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.