Integrated characterization of Greek fennel genotypes through morpho-agronomical characteristics, yield components and phytochemical compounds

Background

Fennel (Foeniculum vulgare Mill.) is a widely cultivated vegetable and aromatic-medicinal plant. In this research, field studies assessed 12 fennel genotypes of diverse origin, comprising 10 Greek accessions and two European commercial varieties, focusing on their morpho-agronomical traits, phenolic compounds and antioxidant activity in the aboveground biomass. Emphasis gave on the post-harvest determination of seed yield and essential oil's (EO's) profile for each genotype.

Results

Multivariate data analysis on both morpho-agronomical descriptors and EO's components demonstrated clear distinction of Greek fennel accessions (groups I and III) from commercial varieties (group II). Accessions of groups I and III were ranked with intermediate values of height, foliage density, leaf length, green color intensity and primary canopy diameter. In addition, fennel accessions differentiated in their EO's yield (ranged from 2.2% to 7.8%), although they exhibited similar qualitative profile. The main EO's compound of group I was trans-anethole, estragole and fenchone for group III, while commercial varieties characterized by high concentration in trans-anethole and fenchone. Variations among genotypes were also demonstrated in the content of total phenolics (7.0–11.6 mg g⁻¹ on dry weight basis, dw) and flavonoids (5.9–12.4 mg g⁻¹ dw), while the antioxidant activity determined by ABTS test, varied from 9.0 to 16.2 mg Trolox equivalents g⁻¹ dw.

Conclusion

The observed variability in morpho-agronomical descriptors and phytochemical profile among fennel genotypes recorded for the first time the potential of Greek native genetic material. The data of this research provides useful information for direct future uses in pharmaceutical industry and for applications in plant breeding programs, aiming to produce new type of fennel varieties.