茉莉酸诱导小麦幼苗对麦蚜取食行为的影响

EFFECTS OF WHEAT SEEDLING INDUCED BY JASMONIC ACID ON FEEDING BEHAVIOUR OF WHEAT APH IDS

茉莉酸可诱导小麦品种郑州891的防御反应,使麦长管蚜Sitobion avenae(F.)和禾谷缢管蚜Rhopalosiphum Padi(L.)的取食行为发生明显改变。尽管此两种蚜虫在正常的小麦植株上取食的EPG各波型参数出现的次数及历时变化较大,但经茉莉酸诱导后,都出现了NP波次数和历时显著增加、E_1与E_2波历时明显缩短、首次出现E_1波时间显著延长以及口针在细胞间穿刺频率明显升高等变化。这说明茉莉酸诱导后,郑州891的取食适合度降低,其机理与茉莉酸诱导产生挥发性的蚜虫取食拒避剂及诱导维管液营养成份的改变有关。试验还证实:麦长管蚜和禾谷缢管蚜的嗅觉和味觉感受器在其对寄主植物适合度的鉴别中共同起作用;植物适合度不能仅由1～2个KPG波型参数作为指示因子,要视具体情况全面分析,才能得出可靠的结论。

The jasmonic acid can induce the defense reaction of wheat variety Zhengzhou 891 to significantly change the feeding behaviour of Sitobion avenae (F.) and Rhopalosiphum padi (L. ) . Despite of the occurrence frequencies and durations of all the EPG ( electric penetration graph) waveform parameters for the two aphids fed on normal wheat plants changed frequently, as they fed on the wheat seedlings induced by jasmonic acid, both the frequency and duration of NP wave were increased obviously, the durations of E1 and E2 waves were notably shortened, the first occurrence of E1 wave was prominently delayed, and the intercellular penetration frequency of stylets has evidently increased. It was indicated that after induced by jasmonic acid, the feeding suitability of Zhengzhou 891 for the two aphid species was reduced, the mechanism of these unfavorable changes to aphid feeding might relate to the volatile repellent of wheat seedling and the change of nutritional solution in vascular bundle of wheat induced by jasmonic acid. Trie authors hold that there must be a coordinate role of the olfactory and gustatory receptors on S. avenae and R. padi for differentiating the feeding suitability of host plant, and the plant suitabih'ty can not be determined only by one or two EPG parameters.