Postharvest Treatments to Maintain Quality and Control Diseases of Cut Flowers

Main reasons for loss of ornamental value are: flower senescence, deterioration of petals due to microbial caused diseases, loss turgor of petals, stem and leaves by microbial diseases in stalk solution, intolerance of flowers to low temperature and poor postharvest handlings from production to distribution. This project is focusing on pre-and postharvest treatments such as 1-methylcyclopropene (1 -MCP) to extend the shelf life of cut flowers. Vase life of four types of cut flowers was evaluated by measuring color, water uptake, chlorophyll fluorescence and other quality parameters. Both ethylene sensitivity and microbial contamination play important roles in determining the vase life of cut flowers. Treatment of 1-MCP significantly delayed the senescence of cut flowers, especially for carnation, rose and gerbera. Antimicrobial agents were also investigated and showed the potential to reduce the microbial population (bacteria, yeast and molds) in stalk solution and to extend the shelflife of the flowers. The optimal condition for application of microbial agents was established for optimal treatment regime for postharvest management of cut flowers. In order to gain molecular insight into flower senescence, quantitative proteomic studies on cut roses were also conducted and provided insight on molecular basis of flower senescence and effect of 1-MCP treatment. Among the 249 proteins identified and quantified. Five cluster can be created and significant up- and down regulated proteins were identified in response to senescence and 1-MCP treatment. Both applied and fundamental knowledge will be beneficial for industry operation and long term breeding program.