取食有印度梨形孢定殖的油菜一段时间后转向选择无印度梨形孢定殖的油菜。2.共生体油菜释放的挥发物的含量发生显著变化利用顶空动态吸附装置收集挥发物,GC-MS分析鉴定共生体油菜和对照油菜挥发物成分,结果表明共生体油菜单位时间释放的挥发物的总量极显著高于对照油菜,其中差异显著的化合物经数据库搜索比对发现α-pinene、terpinolene、 β-thuj ene、camphor、α-cedrene以及β-caryophyllene的相似度在90%以上。进一步用对应的标准品单体在相同条件下进行GC-MS验证,结果证实确是上述6种化合物。3.萝卜蚜对化合物的行为反应差异明显萝卜蚜对上述6种化合物单体的行为反应表明,α-pmene对萝卜蚜具有极显著的吸引作用,camphor对萝卜蚜具有极显著的驱避作用,其余单体则对萝卜蚜没有显著的作用。萝卜蚜对3种模拟实际油菜挥发物比例的混合物的行为反应表明,混合物1(模拟共生体油菜挥发物的比例),混合物2(模拟对照油菜挥发物的比例)以及混合物3(camphor:α-pinene为2：1)均能显著影响萝卜蚜对寄主油菜的选择,具驱避作用。化合物的浓度对萝卜蚜的影响差异显著,低浓度(10-6g mL-1)条件下混合物1对萝卜蚜的驱避作用最显著,且这一浓度的量(10ng)远低于实际1h共生体油菜释放的挥发物的量(147ng)。高浓度(1g mL-1)条件下camphor对萝卜蚜的驱避作用最显著。而混合物2在低浓度下对萝卜蚜没有驱避作用,在高浓度下(大于10-2g mL-1)则对萝卜蚜具有显著的驱避作用。4.共生体油菜显著减少萝卜蚜的取食量共生体油菜除了挥发性化合物的变化影响萝卜蚜对寄主油菜的选择外,也极显著降低萝卜蚜在油菜上的取食量,比对照油菜少32.7%,这可能与y-氨基丁酸的量显著提高相关。更多还原

【Abstract】 Piriformospora indica is a root endophytic fungus, which was isolated from Thar Desert in India, forms an association with roots of many plant species. The fungus has captable to stimulate growth, increase biomass and enhance production of the hosts. It also confers the host resistance against abiotic and biotic stresses.Aphid is the most serious pest on rape, mainly for the Myzus persicae, Lipaphis erysimi and Brevicoryne brassicae L.. Because of the strong fecundity, high feed intake and spreading various viruses, aphids cause serious impact on rape yield.In this thesis, Piriformospora indica-rape symbiont was established to confirm the resistance to aphids in Brassica napus L. conferred by Piriformospora indica and preliminarily study the mechanisms. The salient findings of the research are:1. P. indica inoculated B. napus significantly repelled aphidsRapes colonized by P. indica significantly interfered the positioning of aphids to rapes. Aphid dual-choice assay in the greenhouse and laboratory artificial environment indicated that P. indica inoculated B. napus (Bn+Pi) significantly repelled aphids. And aphid dual-choice assay of rape leaf discs also indicated that Bn+Pi significantly repelled aphids. Meanwhile some aphids turned to P. indica-free B. napus(Bn-Pi) after eating Bn+Pi.2. Volatiles emitted by Bn+Pi were significantly different to that emitted by Bn-PiVolatiles analysis showed the total amount of volatiles emitted by100g Bn+Pi plant per hour was significantly higher than Bn-Pi plant. The volatile compounds, whose amount had significantly different between Bn+Pi and Bn-Pi plants, belonging to monoterpenes and sesquiterpenes, were a-pinene, terpinolene, camphor, β-thujene, a-cedrene and β-caryophyllene.3. L. erysimi had different reactions to volatile compoundsThe result of four-sector olfactometer assay indicated that single component α-pinene attracted L. erysimi, camphor repelled L. erysimi, and other components had no effects to aphids. Blend1, blend2and blend3also had significant repellent to aphids. The quantity of the components in the volatiles was also responsible for the differential attraction and repellency of L. erysimi. When the concentration was low (10-6g mL-1), blend1had the strongest repellency to L. erysimi, while camphor most repelled L. erysimi under high concentration (1g mL-1).4. Bn+Pi significantly reduced the food assimilation of aphidThe food assimilated by L. erysimi on Bn+Pi decreased32.7%compared to Bn-Pi. And it may be relevant to the significantly increasing of γ-aminobutyric acid in Bn+Pi plant.更多还原