Cytoplasmic Inheritance

Cytoplasmic male sterility (CMS) is the inability of a plant to produce functional pollen, inherited through the female parent (maternally).
It is caused by changes (rearrangements forming new open reading frames) in the mitochondrial genome, which affect the energy supply needed for pollen development.
Nuclear restorer (Rf) genes can restore fertility.
CMS is widely used in producing hybrid seeds (e.g. maize, rice, sorghum), as it removes the need for manual emasculation.
So genes for cytoplasmic male sterility are generally located in the mitochondrial genome.

In killer strains of Paramecium aurelia, the killer trait is due to kappa particles, which are present in the cytoplasm (they are symbiotic bacteria).
Kappa particles produce a toxin (paramecin) that kills sensitive strains. They are inherited through the cytoplasm, not through nuclear genes, though a nuclear gene K is needed to maintain them (studied by Sonneborn).
So extranuclear (cytoplasmic) inheritance occurs in killer Paramecium.