senescence was significantly promoted by ethylene
at 1 or 20 vl l − 1 when flowers were treated 6 days
after harvest. These results suggest that ethylene
sensitivity increases with flower senescence.
3.3. Effect of STS on the longe6ity and ethylene
production of the cut flower
STS at all concentrations tested significantly
extended flower vase life. The most effective con-
centration was 0.1 mM, at which vase life was
extended by some 5 days (Table 3). Fig. 2 shows
the effect of STS on fresh weight and ethylene
production of flowers with time. The fresh weight
of control flowers increased until 2 days after
harvest, and decreased gradually thereafter. A Values are means of nine replications 9 S.E. and those with
the same letters are not significantly different (PB0.05) by
Duncan’s multiple range test.
24-h treatment with 0.1 mM STS retarded the
decrease in fresh weight. STS delayed the onset of
climacteric ethylene production. A similar result
was also obtained with cv. Azuma-no-kaori (data
not shown). To examine whether STS inhibits
ethylene production of petals, we measured
ethylene evolution from petals 12 days after har-vest. STS markedly inhibited ethylene production
from petals; ethylene production of petals (nl g − 1
FW per hour) was 2.590.3 and 0.790.1 in
control and STS-treated flowers, respectively
(means9 S.E.).
We further examined the effect of aminooxy-
acetic acid (AOA) and h-aminoisobutyric acid
(AIB), inhibitors of ethylene biosynthesis, on the
vase life of cut Eustoma. Treatment with 1 mM
AOA and 5 mM AIB each for 12 h extended the
vase life by 2.8 and 3.3 days, respectively.