Wild soybean (Glycine soja) is a valuable genetic resource for soybean improvement. Seed composition profiles provide beneficial information for the effective conservation and utilization of wild soybeans. Therefore, this study aimed to assess the variation in free amino acid abundance in the seeds of wild soybean germplasm collected in Japan. The free amino acid content in the seeds from 316 accessions of wild soybean ranged from 0.965 to 5.987 mg/g seed dry weight (DW), representing a 6.2-fold difference. Three amino acids had the highest coefficient of variation (CV): asparagine (1.15), histidine (0.95) and glutamine (0.94). Arginine (0.775 mg/g DW) was the predominant amino acid in wild soybean seeds, whereas the least abundant seed amino acid was glutamine (0.008 mg/g DW). A correlation network revealed significant positive relationships among most amino acids. Wild soybean seeds from different regions of origin had significantly different levels of several amino acids. In addition, a significant correlation between latitude and longitude of the collection sites and the total free amino acid content of seeds was observed. Our study reports diverse phenotypic data on the free amino acid content in seeds of wild soybean resources collected from throughout Japan. This information will be useful in conservation programmes for Japanese wild soybean and for the selection of accessions with favourable characteristics in future legume crop improvement efforts.

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日本野生大豆（Glycine soja）种质种子氨基酸含量评价及其相关网络分析

野生大豆（大豆) 是大豆改良的宝贵遗传资源。种子组成概况为有效保护和利用野生大豆提供了有益信息。因此，本研究旨在评估日本采集的野生大豆种质种子中游离氨基酸丰度的变化。316份野生大豆种子中游离氨基酸含量为0.965~5.987 mg/g种子干重（DW），相差6.2倍。三种氨基酸的变异系数 (CV) 最高：天冬酰胺 (1.15)、组氨酸 (0.95) 和谷氨酰胺 (0.94)。精氨酸（0.775 mg/g DW）是野生大豆种子中的主要氨基酸，而含量最低的种子氨基酸是谷氨酰胺（0.008 mg/g DW）。相关网络揭示了大多数氨基酸之间的显着正相关关系。来自不同产地的野生大豆种子的几种氨基酸水平存在显着差异。此外，采集点的经纬度与种子总游离氨基酸含量之间存在显着相关性。我们的研究报告了从日本各地收集的野生大豆资源种子中游离氨基酸含量的各种表型数据。该信息将有助于日本野生大豆的保护计划以及在未来豆科作物改良工作中选择具有有利特性的种质。观察到采集点的经纬度与种子总游离氨基酸含量之间存在显着相关性。我们的研究报告了从日本各地收集的野生大豆资源种子中游离氨基酸含量的各种表型数据。该信息将有助于日本野生大豆的保护计划以及在未来豆科作物改良工作中选择具有有利特性的种质。观察到采集点的经纬度与种子总游离氨基酸含量之间存在显着相关性。我们的研究报告了从日本各地收集的野生大豆资源种子中游离氨基酸含量的各种表型数据。该信息将有助于日本野生大豆的保护计划以及在未来豆科作物改良工作中选择具有有利特性的种质。