Application Of 1-MCP Research Articles

Effect of Postharvest Application of 1-Methycyclopropene on Storage Behavior of Fresh Tomatoes (S olanum lycopersicum L.)

The present study was conducted on fresh tomatoes (cv. Punjab Ratta) of mature green to breaker stage treated with 1-methycyclopropene (1-MCP) at different concentrations to find out its efficacy on storage behavior at 13 ± 2C and relative humidity (RH) of 85–90%. Data from this study suggested that 1-MCP had no effect on the TSS content of the fruits during the period of storage. Fruits treated with 1-MCP at 180 mg/10 L recorded the lowest physiological loss in weight throughout the storage period compared to control. At 26 days after treatment, fruits treated with 1-MCP at 120 mg/10 L recorded the significant lowest decay (9.87%) over control (35.65%). Studies on titratable acidity (TA) revealed that fruits treated with 1-MCP at 180 mg/10 L recorded a higher TA up to 11 days after storage and at 1-MCP at 120 mg/10 L maintained higher TSS from 16 to 21 days after treatment. Practical Applications Considering the postharvest behavior of tomato being a climacteric fruit, it is essential to control the ethylene production to maintain the fruit quality during storage. 1-methylcyclopropene is a potent inhibitor of ethylene action and has been used for extending the shelf life and maintaining the quality of fresh products. Aqueous application of 1-MCP is easy, quick and effective method to extend the shelf life and preserve the quality of tomatoes compared to gaseous application.

Effects of 1-methylcyclopropene on postharvest quality of white- and yellow-flesh loquat (Eriobotrya japonicaLindl.) fruit

Introduction. The effects of 1-methylcyclopropene (1-MCP) were evaluated on white-flesh cv. Claudia and yellow-flesh cv. Nespolone di Trabia loquat fruit. Materials and methods. Application of 1-MCP ((0.5 to 1) µL⋅L -1 for 20 h)) was monitored at 20 °C (7 days) and 0 °C (7 days at 0 °C and then 7 days at 20 °C). Results. Treatments with 1-MCP slowed fruit softening, depending on the concentration. Softening inhibition was greatest in fruit treated and held at 20 °C. The optimum concentration for softening inhibition at 20 °C was 1µ L ⋅L -1 of 1-MCP, while 0.5 µL⋅L -1 of 1-MCP was more effective at 0 °C. Conclusion. Treatments with 1-MCP inhibited titratable acidity loss in both cultivars. 1-MCP extends the shelf life of rapidly softening, perishable fruits such as loquat fruit. Italy / Eriobotrya japonica / fruits / postharvest losses / postharvest physiology / keeping quality

Effects of elevated CO2 and 1-methylcyclopropene on storage-related disorders of Ontario-grown Empire apples

Deyman, K. L., Chiu, G., Liu, J., Brikis, C. J., Trobacher, C. P., DeEll, J. R., Shelp, B. J. and Bozzo, G. G. 2014. Effects of elevated CO2 and 1-methylcyclopropene on storage-related disorders of Ontario-grown Empire apples. Can. J. Plant Sci. 94: 857–865. The impact of 1-methylcyclopropene (1-MCP) application on CO2-induced physiological injury in Empire apple fruit during controlled atmosphere storage was assessed over a 3-yr period using an experimental design involving multiple treatment replicates. Fruit harvested at optimal maturity from one or two orchards were treated with or without 1 µL L−1 1-MCP, then chilled at 0 or 3°C under various CO2 partial pressures (5, 2.5 or 0.03 kPa CO2) in the presence of 2.5 kPa O2 for up to 46 wk using a split-plot design. Fruit were sampled periodically for assessment of flesh browning and external peel injury. The maximal incidence of external CO2 injury varied from 15 to 100% over the 3 yr, and the most rapid development of this disorder was evident at 5 kPa CO2. The incidence of external CO2 injury as a function of storage time was influenced by orchard location and storage temperature. Moreover, the incidence of flesh browning at 0°C and 5 kPa CO2 was influenced slightly by orchard; this disorder was never higher than 30%, and the impact of elevated CO2 was inconsistent across years. Notably, there was no evidence for negative effects of 1-MCP on the incidence of storage-related disorders.

