Hormonal control of sex expression of cucumber (Cucumis sativus L.) with the identification of sex linked molecular marker

Abstract

Sex differentiation in plants is closely related to the process of plant growth and development. The mechanism that regulates the transition in flowering plants from the vegetative state to reproductive development is poorly understood because the flowering physiology is difficult to study using traditional methods. In the present study, tissue culture system was used as a potential tool to study the sex determination of cucumber to reduce the influence of environmental factors. Major role of gibberellic acid and cytokinins in the regulation of sex expression of cucumber were demonstrated. Gibberellic acid was associated with male sex expression whereas cytokinins found to be associated with the female sex expression. However 6-Benzyl adenine was found to induce hermaphrodite flowers. In the present study, in vitro flowering with different sex expression as well as sex conversion correlates the established fact that minor changes in the balance between phytohormones in the plants with the same genotypic conditions can result in the development of one sex or another. To understand the molecular background of sex expression in cucumber, random amplified polymorphic DNA (RAPD) marker technique was adopted. The result shows unique banding pattern for genome fingerprinting at an early stage of analysis. Two sex linked markers namely OPS250-11 and OPS600-11 were scored for male and bisexual individuals respectively, that are helpful to understand the developmental biology and stable sex expression of cucumber.