Herbivore-induced emissions of maize volatiles repel the corn leaf aphid, Rhopalosiphum maidis
Herbivore-induced emissions of maize volatiles repel the corn leaf aphid, Rhopalosiphum maidis
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DOI：
10.1023/a:1003200108763
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发表时间：
1998-05-01
影响因子：
1.9
通讯作者：
Dorn, S
中科院分区：
文献类型：
--
作者：
Bernasconi, ML;Turlings, TCJ;Dorn, S
当玉米植株受到机械损伤，并用毛虫返回剂处理受损部位时，玉米植株会释放出一种特定的混合挥发物。众所周知，这些挥发物对食草动物的天敌具有诱惑力。我们假设植物挥发物是诱导植物防御的一部分，食草动物也会受到气味的影响。在实验室和半田间研究中，这一假说被验证为麦长管蚜(Rhynchota，Sternorrincha，Aphdidae)。在Y管嗅觉仪中，当与干净的空气或用返回剂处理的植物进行测试时，更多的蚜虫选择健康、未受损害的玉米幼苗的气味。当测试处理过的植物的气味时，更多的人选择清洁的空气。在田间试验中，在8株盆栽玉米植株的圆圈中心释放了麦长管蚜。每个圈内的四株植物受到损害，并用毛虫反流剂进行处理，而其他植物则没有受到伤害。在释放蚜虫后的不同时间段，统计每株上的蚜虫数量。在经过处理的植物上发现的有翼和无翅的蚜虫比在健康植物上发现的要少得多。我们认为草食动物可能会被气味所排斥，因为它们可能表明：1)植物已经开始产生有毒化合物；2)植物上存在潜在的竞争对手；3)植物对寄生虫和捕食者有吸引力。蚜虫可能对诱导的玉米挥发物特别敏感，因为植物释放的主要化合物之一是(E)-β-法尼烯，这是一种常见的警报信息素。收集和分析被碾碎的R.maidis发出的气味证实，当受到压力时，它也会释放(E)-β-法尼烯。这些结果在植物防御策略的背景下进行了讨论，并讨论了它们可能用于控制害虫的可能性。
When maize plants, Zea mays L., are mechanically damaged and the damaged sites are treated with caterpillar regurgitant, the plants will release a specific blend of volatiles. It is known that these volatiles can be attractive to natural enemies of herbivores. We hypothesise that the plant volatiles constitute part of the induced plant defence and that herbivores will be affected by the odours as well. In laboratory and semi-field studies this hypothesis was tested for the aphid Rhopalosiphum maidis (Fitch) (Rhynchota, Sternorrhyncha, Aphididae).In a Y-tube olfactometer significantly more aphids chose the odour of healthy, undamaged maize seedlings when tested against clean air or plants treated with regurgitant. Clean air was chosen more often when tested next to the odour of treated plants. This apparently repellent effect of the odour of treated plants was significant for winged aphids, but not for the wingless aphids.In field experiments aphids were released in the centre of circles of eight potted maize plants. Four plants in each circle were damaged and treated with caterpillar regurgitant while the other plants were left unharmed. At different intervals after aphid release, the number of aphids was counted on each plant. Significantly fewer winged and wingless aphids were found back on treated plants than on healthy plants.We suggest that herbivores may be repelled by the odours because they could indicate that: 1) the plant has initiated the production of toxic compounds; 2) potential competitors are present on the plant; 3) the plant is attractive to parasitoids and predators. Aphids may be particularly sensitive to induced maize volatiles because one of the major compounds emitted by the plant is (E)-beta-farnesene, which is a common alarm pheromone for aphids. Collections and analyses of the odours emitted by crushed R. maidis confirmed that it too emits (E)-beta-farnesene when stressed. The results are discussed in context of plant defence strategies and their possible exploitation for the control of pest insects.