<b>Influence of waxing coupled to 1-methylcyclopropene on compositional changes in early harvested ‘gold’ pineapple for export

This work evaluated the changes in quality in early-harvested ‘Gold’ pineapple after coating with wax and exposure to 1-Methylcycloprepene before or after coating. The storage conditions and the experimental period simulated those of shipping and marketing, assuming that Ceará,Brazil, is the production site andEuropeis the marketplace. Evaluation was performed after harvest, upon removal of the fruit from cold storage, and every three days during room storage. Evaluations included visual quality of the fruit, shell yellowing, mass loss, flesh color, soluble solids, titratable acidity, pH, soluble solids to acid ratio, ascorbic acid, total soluble sugars, reducing sugar, phenolic content, and yellow flavonoids. Low temperature was the key variable for maintaining fruit quality during storage and simulated shipping. Waxing had a remarkable effect on visual quality, delaying yellowing and reducing shell dehydration. Those effects were not enhanced by the application of 1-MCP. 1-MCP treatment resulted in the maintenance of total phenolic content and retention of yellow flavonoids. Fruit flesh became lighter, while yellow color became more vivid during storage. Sugars and pH varied little during storage, while the decline in TA was more intense in waxed fruit. 1-MCP and waxing may be combined to preserve external and internal quality.

Effects of elevated CO2 and 1-methylcyclopropene on storage-related disorders of Ontario-grown Empire apples

Deyman, K. L., Chiu, G., Liu, J., Brikis, C. J., Trobacher, C. P., DeEll, J. R., Shelp, B. J. and Bozzo, G. G. 2014. Effects of elevated CO2 and 1-methylcyclopropene on storage-related disorders of Ontario-grown Empire apples. Can. J. Plant Sci. 94: 857-865. The impact of 1-methylcyclopropene (1-MCP) application on CO2-induced physiological injury in Empire apple fruit during controlled atmosphere storage was assessed over a 3-yr period using an experimental design involving multiple treatment replicates. Fruit harvested at optimal maturity from one or two orchards were treated with or without 1 µL L-1 1-MCP, then chilled at 0 or 3°C under various CO2 partial pressures (5, 2.5 or 0.03 kPa CO2) in the presence of 2.5 kPa O2 for up to 46 wk using a split-plot design. Fruit were sampled periodically for assessment of flesh browning and external peel injury. The maximal incidence of external CO2 injury varied from 15 to 100% over the 3 yr, and the most rapid development of this disorder was evident at 5 kPa C...

Ethylene as a Postharvest “Evil” and its Remedies in some Horticultural Crops

Postharvest is an agricultural operation starting from the time of harvesting till the commodity reaches to the ultimate user/consumer. The postharvest life of horticultural produces is different from other produces in having shortest shelf life. In some horticultural crops which we call climacteric, there is an increase rate of respiration mainly due to a very high synthesis of the ripening hormone (ethylene), which has both beneficial and detrimental (“evil”) effects depending on the type of commodity. The effect of ethylene is accumulative so continuous exposure to a low concentration of ethylene throughout marketing can cause significant harm. In climacteric fruits exogenous C2H4 caused the peel and flesh to ripen out of phase, with the flesh ripening faster than the peel. In a study of cut flowers, exposure to ethylene at 100 μl l-1 reduced vase life by about 30%. In order to minimize this evil effect different vase solutions have been investigated. STS (silver thiosulfate) and 1-MCP (1-methylcyclopropene) can effectively protect flowers against exogenous ethylene. Pre-treatment of plants with 1 μl l-1 1- MCP for 2 h completely inhibited ethylene-induced petal abscission. Applications of Silver thiosulphate (STS) and 1-MCP have a great role to withstand the impact of ethylene. Thus they give relief for those concerned with horticultural crops which are sensitive to ethylene action. However more researches have to be done about the level and time of application of these chemicals and a new chemical against ethylene should be investigated.

