Abstract: To investigate the influence of geographical and germplasm factors on amino acid composition and content in Pseudostellariae Radix.The content of 20 amino acids were determined by HPLC with pre-column derivatization and for the multivariate statistical analysis.Sequencing analysis showed that there were differences in Pseudostellariae Radix between the same germplasm of different regions and the same region of the different germplasm.The principal components analysis showed that glutamic acid,threonine,methionine,isoleucine,proline and γ-aminobutyric acid were characteristic amino acids in Pseudostellariae Radix.Comprehensive evaluation showed that ZS2 cultivated in Jiangsu Jurong had the better quality in terms of amino acids.Oneway ANOVA showed there was significant correlation between region and the characteristic amino acids.The region was the main factor affecting the differences of amino acids in Pseudostellariae Radix.This study provided a scientific basis for the investigation of the influence of the quality formation mechanism of Pseudostellariae Radix.

Key words: Pseudostellariae Radix, idioplasm and cultivation regions, HPLC, amino acids, multivariate statistical analysis