The genus «Allium» L. in Italy. XIII. Morphological, caryological and leaf anatomical study in some C-W Mediterranean triploid populations of «Allium trifoliatum» Cyr

Abstract

Abstract Triploid (2n = 3x = 21) sterile populations of A. trifoliatum from Calabria, Sicily, Sardinia, were analysed. Morphological differences were seen but idiograms look very similar in chromosome shape and arm ratio, although the Sardinian plants show a shorter karyotype than the others. Giemsa C-banding reveals a consistent similarity of the C-banding patterns within the tested populations. Neither a highly improbable long-distance dispersal nor the spreading in remote times of the triploid A. trifoliatum can be invoked in explanation of the presence of sterile biotypes in different populations and widely scattered distributions. In the authors' opinion, the polytopic origin may be explained in terms of a casual hybridization phenomenon involving di- and tetraploid Alliums of the «subvillosum-subhirsutum» complex. Flower anomalies and sterility also suggest the hybrid nature of A. trifoliatum in the Italian flora.