Simultaneous application of ethylene and 1-MCP affects banana ripening features during storage

In order to avoid the ripening blocking effect of 1-MCP (1-methylcyclopropene) on bananas when applied before ethylene commercial treatment, 1-MCP in combination with 'CD ethylene' (ethylene-cyclodextrin complex) was used in gas formulations: 300 nmol mol(-1) 1-MCP + 1200, 2400 or 4800 nmol mol(-1) ethylene (ETH). Control bananas received 1-MCP alone or 4800 nmol mol(-1) ethylene alone or no treatment. Treatments were done on overseas shipped bananas, at 14 °C, 90% relative humidity (RH), for 16 h; the bananas were stored under the same atmospheric conditions. After 4 or 12 days the bananas were commercially treated with 500 µmol mol(-1) ethylene. A 300 nmol mol(-1) 1-MCP treatment significantly blocked banana ripening in terms of physiological and technological parameters, inhibiting ethylene production and respiration, despite the commercial ethylene treatment. The application of 300 nmol mol(-1) 1-MCP + 1200 or 2400 nmol mol(-1) ethylene delayed ripening but with a regular pattern. A 300 nmol mol(-1) 1-MCP + 4800 nmol mol(-1) ethylene application did not delay ripening as did 4800 nmol mol(-1) ethylene treatment. The development of black spots was closely associated with advanced ripening/senescence of fruits. The combined 300 nmol mol(-1) 1-MCP + 1200 or 2400 nmol mol(-1) ethylene treatment appears to be a promising treatment to extend banana storage, following overseas shipping.

Effects of 1‐Methylcyclopropene and Hot Water Quarantine Treatment on Quality of “Keitt” Mangos

The optimal 1-methylcyclopropene (1-MCP) treatment to slow ripening of whole "Keitt" mangos, either alone or in combination with hot water treatment (HWT) (prior to or post 1-MCP) was identified. USDA-APHIS mandates that HWT can be used for control of fruit flies, but this may affect fruit response to 1-MCP. Mangos were evaluated by repeated measurement of nondestructive firmness, peel color, and ethylene production on the same mango fruits during 2 wk of ripening at 20 °C after treatment. The magnitude of ethylene production increased as a result of both 1-MCP and HWT. With softer mangos (65 N), treatment with 1-MCP alone delayed fruit softening and extended the number of days to full-ripeness (25 N) from 5 d in untreated fruit to 11 d. For these riper fruit, application of 1-MCP prior to HWT extended the days to full-ripeness to 9 d compared with 7 d when 1-MCP was applied after HWT. With firmer mangos (80 N), 1-MCP treatments alone prolonged the days to full-ripeness to 13 d as compared to 11 d for the untreated fruit. There was no significant concentration effect on firmness retention among 1-MCP treatments (0.5, 1.0, or 10.0 μL/L). HWT resulted in a faster rate of fruit softening, taking only 7 d to reach full-ripeness. Combining 1-MCP with HWT reduced the rate of softening compared to HWT alone, resulting in 9 to 11 d to full-ripeness. Application of 1-MCP before HWT showed a greater ability to reduce the rate of fruit softening compared with 1-MCP treatment after HWT.

Ethylene Biosynthetic Responses of Mango (Mangifera indica L. cv. ‘Carabao’) Fruits to 1-methylcyclopropene (1-MCP) Preharvest Aqueous Spray Applications

