Extrachromosomal heredity at maize was highlighted for the first genetic research developed on this plant and reffered to the maternal inheritance of leaf  pigmentation due to the different types of chlorophyll in vairegate plants. It was later revealed that the hereditary transmission of the mutation determined of iojap gene located on chromosome 7 is carried out exclusively in the cytoplasm interaction. The cell nucleus trasfer activity for 12 elite inbred lines on various cytoplasm types has begun in 1992 starting from the assumption that among cytoplasm of different origin could exist differences in genetic value. The research was conducted using inbred isonuclear lines provided by The Laboratory of Maize Breeding from Agricultural Research and Development Station Turda. It has pursued further research on the differences between the isonuclear lines obtained by the transferring of nucleus on different types of cytoplasm and identify cytotipes to interact  with the new nucleus and to improve the maternal transmission ability on certain traits of ears and kernels.

inbred isonuclear lines, the cytoplasm source influence, genetic determinism

Presentation: oral