Bulb onion (Allium cepa L.) contains several functional components such as quercetin glycosides, a type of flavonoid. The quercetin content of bulb onion has been determined at harvest and storage; however, little is known about the changes in quercetin accumulation during development. In this study, two yellow onion varieties, ‘Momiji No. 3’ and ‘Quergold’, which differ in quercetin content at harvest, were grown on lowland soil following spring sowing in 2018 and 2019. Then, the changes in quercetin accumulation and composition in the bulbs and leaf blades from the seedling stage to harvest were evaluated. In both years, quercetin accumulation in the bulbs followed a similar trend, with ‘Quergold’ tending to have a higher quercetin content than ‘Momiji No. 3’, except for two weeks following transplanting. Significant differences between the quercetin contents in the two varieties were observed at harvest. The content of quercetin-4'-glucoside (Q-4'-G) was the same or higher than that of quercetin-3,4'-diglucoside (Q-34'-DG) throughout development, except on October 6, 2018, and July 29, 2019, in both varieties. Meanwhile, the quercetin content per bulb increased with bulb formation in both varieties. In contrast, quercetin accumulation in the leaf blades was lower than that in the bulbs throughout development in both years. An increase was observed from July, with accumulation of Q-34'-DG dominating until early July, whereafter accumulation of both Q-34'-DG and Q-4'-G was observed until harvest. Overall, these findings suggest that accumulation of quercetin glucoside content varies dramatically with growth, differing between onion bulbs and leaf blades.

球茎洋葱（Allium cepaL.) 含有多种功能成分，例如槲皮素糖苷，一种类黄酮。球茎洋葱的槲皮素含量已在收获和储存时确定；然而，人们对发育过程中槲皮素积累的变化知之甚少。本研究在 2018 年和 2019 年春播后在低地土壤上种植了收获时槲皮素含量不同的两个黄洋葱品种“红叶 3 号”和“Quergold”。然后，槲皮素积累和组成的变化对从苗期到收获的球茎和叶片进行了评估。在这两年中，鳞茎中槲皮素的积累遵循类似的趋势，除了移植后两周外，“Quergold”的槲皮素含量往往高于“Momiji No. 3”。在收获时观察到两个品种的槲皮素含量之间存在显着差异。除2018年10月6日外，槲皮素-4'-葡萄糖苷（Q-4'-G）的含量在整个开发过程中均与槲皮素-3,4'-二葡萄糖苷（Q-34'-DG）相同或更高和 2019 年 7 月 29 日，两个品种。同时，随着两个品种的鳞茎形成，每个鳞茎的槲皮素含量增加。相比之下，在这两年的整个发育过程中，叶片中槲皮素的积累量低于鳞茎中的积累量。从 7 月开始观察到增加，Q-34'-DG 的积累在 7 月初占主导地位，此后观察到 Q-34'-DG 和 Q-4'-G 的积累直到收获。总体而言，这些发现表明槲皮素葡萄糖苷含量的积累随生长而显着变化，