800x600 The ethylene antagonist 1-methylcyclopropene (1-MCP) was used as a tool to investigate the mechanism of ethylene feedback regulation in mango (Mangifera indica L. cv. ‘Carabao’) fruits. The ethylene biosynthetic responses of mango fruits to 1-MCP applied prior the upsurge in ethylene production on-tree which was around 100 days after flower induction (DAFI) were studied. Aqueous 1-MCP spray formulation with 10 ppm concentration was applied to on-tree mango fruits at 100 DAFI. From these sprayed fruits, four (4) sets of fruits were tagged for a second round of 10 ppm aqueous 1-MCP spraying. One set was sprayed the second time at 105 DAFI, while the remaining sets at 110, 115 and 120 DAFI respectively. The positive control was sprayed with 0 ppm 1-MCP while the negative controls were the unsprayed fruits. Representative fruit samples from each set were harvested 2 d after spraying and every 2 d thereafter until reaching 120 DAFI. Right after each harvest, samples were analyzed for internal ethylene, ethylene production, ACC levels and ACC oxidase activities. The negative control exhibited two internal ethylene peaks before harvest maturity. However, in 1-MCP treated fruits, low levels of ethylene were detected and the second peak was not observed. A single application of 1-MCP at 100 DAFI resulted in lower ethylene production compared with controls. However, a second application proved to be more effective as the lowering of ethylene production was carried over until the day of harvest. The levels of 1-aminocyclopropane-1-carboxylate (ACC) increased after 110 DAFI for the controls. Reapplication of 1-MCP at 110 DAFI resulted to lower ACC levels, which was not observed with the other treatments with 1-MCP reapplication. Possibly, new ethylene receptors are synthesized at 110 DAFI, and 1-MCP reapplication at this time effectively blocks ethylene binding to the new receptors. ACC oxidase activity was lowered by 1-MCP applied at 100 DAFI compared with the controls. However, trends in ACC oxidase activities were almost the same for all the treatments and controls after 105 DAFI. Thus, ACC oxidase proceeds with its normal activity without being inhibited by 1-MCP. This suggests that ethylene biosynthesis in ‘Carabao’ mango fruit is regulated at the level of ACC synthase and not ACC oxidase. Thus, autocatalytic ethylene biosynthesis in ‘Carabao’ mango can be controlled by regulating ACC synthase activity, which proves that ACC synthesis is the rate limiting step in ethylene feedback mechanism in ‘Carabao’ mango. Normal 0 false false false EN-PH X-NONE X-NONE

Aplicação do 1-metilciclopropeno e sua influência no processo de remoção da adstringência com etanol em caqui 'Giombo' refrigerado

Este trabalho tem como objetivo verificar a possibilidade de aplicação de vapor de etanol para a destanização, associado ao 1-metilciclopropeno (1-MCP) para prolongar o armazenamento de caquis 'Giombo' em ambiente refrigerado, evitando rápido amolecimento de polpa, decorrente do processo de destanização. Os seguintes tratamentos foram realizados: T1) controle: frutos sem tratamento, apenas colocados sob armazenamento refrigerado (AR); T2) aplicação de etanol (3,50mL kg-1 durante 12h) + AR; T3) aplicação de 1-MCP (1000nL L-1 durante 12h) + AR; T4) aplicação de 1-MCP e posterior aplicação de etanol + AR; T5) aplicação de 1-MCP + AR + aplicação de etanol após o AR. O AR consistiu no armazenamento dos frutos por 30 dias a 5ºC e 90% UR. Posteriormente, os frutos foram mantidos a 25oC durante 15 dias. Frutos não tratados (controle) e os tratados com 1-MCP apresentaram maior firmeza de polpa que os demais tratamentos, mas não alcançaram a destanização. Frutos submetidos ao etanol apresentaram rápida perda de adstringência, acompanhado de elevada perda de firmeza. O 1-MCP, quando aplicado antes do armazenamento, em frutos que posteriormente à refrigeração foram tratados com etanol, manteve mais alta a firmeza de polpa em relação aos frutos que foram submetidos ao etanol imediatamente à aplicação do 1-MCP e aqueles tratados apenas com etanol. Esse tratamento pode ser utilizado nessa cultivar para manter a qualidade durante a comercialização.

Ripening delay caused by 1-MCP may increase tomato chilling sensitivity

The export of New Zealand tomatoes is restricted to Australia and Pacific Island nations and constrained by the cost and shortage of airfreight space. The industry does not have a consistent commercial solution to enable sea freight to the Asian market. A potent inhibitor of ethylene response, 1-methylcyclopropene (1-MCP) has emerged as a tool for controlling ripening and extending the shelf life of many fresh products. Knowledge of 1-MCP effects on cool-stored fresh tomatoes is limited. In the present study, mature-green and breaker tomatoes treated with 1-MCP were stored at 2.5 °C for 5 weeks. At this temperature, 1-MCP treatment enhanced Alternaria decay severity (from latent infections) and resulted in softer fruit than non-treated controls, whereas 1-MCP reduced decay from ‘ripe rots’ when fruit were ripened at 20 °C. These results suggest that the ripening delay induced by 1-MCP may increase tomato chilling sensitivity during cool storage. While 1-MCP shows promising results in extending postharvest storage life in many crops, including tomatoes, these results indicated that application of 1-MCP before cool storage is not appropriate for assisting commercial sea freight of tomatoes. Nonetheless, it may be possible to apply 1-MCP and then store tomatoes above the temperatures that cause chilling injury in order to extend storage life.

