Gender Determination of Date Palm

Date palm is dioecious, characterized by unisexual flowers located on separate male or female trees. Dioecy has always been an issue in date palm breeding because the sex of the plant cannot be known until it reaches its reproductive stage, which takes 5‒9 years to first flowering. Hence, early sex identification can enhance breeding and genetic improvement success in date palm. The breeding programs help in the selection and identification of superior seedlings of important traits. However, the sex of dioecious plants is usually tedious to identify. Sex determination may not only enhance genetic resources but also gear up breeding programs. No doubt, substantial progress has been made in understanding mechanisms of sex identification in date palm using morphological, physiological, biochemical, and cytological procedures but the discrimination in male and female plants by these techniques is not reliable. Sexuality in plants is regulated by genetic, epigenetic, and physiological mechanisms, and the most specialized mechanism of sex determination is the sex chromosomes. Molecular markers have been applied accurately in date palm breeding programs to differentiate male and female seedlings, but the development of more reliable molecular markers is needed. Hence, this chapter is focused on an understanding of floral biology, genetics of sex, and methods applied for sex determination in date palm.