The effect of micro-organisms on susceptibility to freezing-damage in petals of cut rose flowers

The susceptibility of cut rose flowers to freezing-damage at sub-zero temperatures was examined. A correlation was found between visible freezing-damage and electrolytic conductance of petal leachate; electrolytic conductance was therefore used to evaluate the extent of freezing-damage.Inoculation of flowers with microbial suspension rendered them more susceptible to freezing-damage. The antibiotic streptomycin reduced the susceptibility to freezing-damage of flowers inoculated with micro-organisms, but did not affect the susceptibility of freshly-cut, untreated flowers.The significance of these findings is discussed in relation to temperature management during storage of cut flowers. It is suggested that freezing-damage is influenced by the presence of bacteria which proliferate during later phases of flower development and act as ice nuclei in the flower.