Ethylene and 1-MCP affect the postharvest behavior of yellow pitahaya fruits (Selenicereus megalanthus Haw.)

The pitahaya or dragon fruit is one of the most representative exotic fruits that Colombia has, with an important, growing international market, but the cultivation and postharvest of this fruit lack sufficient technological support to be more competitive. Therefore, alternatives that provide good-quality products that meet market requirements are very important. Therefore, the objective of this research was to determine the effect of a ripening retardant and ethylene application on the conservation and quality of pitahaya fruits and the possible changes during ripening associated with ethylene, for which a completely randomized design with three treatments was used, corresponding to the application of ethylene (ethephon, 3 mL L-1), 1-methylcyclopropene (1-MCP, 600 mg L-1) and a control, with four replications, for a total of 12 experimental units. The fruits were stored at 18°C with 75% relative humidity. The 1-MCP application significantly decreased the loss of firmness, total soluble solids, loss of fresh mass and respiratory rate. Fruits from the control and ethylene treatment tended toward a climateric respiratory behavior. The total carotenoid content of the fruits was significantly higher in the ethylene application and the control treatment, which was consistent with the color change of the fruits. It can be concluded that the 1-MCP application reduced the ethylene action, slowing the ripening of the dragon fruits.

Involvement of 1-Methylcyclopropene in Plant Growth, Ethylene Production, and Synthase Activity of Inferior Spikelets in Hybrid Rice Differing in Panicle Architectures

Chlorophyll content (SPAD values) of leaves, 1-aminocyclopropane-1-carboxylic acid synthase (ACS) activities and ethylene production of inferior spikelets, aboveground biomass, grain yield, and yield components were studied to compare the effects of 1-methylcyclopropene (1-MCP) on plant growth, and inferior spikelet development in hybrid rice (Oryza sativa L.) differing in panicle architectures. There were four hybrid rice cultivars in this trial, including two lax-panicled cultivars, Liangyoupeijiu (LYPJ) and Guodao 6 (GD6), and two compact-panicled cultivars, Yongyou 9 (YY9) and Yongyou 12 (YY12). Results showed that chlorophyll content of leaves in 1-MCP treatment was higher than control (CK) after application of 1-MCP. ACS activities and ethylene production in 1-MCP treatment for LYPJ, GD6, and YY9 were significantly decreased compared to their corresponding CK. Aboveground biomass and grain yield of cultivars were increased with the increase of chlorophyll content of leaves, but decreased with the increase of ACS activities and ethylene production of inferior spikelets. On average, grain yield in 1-MCP treatment for LYPJ was increased by 7.3 % compared to CK, GD6 was increased by 2.6 %, YY9 was increased by 3.2 %, and YY12 was increased by 0.8 %, respectively. Application of 1-MCP showed marked effects on increasing spikelet fertility and harvest index of cultivars, but exhibited little effects on improving sink capacity and 1,000-grain weight. Our results indicate that 1-MCP could play a positive role in regulating the growth and development of hybrid rice with lax panicles or with compact panicles.

