The Effect of 1-methylcyclopropene and Cobalt Chloride on Some Vegetative and Reproductive Characteristics of gynoecious Cucumber

Greenhouse cucumbers are gynoecious, but in the bisexual stage of flower bud, the sex of flowers can be changed. Therefore, induction male flower is necessary for breeding programs and seed production of gynoecious cucumbers. In this study, the response of flower sex change of gynoecious greenhouse cucumber to 1-methyl cyclopropene (1-MCP) and cobalt hloride was studied. The tretment of cucumber seedlings at two true leaf stage by spraying cobalt chloride (10, 20 and 40 mg.l-1) and 1-MCP gas (for 24 hours with 1 and 2 µl.l-1) showed that, 1-MCP increased plant height, leaf number, leaf length, leaf width and leaf tail diameter compared to the control.  However, cobalt chloride reduced stem diameter, leaf number, leaf tail diameter and Female flower number compared to the control. The different concentrations of 1-MCP didnot affect on the female flowers. The results showed that, the concentration of 40 mg.l-1 cobalt chloride and 1-MCP treatments in some plants 1 to 2 male flowers induced in the first and second nodes. Pollen seed germination test showed that the male flowers formed were normal and the development of stamens was complete. Totally, the inhibitory mechanism of 1-MCP is similar to silver ion in the biosynthesis pathway of ethylene, to better understand the molecular mechanism of flower sex change in cucumber in relation to ethylene, it is recommended to use other concentrations of 1-MCP in the lines of gynoecious and monoesiouse.