Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is the most destructive pest of potato crops and the chemical composition of potato leaves plays an important role in CPB growth and development. Sugars and amino acids can promote CPB development by increasing feeding and flight behaviors, whereas glycoalkaloids are considered as plant defensive compounds to suppress CPB populations. In this study, the effects of nitrogen (N) fertilization on foliar sugar, amino acid, and glycoalkaloid concentrations of two potato cultivars (Russet Burbank and Goldrush) were investigated under controlled conditions. A pot experiment was carried out with five N rates (0, 60, 120, 180, and 240 kg N ha⁻¹) in a randomized complete block design. The 3rd, 4th, and 5th leaves from the top of three randomly selected plants from a plot were collected at 61, 75, 89, and 103 days after planting for the analysis of sugars, glycoalkaloids, and amino acids. Nitrogen fertilization had no significant effect on glycoalkaloid concentrations, however, it quadratically increased foliar sugar and amino acid concentrations. Relatively low sugar and amino acid concentrations were observed at 180 kg N ha⁻¹, suggesting that this N rate may be effective for CPB management. Significant differences in most of the foliar chemicals were observed between two cultivars, warranting further studies to investigate the leaf composition of different potato cultivars under field conditions and their effects on CPB behaviors.

中文翻译：

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控释条件下施氮对两个马铃薯品种叶片化学组成的影响

科罗拉多马铃薯甲虫（Leptinotarsa decemlineata（Say））是马铃薯作物中最具破坏性的害虫，马铃薯叶片的化学成分在CPB的生长和发育中起着重要作用。糖和氨基酸可通过增加进食和逃避行为来促进CPB的发育，而生物碱被认为是抑制CPB种群的植物防御性化合物。在这项研究中，在受控条件下研究了氮肥对两个马铃薯品种（Russet Burbank和Goldrush）的叶糖，氨基酸和糖碱含量的影响。进行了5个N量（0、60、120、180和240 kg N ha ^-1的盆栽实验））的随机完整块设计。在种植后第61、75、89和103天收集了从该地块中随机选择的三株植物顶部的第3，第4和第5叶，以分析糖，糖生物碱和氨基酸。氮肥对糖生物碱浓度无明显影响，但叶酸和氨基酸浓度成倍增加。在180 kg N ha ^-1处观察到相对较低的糖和氨基酸浓度，表明该N比率可能对CPB管理有效。在两个品种之间观察到大多数叶面化学物质的显着差异，有待于进一步研究以研究田间条件下不同马铃薯品种的叶片组成及其对CPB行为的影响。