Variation in volatile organic compounds in fruits of Iranian Capparis spinosa L. accessions

In the present study, essential oil (EO) content and phytochemical variation were evaluated in the fruits of 10 Iranian Capparis spinosa accessions. The accessions were collected from their natural habitats of Iran and grown together in field conditions. The EOs content ranged from 0.55 to 1.46%. The correlation analysis revealed a significant negative correlation between the EO content and altitude of the sampling locations (P < 0.01; r = −0.84). GC–MS analysis revealed 31 compounds in the EOs of the accessions, mainly being isopropyl isothiocyanate (5.5–13.7%), methyl sulfonyl heptyl isothiocyanate (4.6–15.6%), butyl isothiocyanate (3.6–10.6%), γ-terpinene (4.4–9.2%), and thymol (22.9–37.1%). According to the cluster analysis, the accessions were classified into three groups. Principal component analysis (PCA) demonstrated that the first and second PCs1 confirmed more than 76% of the total variation in the phytochemical components among the C. spinosa samples. Our results revealed that the sampling altitude was the most effective factor in explaining this variation.