The parameters of the gene effects and the relative significance of the additive, dominant and epistatic gene effects in the inheritance of some yield components (number of ears per plant, ear length and row number in the ear) in intergeneric hybrids Z. mays .times. E. mexicana were determined. The inheritance of the character multiple ear-set is of a considerably simpler type than that of the ear length and the row number. For the multiple ear-set the additive gene effects were more important, and for ear length and row number the dominant gene effects were more important. For a successful transfer of the character multiple ear-set from teosinte to maize, the classic breeding scheme based on additive gene action was most suitable. To improve the ear characters (in the 2nd breeding cycle) recurrent reciprocal selection based on dominant and epistatic gene effects were most appropriate.