茶梢和茶花信息物引诱有翅茶蚜效应的研究

用四臂嗅觉仪和昆虫触角电位仪(EAG)研究了新鲜茶梢和茶花的15种单一挥发性组分对有翅茶蚜的引诱效应。结果表明其中的顺-3-己烯-1-醇、反-2-己烯醛、水杨酸甲酯、芳樟醇、正辛醇和己醛等组分,及茶花主要香气组分橙花醇和烯丙基异硫氰酸酯显著引诱有翅茶蚜。在嗅觉仪生测中,15种组分的10-4 g/ml和102 g/ml两种剂量引诱蚜数的差异明显。EAG反应还表明:①新鲜芽下第一叶气味引出的EAG值最大;②用10-2 g/ml的正己醇、正戊醇、1-戊烯-3-醇、2-戊烯-1-醇、反-2-己烯醛、顺-3-己烯-1-醇和乙酸顺-3-己烯酯按1∶1∶1∶1∶1∶1∶1比例组成“绿叶气味”,也可引起有翅蚜强烈的EAG反应;③蚜害茶梢嫩茎的气味忌避有翅蚜。认为新梢和茶花释放的绿叶气味和水杨酸甲酯可引导有翅茶蚜朝茶梢定位,严重遭受蚜害的茶梢可能释放忌避有翅蚜的信息物质。

Attracting Effect of Volatile Infochemicals from Tea Shoots and Flowers on Winged Tea Aphids

The attracting effects of the fifteen volatile components emitted from tea shoots and tea flowers on alate tea aphid, Toxoptera aurantii, were measured by four-arm olfactometer and electroantennogram (EAG). The result showed that in those odors (Z)-3-hexen-1-ol, (E)-2-hexenal, methyl salicylate, linalool, n-octanol and hexanal as well nerol and allyl isothiocyanate, the main aroma components from tea flowers showed significant attracting effect on the winged tea aphids. The difference in aphid number attracted by 2 doses of 10-4 g/ml and 102 g/ml of 15 components was obvious in olfactometer bioassay. EAG responses showed that: ① the EAG value by the odor from the fresh 1st leaf below the bud was largest; ② Simulating the green leaf volatiles, a mixture composed of 10-2 g/ml n-hexanol, n-pentanol, 1-penten-3-ol, 2-penten-1-ol, (E)-2-hexenal, (Z)-3-hexen-1-ol and (Z)-3-hexenyl acetate according to ratio of 1∶1∶1∶1∶1∶1∶1, could elicit strong EAG responses; ③ the odor from aphid-damaged tender stem repelled tea aphids. It was supposed that the green leaf volatiles and methyl salicylate liberated from tea shoots and tea flowers play a role of attracting lures in alate tea aphids foraging and orienting to tea shoots, and the aphid-damaged tea shoots maybe emit infochemicals to dispel tea aphids.