Characterisation of the volatile compounds in nine varieties and three breeding selections of celery using GC–IMS and GC–MS

Celery (<i>Apium graveolens</i> L.) is a popular vegetable crop planted worldwide. In this study, the volatile compound characteristics of three <i>A. graveolens</i> var. <i>dulce</i> varieties (type D), and six <i>A. graveolens</i> var. <i>secalinum</i> varieties (type S), and three breeding selections were analysed and 41 and 73 volatile compounds were identified using GC-MS and GC-IMS, respectively. The results showed that type S emitted more terpenes and phthalides than type D varieties. Both GC-MS and GC-IMS could discriminate between type S and type D. Six potential biomarkers, i.e., sabinene, (<i>E</i>)-caryophyllene, α-phellandrene, limonene, γ-terpinene, and hexanal, were identified using both models. Both GC-MS and GC-IMS could discriminate between parent and breeding selection. The relative contents of seven (GC-IMS OPLS-DA model) and ten (GC-MS OPLS-DA model) volatile compounds showed over-parent heterosis. This study provides a technical reference for distinguishing celery varieties in the same habitat and preliminarily reveals the aroma relationship between breeding selections and their parents.