This study was carried out at the Ornamental Horticulture Department, Faculty
of Agriculture, Cairo University, during the two successive seasons of 2005 and 2006
with the aim of investigating the effect of preservative solutions and holding periods
on the quality, physiological characteristics and chemical composition of fresh rose
flowers (Rosa hybrida, L. cv. First Red). The flowers were placed in jars containing
one of the following preservative solutions: (1) distilled water, (2) 2% sucrose (Suc) +
200 ppm 8-hydroxy-quinoline (8-HQ) + 250 ppm citric acid (CA), (3) 2% Suc+ 200 ppm
8-HQ + 250 ppm CA + 2 mM 2-mercaptoethanol, (4) 2% Suc + 200 ppm 8-HQ + 250
ppm CA + 0.1% Ca(NO3)2 , (5) 2% Suc + 200 ppm 8-HQ, (6) 2% Suc + 200 ppm 8-HQ
+ 100 ppm CuSO4 or (7) 2% Suc + 200 ppm 8- HQ + 1 mM boric acid.
The results showed that the fresh weight of the flowers and the rate of daily
absorption were decreased after the 3rd day of the holding period, while the
respiration rate was decreased after the 6th day. The rate of increase in the flower
diameter was decreased steadily with prolonging the holding period. On the contrary,
peroxidase activity in the neck of the flower and stem base, was higher on the 12th day
than on the 6th day of the holding period. The total soluble sugars contents in the
petals and leaves, the anthocyanins and carotenoids contents in the petals, as well as
the total chlorophylls and carotenoids contents in the leaves, were lower on the 12th
day than on the 6th day of the holding period, whereas the total soluble phenols
contents in the petals and leaves were higher on the 12th day than on the 6th day of the
holding period.
Most of the tested preservative solutions increased the flower quality and
improved physiological characteristics and chemical composition compared to
distilled water (the control). The preservative solution containing 2% sucrose (Suc) +
200 ppm 8-hydroxy-quinoline (8-HQ) +2 mM 2-mercaptoethanol + 250 ppm citric
acid (CA) can be recommended for use with Rosa hybrida cv. First Red flowers,
since it gave the best results in terms of flower quality, physiological characteristics
and chemical composition, whereas using the preservative solution containing 2%
Suc + 200 ppm 8-HQ + 100 ppm CuSO4 resulted in the lowest quality and
unacceptable physiological characteristics and chemical composition.