Karyological investigations on Nasturtium officinale R.Br. in Tuscany and considerations on its Italian populations in a global perspective

We investigated the karyology of two Tuscan populations of Nasturtium officinale, one of which having individuals of anomalous large sizes. All the two populations proved to have 2n = 32. This is the second national karyological datum for Italy after a previous one for Sicily. In the investigated material we found that the phenomenon of chromosome aggregation is frequent. Literature data analysis allowed to discuss these findings in the global context of the complicated cytogeographic arrangement of this taxon, and to consider Italian plants with 2n = 32 as tetraploid.