AFLP markers and cytotaxonomic analysis reveal hybridisation in the genus Schoenus (Cyperaceae)

Molecular, cytological and morphological data support the existence of a hybrid population between Schoenus nigricans and Schoenus ferrugineus. This population was found in Northeastern Italy, where sS. nigricans is central with respect to its natural range and S. ferrugineus is marginal, being most common in the Alps and in central and northern Europe. Molecular marker data show that the putative hybrid population is genetically intermediate between nearby populations of the parent species. Cytological evidence confirmed the hybrid nature of this population, as does the almost complete sterility of plants within the population. Although no seeds were produced by the hybrid population, some possibly fertile pollen grains were produced; this suggests that the possibility of introgression between the two species through the hybrids cannot completely be excluded.