The effect of water stress and pretreatment with sucrose on ethylene sensitivity of cut carnation flowers (original) (raw)
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A screening test for the determination of cut flower longevity and ethylene sensitivity of carnation
Horticultural Science, 2017
Strategies to prevent postharvest losses include the use of genotypes that have a longer life. The objective of this study was to develop a screening test for the estimation of cut flower postharvest life and the response to exogenous ethylene of different carnation cultivars at an early stage of plant growth. Ethylene sensitivity and production in different cut flower cultivars was evaluated, and a similar response in the vegetative stage was studied. Also, the possible relationship between the morphological parameters of cuttings and flower postharvest life was studied. Ethylene production of cuttings may be a useful tool for estimating ethylene production of cut flowers. There is a strong relationship between cut flower vase life and the root length of cuttings, as well as cut flower ethylene sensitivity and the number of internodes the cuttings have. Applications of exogenous ethylene to cutting cultivars have an effect on the growth parameters of the cuttings, but the response ...
Stress-Induced Ethylene Production in Flower Parts of Cut Carnation Flowers cv. Light Pink Tasman
1997
Ethylene is a plant hormone with endogenous production associated with the process of senescence for a number of cut flowers. Different stressogenic factors, including signals such as pollination, exogenous ethylene and auxins have been found to be associated with the increase in ethylene emission and a specific tissue response has been documented. The present study was undertaken with the aim to investigate the role of external stress stimuli such as wounding and desiccation and the effect of IAA, NAA and 2,4-D and ethylene treatments on ethylene evolution of separated carnation flower parts. The experiments were conducted with cut carnation flowers (Dianthus caryophyllus L.) cv. Light Pink Tasman harvested in commercial maturity. Two groups of flowers were used: "A"-STS and non-STS pretreated. The flower heads were excised and dissembled to petals, ovaries and styles and young leaves from cuttings were taken. Ethylene production was measured by GC. The results showed that the reaction of component flower parts differed depending on the treatment used: wounding and desiccation accelerated the ethylene production in ovaries and styles; ethylene exposure resulted in enchanced ethylene emission of petals and auxin induced remarkable amount of ethylene released from leaves.
Postharvest Physiology of Cut Carnation Flowers
The most important challenge for postharvest researchers is to slow the processes controlling flower death to enable cut flowers with longest vase life and best quality to reach distant markets. Senescence of carnation is normally characterized by a climacteric-like pattern of ethylene production in which a surge in ethylene production is followed by a decline. Therefore, ethylene sensitivity is an important determinant in flower longevity of carnations. Nevertheless, postharvest losses in this flower result mainly from exposure to unfavourable conditions that accelerate ethylene production or render the flower more sensitive to ethylene, therefore careful postharvest handling is essential to maximise vase life and maintain flower quality. Pre-treatment of carnations with sugars and anti-ethylene agents such silver thiosulfate (STS) and 1-methylcyclopropene (1-MCP) result in a desirable increase in postharvest longevity. Floral preservatives that contain a proper amount of sucrose and different anti-ethylene products (inhibitors of ethylene biosynthesis or action) not only delay petal senescence and decrease tissues' sensitivity to ethylene, but also significantly improve qualitative or aesthetic characteristics of cut carnations. As cut flowers are often exposed to ethylene in the postharvest shipping and marketing environment, it would be useful to develop cultivars that are insensitive or less sensitive to ethylene. Carnations have now been genetically modified through the addition of a mutation of the ethylene binding site which makes them insensitive to ethylene. The breeding of cultivars with genetically superior vase life appears to be a very efficient approach for satisfying the consumer's quality expectations.
