Effects of temperature and day length on cytoplasmic male sterility in cotton (Gossypium)

Abstract

Temperature and day length were shown to affect, to a major and minor degree respectively, the expression of male sterility in G. hirsutum stocks carrying G. anomalum or G. arboreum cytoplasms. Generally, sterility increased with increasing temperature and day length. Day temperatures above 33°C were required for the consistent expression of male sterility in the sterile A lines tested, while the maintainer, or B, lines became completely sterile at day temperatures above 36¦. It was concluded that while the production of hybrid cotton seed by means of the sterile A lines currently available may be feasible in some tropical areas of Australia, it would be desirable to develop genotypes in which the cytoplasmic male sterile character is stable under a much wider set of temperature regimes.