Abstract:

Effects of dietary amino acids on free amino acid pools of the brown planthopper (BPH),Nilaparvata lugens, were investigated by analyzing both body and honeydew of the insects reared on chemically defined diets with different amino acid profiles. The results were showed as follows: 1) Free amino acid pools in the body of BPH were influenced significantly by diets. Although Met increased, the total quantity of free amino acids in BPH ingesting none of amino acids (NEAA BPH) declined to 63.2% of that in BPH ingesting both essential amino acids (EAAs) and nonessential ones (NEAAs) (EAANEAA BPH). Furthermore, Val, Thr, Ile, Leu, Lys, and Cys decreased markedly. Whereas in BPH kept on diet with only NEAAs (NEAA-BPH), Thr and His were significantly higher than those in EAANEAA-BPH. And Ile, Phe and Arg also had the same concentration as those in the latter. The concentration of Val in NEAA-BPH was markedly lower than that in EAANEAA-BPH, but was similar to that in BPH ingesting only EAAs. Met, Lys and Leu in NEAA-BPH were as low as or even significantly lower than those in NEAA-BPH. 2) The composition of free amino acids in honeydew depended on diet on which BPH was reared. However, the relative concentration of amino acids in honeydew was different from those in diets, and some amino acids not existed in diet were detected in honeydew. It was suggested that six EAAs, i.e. Thr, His, Ile, Phe, Arg and Val,could be synthesized even if BPH could only ingested NEAAs.

Key words: Nilaparvata lugens, chemically defined diet, amino acid, honeydew

摘要： 利用氨基酸组成不同的全纯人工饲料对褐飞虱(Nilaparvata lugens)成虫进行饲养，研究了饲料氨基酸对该虫及其蜜露中游离氨基酸的影响。结果表明：1）饲料对试虫体内游离氨基酸有明显影响。在不能摄入任何氨基酸的试虫体内，游离氨基酸总量降至可以获得全部氨基酸的试虫的63.2%，其中缬氨酸、苏氨酸、异亮氨酸、亮氨酸、赖氨酸和半胱氨酸下降明显，但蛋氨酸增多。在仅能摄取到非必需氨基酸的试虫体内，蛋氨酸、赖氨酸和亮氨酸的含量与不能摄取到任何氨基酸的试虫处在同一水平，甚至明显低于后者；苏氨酸和组氨酸则明显高于可以获得全部氨基酸的试虫，异亮氨酸、苯丙氨酸和精氨酸亦达到了后种试虫的含量水平，缬氨酸的含量虽然低于后者，但与仅能摄取到必需氨基酸的试虫处在同一水平。2）蜜露中的游离氨基酸组成基本与饲料内的相一致，但相对含量有较大差别，而且少数不存在于饲料中的氨基酸可以在蜜露中检测到。文中对必需氨基酸的补偿代谢进行了讨论，初步认为褐飞虱体内至少可以合成苏氨酸、组氨酸、异亮氨酸、苯丙氨酸、精氨酸和缬氨酸等6种必需氨基酸。

关键词: 褐飞虱, 全纯饲料, 氨基酸