Differential analysis of volatile metabolites in nine Phalaenopsis varieties based on widely targeted metabolomics

To investigate interspecific differences in aroma-related metabolites and potential precursors in floral tissues of native Phalaenopsis species, this study analyzed floral tissues of nine Phalaenopsis species at full bloom using derivatized GC-MS-based widely targeted metabolomics. PCA showed that PC1 and PC2 explained 22.7% and 9.2% of the total variation, respectively, with a cumulative contribution rate of 31.9%, indicating interspecific differences in floral metabolic profiles among the nine Phalaenopsis species. Heatmap analysis of key aroma-related metabolites showed differential accumulation of L-phenylalanine, L-tyrosine, salicylic acid, benzoic acid, 4-hydroxyphenylethanol, phenylacetaldehyde, and 3-hydroxycinnamic acid among different species. KEGG enrichment analysis indicated that the differential metabolites were mainly involved in amino acid metabolism, carbon metabolism, phenylalanine metabolism, and phenylpropanoid biosynthesis. These results demonstrate that aromatic amino acid metabolism, phenylpropanoid-related metabolism, and basic carbon–nitrogen metabolism jointly contribute to the interspecific differences in aroma-related metabolites and their precursors in Phalaenopsis, providing a metabolomic basis for subsequent direct analysis of floral volatiles and fragrance trait improvement.