Karyological and molecular analysis of Leucanthemum (Compositae, Anthemideae) in Corsica

Abstract

Karyological, flow-cytometric and molecular analyses indicate that the genus Leucanthemum Mill. (Compositae, Anthemideae) is represented in Corsica (Corse) by two species: the tetraploid L. ircutianum DC. and the hexaploid L. corsicum (Less.) DC. The indication of the occurrence of the diploid L. vulgare Lam. on the island and of a tetraploid chromosome number for L. corsicum, given in former treatments of the genus for Corsica, could not be corroborated. AFLP fingerprinting further suggests that the infraspecific taxonomy of L. corsicum with two subspecies (L. corsicum subsp. corsicum and subsp. fenzlii) and three forms (L. corsicum f. corsicum, f. pinnatifidum and f. eschenlohrianum), which is mainly based on differences in the degree of leaf dissection, is not backed by genetic discontinuities. Owing to the observed little variation in leaf dissection within populations in the wild and the constancy of these features under cultivation, we propose the rank of varieties to taxonomically acknowledge these different stages in the broad spectrum of leaf-dissection grades exhibited by L. corsicum. As a consequence, the two new combinations L. corsicum var. eschenlohrianum (Gamisans) Vogt, Hugot & Oberpr. and L. corsicum var. fenzlii (Gamisans) Vogt, Hugot & Oberpr. are proposed.