Sucrose Enhances the Postharvest Quality of Cut Flowers of Eustoma Grandiflorum (Raf.) Shinn.

Abstract

The postharvest life of cut Eustoma grandiflorum flowers is limited by poor bud opening and bent neck in open flowers. Vase solutions containing up to 6% sucrose or glucose improved the quality and vase life of the flowers. The additional carbohydrate improved petal color, increased bud opening, strengthened pedicels, and extended overall inflorescence longevity by up to 8 days. The principal sugar in the petals of open flowers was glucose, with lower concentrations of sucrose and fructose. Presence of sugar in the vase solution greatly increased the concentration of sugars in the perianth of buds and open flowers. Eustoma flowers are affected by exposure to ethylene and pre-treatment with 1-MCP or STS delays final senescence of flowers that have been held in solutions containing sugar. IntroductionLisianthus, or the Texas gentian, Eustoma grandiflorum (Raff.) Shinn., native to the prairie states of North America, is now an important commercial cut flower (Halevy and Kofranek, 1984). Hybrids developed in Japan provide a wide range of colors, color patterns, and both single and double forms. Lisianthus has become very popular as a cut flower, because of the range of colors available, and the fact that each inflorescence comprises a long, straight stem bearing as many as 10 individual flowers. In addition, the plants (which may be annual or biennial depending on the growing environment) bear as many as 10 inflorescences over the production season (Tjia and Sheehan, 1986).Although there have b een many studies of the environmental conditions required for lisianthus production, there has been little examination of the postharvest characteristics of the flowers. Lisianthus is usually harvested commercially when the first one or two flowers on the stem have opened. A good quality inflorescence will usually have ten or more buds and flowers. If the flowers are placed in water, few if any of these buds open, and the longevity of the inflorescence is therefore determined by the life of the open flowers. Frequently, too, the life of the flowers is shortened by premature wilting and bending of the pedicels of the open flowers.In other bud-type cut flowers, it has long been known that bud opening (and consequently display life of the inflorescence) can b e enhanced by the addition of carbohydrate. This can be achieved either by using a postharvest pulse with a high concentration of sugar, as in gladiolus (Mayak et al., 1973) (Han, 1992). Halevy and Kofranek (1984) recommended a pulse with 5-10% sucrose for 24 hours to improve postharvest life of Lisianthus flowers, and Farina et al. compared a number of such pulses. They fo und that pulsing with Chrysal or TOG (with 4% sugar) was ineffective, but that TOG with 10% sugar or 8-HQS with 10% sugar were both effective pulses. Song et al. (1994) tested the effects of STS pre-treatment, and found a modest improvement in bud opening, but also showed that a standard holding solution containing biocides and 2% sugar increased flower life three-fold. Ichimura and Korenaga (199...

Preservative solutions on quality and biochemical aspects of calla lily flowers

“…Both for early-harvest and 1/3 open, the addition of glucose increased flower opening, as already observed for Eustoma grandiflorum (Cho;Celikel;Dodge, 2001). It was also observed that the use of glucose in storage solutions was more effective when compared to sucrose, with effects similar to those observed in Dendrobium 'Youppadeewan' Boonrote, 1990).…”

“…Besides conservation, the control of flower bud opening, percentage of stems with inclined tip and petal coloration was favored by the use of 6% sucrose or glucose in Eustoma grandiflorum (Cho;Celikel;Dodge, 2001). On the other hand, the use of glucose in storage solution was more effective, when compared to sucrose, for floral bud opening and pot life of Dendrobium 'Youppadeewan' Boonrote, 1990).…”

Post-harvest Physiology of Flowers from the Family Gentianaceae

“…Analysis of the sugar content of developing lisianthus flowers revealed the presence of low concentrations of sucrose at all developmental stages and a marked increase in glucose in the open flowers (Cho et al 2001). These authors suggested that the availability of soluble carbohydrate in the vase solution may be important not only for improved opening of the flowers, but also for the synthesis of lignin that makes pedicels stronger, and for the anthocyanins that are the basis for color in these flowers.…”

“…STS pretreatment also delayed the senescence of cut flowers of G. triflora (Zhang and Leung 2001). Cho et al (2001) reported that the treatment with the ethylene action inhibitors STS or 1-MCP did not extend significantly the vase life of Eustoma flowers left in ethylene-free air. However, exposure to ethylene caused a decrease in vase life of the flowers, which was prevented by STS.…”

“…Shimizu-Yumoto and Ichimura (2010b) reported the damage on leaves caused by a high concentration of sucrose and suggested that pulsing at high relative humidity (86 %) decreased leaf damage. Cho et al (2001) found that the longevity of flowers was improved further if sucrose was present continuously in the vase solution. Whereas 1.5 % sugar gave maximal benefit for many flowers, they found continued treatment with 3 % sugar was optimum for Eustoma.…”