Cytoplasmic sterility is governed by

Cytoplasmic sterility is governed by Plasma genes.
Cytoplasmic male sterility is under extranuclear genetic control. It shows non-Mendelian inheritance, with male sterility inherited maternally.
In general, there are two types of cytoplasm: N (normal) and aberrant S (sterile) cytoplasms.
And plasma genes are a self-replicating extranuclear determiner of hereditary characteristics.