Variabilità cariologica inLimonium bonifacienseArrigoni et Diana (Plumbaginaceae)

Karyological variability of the uniqueLimonium bonifaciensepopulation from Corsica has been studied. Pollen and stigma turned out to be monomorphic, so this population is autosterile. Pollen grain and seedling morphology anomalies have also been observed. Such a karyologic variability, never found inLimoniumnor in other plants, concerns both chromosome number and karyotype (sometimes a serie n=xo=9 has been found, with bigger size chromosomes and one large metacentric). The following karyologic situation becomes evident from karyotype studies: 34.69% have 2x+x=27; 34.69% have 2x+xo=27, 2x=18 and xo=9; 10.20% have 2x+x+xo=36; 6.12% have 2x+x+xo=36, 2x+x=27, 2x= 18 and xo=9; 2.04% have 2x= 18; 14.28% are aneuploid. Even if definitive conclusions on the nature and causes of such a variability can not yet be drawn, some considerations can be made to explain the results of this study.L. Bonifaciense, being probably of hybrid origin, shows facultative meiosis and apomixis, is also monomorphic, autosterile and may not yet be genetically stabilized. Thus, as a hypothesis, it may receive compatible pollen from another species ofLimonium. As a consequence, di-hybrid genome embryos are sometimes formed, whose cells try to restore its own genome by segregating the heterogeneous ones.