Chemical variation among indigenous populations of Foeniculum vulgare var.vulgare in Israel

The composition of hexane extract constituents of ripe mericarps ("achenes" ) of eleven indigenous populations of Foeniculum vulgare var, vulgare (Apia ceae) was studied. Natural populations were selected along a gradient of an nual rainfall from ca. 1000 mm in the northern region down to 125 mm in the Negev desert. Eighteen constituents, with estragole, trans-anethole, fench one, limonene and alpha-pinene as the major components were separated by CC -MS. Characterized by the level of estragole and trans-anethole, four diffe rent groups were obtained: (1) Highest estragole (63 %) and the lowest tran s-anethole (3 %) characterized the population of Mt. Meron; (2) estragole ( 39-47 %) and trans-anethole (17-29 %) in 3 mountainous populations; (3) est ragole (21-29 %) and trans-anethole (38-49 %) in the coastal and lowland po pulations; (4) two exceptional populations with the lowest content of estra gole (ca. 8 %) and high content of trans-anethole (55 and 74 %). A reversed association between the content of estragole and trans-anethole suggests a common precursor. In habitats with a high precipitation, the content of es tragole was high and that of trans-anethole was low, and vice versa under l imited rainfall. It is proposed that the composition of oleoresins of F. vu lgare var. vulgare could be governed by environmental conditions. Neverthel ess, it is not ruled out that genetic variations account for the recorded d ifferences.