Abstract: The preservation effects of pretreatment with nano-silver（NS），a new-type anti-bacterial
agent，on cut carnations（Dianthus caryphyllus‘Master’），and its efficacy in alleviating bacterial blockage
in their stems were investigated. The results showed that pretreatment with 150–300 mg · L-1 NS for 1 h
to cut carnations before placed in vases containing de-ioned water could significantly prolong their vase
life，increase the flower diameter，improve water uptake，and maintain relative fresh mass. The best
concentration of NS was 250 mg · L-1. It was also found that pretreatment with 250 mg · L-1 NS could
significantly delay the decline in hydraulic conductance in the stem-ends of cut carnations. Further
determination using Inductively Coupled Plasma-Atomic Emission Spectrometry demonstrated that NS
mostly remained within the lowermost part of the cut carnation stem throughout the vase period. In
addition，the observation results of Scanning Electron Microscopy certified that pretreatment with 250
mg · L-1 NS could effectively alleviate bacterial blockage in stem-ends of cut carnations.

Key words: Dianthus caryphyllus, cut flower, nano-silver, antibacterial effect, stem-blockage