不同寄主植物上瓜蚜体内主要构成成分的变化

为揭示寄主植物与瓜蚜Aphis gossypii相互作用的机理, 采用微量凯氏定氮法、索氏提取法、蒽酮比色法、盐酸水解法和气相色谱法分别测定了黄瓜、南瓜、搅瓜、瓢葫芦和哈密瓜等5种寄主植物对瓜蚜体内粗蛋白、脂肪、糖、氨基酸和脂肪酸等主要构成成分的影响。结果表明, 不同寄主植物上瓜蚜体内上述主要构成成分均存在显著差异; 瓜蚜体内主要构成成分以粗蛋白含量最高, 占虫体干重的35.40%~45.25%, 其次为脂肪（24.01%~30.33%）, 最低为总糖（4.09%~7.91%）. 瓜蚜体内含有18种氨基酸, 其中谷氨酸含量最高（5.15~6.97 mg/100 mg）, 其次为天门冬氨酸（3.75~5.33 mg/100 mg）, 再次为亮氨酸（2.59~3.60 mg/100 mg）, 最少为半胱氨酸（0.44~0.49 mg/mg）。瓜蚜体内含有8种脂肪酸。 除瓢葫芦外, 其他4种供试寄主植物上瓜蚜体内棕榈酸含量最高（10.53%~15.55%）, 其次为肉豆蔻酸（3.32%~9.93%）, 亚麻酸含量最低（0.04%~0.17%）。瓢葫芦上瓜蚜体内肉豆蔻酸含量最高, 为16.20%, 其次为棕榈酸（7.15%）。瓜蚜体内饱和脂肪酸含量占虫体干重的20.08%~27.72%, 而不饱和脂肪酸只占2.58%~3.84%。结果提示寄主植物对瓜蚜体内主要构成成分均有显著的影响。

Changes in major body constituents of Aphis gossypii Glover(Homoptera:Aphididae)on different host plants

In order to understand the interactive mechanisms of Aphis gossypii Glover and its host plants, the changes in major body constituents, viz. Crude protein, fat, sugar, amino acid and fatty acid, of A. Gossypii on five host plants, viz. Cucumis sativus, Cucurbita moschata var. Melonaeformis, Cucurbita pepo var. Medidlosa, Lagenaria siceraria var. Turbinata and Cucumis melo var. Saccharinus, were investigated by microKjeldahl method, Soxhlet extraction, anthrone colorimetry, hydrochloric acid hydrolysis method and gas chromatography, respectively. The results showed that the contents of the above constituents were significantly different among the aphids reared on different host plants. The dried aphids contained 35. 40%-45. 25% crude protein, 24.01%-30.33% fat and 4.09%-7.91% sugar depending on the host plants. Eighteen amino acids existed in the body of the aphid, mainly glutamate (5.15-6.97 ing/100 mg, dry weight), aspartic acid (3.75-5.33 mg/100 mg) and leucine (2.59-3.60 mg/100 mg), and the least was cystine (0.44-0.49mg/100 mg). There were 8 kinds of fatty acids in the aphids. The highest content was palmitic acid (10.53%-15. 55%), then myristic acid (3. 32%-9. 93%), and the least was linolenic acid (0.04%-0.17%) in the aphids fed on the other four host plants except for L. Siceraria var. Turbinata, on which the most abundant was myristic acid (16. 20%) and the second abundant palmitic acid (7. 15%). The dried aphids contained 20.08%-27. 72% saturated fatty acids and 2. 58%-3. 84% unsaturated fatty acids. The results suggest that the host plants affect significantly the major body constituents of A. Gossypii.