Physiological and microbiological processes of cut flower senescence in two Australian native genera, 'Acacia' and 'Boronia'

Abstract

Physiological and microbiological cut flower senescence processes in two Australian native genera, 'Acacia' and 'Boronia', were determined. Vase life of the two 'Acacia' spp. tested, 'A. subulata' and 'A. floribunda', was not affected by exposure to ethylene (50 and 500 µL L-¹respectively for 24 h). No detectable levels of ethylene were produced by either species at different stages of floral development. Pulsing with silver thiosulphate (STS) (10.5 mol m-³ for 16.5 h), an inhibitor of ethylene action, did not increase vase life over that in distilled water. However, citric acid (10 mol m-³) significantly improved the vase life of 'A. amoena' compared with distilled water. Cavitation events (audible acoustic emissions, AAE) were recorded for the first time in cut flowers kept in vase solutions. ... Vase solution bacterial numbers had no significant influence on longevity (R² = 0.000). These results indicate an overriding influence of ethylene in flowers which are sensitive to it, and the ambiguous role of bacteria in cut flower senescence.