Some Factors Affecting the Reversal of Sex Expression in the Tassels of Maize

Abstract

Experiments were carried on in greenhouses with controlled environmental conditions. Reversal of sex expression (development of silks in tassels) is influenced by both heredity and environment. Shorter daily light periods and lower temps. tended to bring about silks in the tassels, the opposite conditions lending toward normal sex expression. The low additional light intensity used during the daylight had little if any effect upon sex reversal. Different inbred strains differed markedly in the degree to which they were affected by environmental changes. The F2 and back-cross progenies from a cross between 2 strains differing in their tendency toward sex reversal segregated typically for a difference in a single major factor pair, the recessive determining the greater tendency to reversal. Genes must interact with the environment in producing the end results, but genic control of a character in any single environment is an adequate basis for concluding that the differentiation of this character is determined genetically.