The physiological and molecular responses of carnation flowers to high temperature
Postharvest Biology and Technology, 1998
Carnation (Dianthus caryophyllus cv. 'White Sim') flowers were subjected to a heat treatment to investigate the physiological and molecular effects of high temperatures on flower senescence. Flowers were exposed to 44°C for 24 h in the dark. Control flowers were held at 23°C. In heat-treated flowers the ethylene climacteric occurred 120 h after treatment, a delay of 24 h when compared to control flowers. Maximum ethylene production was decreased from 44 to 31 nl g − 1 h − 1 in heat-treated flowers. Northern blot analysis of the ethylene biosynthetic genes ACC synthase and ACC oxidase indicated that the accumulation of these mRNAs is delayed by 24 h in heat-treated flowers. The accumulation of senescence-related (SR) genes followed a similar pattern. Further investigation revealed a decreased responsiveness to exogenous ethylene and a reduced capacity to produce ethylene in petals from heat-treated flowers. Northern blot analysis again revealed a delay in the accumulation of ACC synthase and ACC oxidase transcripts. SR gene expression induced by ethylene, however, was not affected by the heat treatment. The beneficial effects of high temperatures, a delay in ethylene production and reduced responsiveness to ethylene, may lead to horticultural application.
1997
Senescence and stresses have been documented to promote ethylene synthesis in ethylene-sensitive flower such as carnations. Thus the inhibition of ethylene evolution might lead to activation of other metabolic reactions. Present experiments were undertaken with cut at bud stage spray-carnation (D. caryophyllus f. spray, Hort.) flowers, cv. Regina and cv. Naslada. Tested cultivars are a new breeding result at Institute of Floriculture, Sofia. After harvest treatments with AOA and sucrose were applied using AOA as senescence retarding agent. The goal was to trace how proline content and α-amylase were affected when ethylene synthesis was inhibited. Considerable extension of vase-life (about 128% over the control) and bud opening to fully open flowers were established in response to AOA and AOA+sucrose treatments. A stimulation α-amylase activity was noticed at the beginning of post-harvest petal growth. In response to AOA treatment the activity of α-amylase and the content of free proline remained on a lower level which indicated less exhibited stress reaction and this was associated with a retardation of senescence processes. The studied metabolic events showed a specificity of cultivar behaviour.
Physiologia Plantarum, 1993
In cut carnations (Dianthus caryophyllus L, cv, Cally). petal seneseence was associated with a climacteric pattern in ethylene production and an increase in ethylene sensitivity during the preclimacteric stage, TTie inerease in ethylene sensitivity was caused by short-chain saturated fatty acids (C7 to C,u) produced in the petals during the early stages of senescence. Pollination or application of octanoic acid to the styles of unpollinated flowers resulted in a sudden increase in ethylene sensitivity and a marked acceleration of senescence. Treatment with silver thiosulfate (STS) resulted in a suppression of ethylene sensitivity and a marked reduetion in the levels of these fatty acids. However, even in STS-treated flowers pollination or treatment with octanoic acid gave rise to a drastic increase in ethylene sensitivity Exposure of carnation flowers to 2.5-norbornadiene (NBD) vapours resulted in a dramatic suppression of ethylene sensitivity which was also overridden by stylar application of octanoic acid. Exposure to NBD suppressed the inerease in ethylene sensitivity caused by treatment with octanoie acid. It appears that short-chain saturated fatty aeids increased ethylene sensitivity by increasing the ability of the tissue to bind ethylene.
Planta, 1980
The rise in ethylene production accompanying the respiration climacteric and senescence of cut carnation flowers (Dianthus caryophyllus L. cv. White Sim) was associated with a 30-fold increase in the concentration of 1-aminocyclopropane-l-carboxylic acid (ACC) in the petals (initial content 0.3 nmol/g fresh weight). Pretreatment of the flowers with silver thiosulfate (STS) retarded flower senescence and prevented the increase in ACC concentration in the petals. An increase in ACC in the remaining flower parts, which appeared to precede the increase in the petals, was only partially prevented by the STS pretreatment. Addition of aminoxyacetic acid (2 raM) to the solution in which the flowers were kept completely inhibited accumulation of ACC in all flower parts.