Morphological and Chemical Evaluation of Fennel (Foeniculum vulgareMill.) Populations of Different Origin

Abstract

A comparison study of 13 fennel (Foeniculum vulgare Mill. var. vulgare) populations of different origins were carried out on the basis of morphological and chemical characters. Relatively stable and variable characteristics were distinguished from evaluating the correlation matrix of the morphological and chemical properties from two successive years. High stability was shown from the morphological aspects such as relative leaf mass, seed size, thousand seed mass (r= 1.000, 0.801, 0.807 respectively); for essential oil accumulation, the presence of (E)-anethole and methyl chavicol were stable characteristics (r=0.923, 0.876). Three distinct intraspecific chemical taxa could be separated based on the cluster analysis of the seed oil: fenchone-rich (31–42% fenchone), methyl chavicol-rich (30–43% methyl chavicol) and (E)-anethole-rich (60–85% anethole) chemovarieties. Within the anethole group, the presence of a further four chemical subvariants of a lower rank (chemoforms) was justified by discriminant analysis. It was also proved that the morphological characters could not be used to support any intraspecific chemical classification. In this respect, the medium strength correlation was found only between the level of essential oil accumulation and the size of seeds (r=0.610).