Controle da maturação de caqui 'Fuyu' com aplicação de aminoetoxivinilglicina e 1-metilciclopropeno

O armazenamento de caquis é uma ferramenta importante na manutenção da qualidade e no prolongamento da oferta do fruto após a colheita. O objetivo deste trabalho foi avaliar o efeito da aplicação de AVG em pré-colheita, e do 1-MCP, em pré e pós-armazenamento, sobre a manutenção da qualidade pós-colheita e seu efeito na incidência de distúrbios em caquis 'Fuyu' armazenados em atmosfera controlada a -0,5 ºC e transferidos a condição de ambiente (20 ºC) por 6 dias. Os tratamentos foram: [1] controle; [2] aplicação de AVG (123 g ha-1); [3] aplicação de 1-MCP (1,0 µL L-1) em pré-armazenamento; [4] aplicação de AVG e 1-MCP em pré-armazenamento; [5] aplicação de 1-MCP em pós-armazenamento; [6] aplicação de AVG e 1-MCP em pós-armazenamento. Os frutos foram avaliados quanto à qualidade na ocasião da colheita, visando à caracterização do lote e, após quatro meses de armazenamento a -0,5 ºC e mais seis dias a 20 ºC, quanto à firmeza da polpa, pH, coloração da casca, índices de amaciamento e de escurecimento, teores de sólidos solúveis e de acidez titulável, respiração, produção de etileno, além da atividade da enzima ACC oxidase. Os resultados indicaram que a aplicação de 1-MCP em pré ou em pós-armazenamento foi eficiente em conter o amaciamento da polpa de caquis 'Fuyu' previamente armazenados em atmosfera controlada a -0,5 ºC e mantidos a 20 ºC por seis dias. Todavia, o uso deste fitorregulador em pré-armazenamento ocasionou maior escurecimento da epiderme. O uso de AVG em pré-colheita não retardou a maturação de caquis 'Fuyu' armazenados na mesma condição.

Condições de atmosfera controlada para armazenamento de ameixas "Laetitia' tratadas com 1-metilciclopropeno

O objetivo deste trabalho foi avaliar o efeito de condições de atmosfera controlada (AC), combinadas ou não com a aplicação de 1-MCP, sobre o amadurecimento e a manutenção da qualidade de ameixas "Laetitia', especialmente sobre a incidência de degenerescência da polpa. Os tratamentos avaliados foram: T1 - 21 kPa de O2 + <0,05 kPa de CO2; T2 - 1 kPa de O2 + 1 kPa de CO2; T3 - 1 kPa de O2 + 1 kPa de CO2, com 1-MCP (1 µL L-1); T4 - 2 kPa de O2 + 3 kPa de CO2; T5 - 2 kPa de O2 + 3 kPa de CO2 com 1-MCP (1 µL L-1). Após 60 dias de armazenamento (0,5 ± 0,1 ºC e 96 ± 2% de UR) e mais três dias em condição ambiente (20 ± 2 ºC e 60 ± 5% de UR), os frutos foram avaliados quanto aos atributos de índice de cor vermelha (ICV), cor da polpa e epiderme, firmeza de polpa, atributos de textura, acidez titulável, taxas respiratória e de produção de etileno e incidência de degenerescência de polpa. Também foi realizada análise sensorial dos frutos com painel não-treinado. O armazenamento nas duas condições de AC (1 kPa de O2 + 1 kPa de CO2 e 2 kPa de O2 + 3 kPa de CO2) retardou o amadurecimento de ameixas "Laetitia', porém não inibiu a incidência de degenerescência da polpa. Contudo, a condição de AC 1 kPa O2 + 1 kPa CO2, associada ao tratamento com 1-MCP, reduziu a intensidade do escurecimento da polpa e conferiu maior aceitabilidade dos frutos.

The Role of Ethylene and Calcium in Programmed Cell Death of Cold-Stored Cucumber Fruit

Programmed cell death (PCD) occurs during plant development and in response to various stimuli, including biotic and abiotic stresses. Characteristics of PCD were detected in cucumber fruit after 9 days of cold storage at 2C, including chromatin condensation and DNA fragmentation. PCD development was accompanied by ethylene emission and cytosolic free calcium ([Ca2+]cyt) release. The role of ethylene production and [Ca2+]cyt in chill-induced PCD were studied through the application of 1-methylcyclopropene (1-MCP; an ethylene perception inhibitor) and ethylene glycol bis (2-aminoethyl) tetraacetic acid (EGTA; a divalent cation chelator). Results indicated that hallmarks of PCD were identified in cucumber fruit suffering from chilling stress and diagnostic events of PCD were alleviated and/or delayed by 1-MCP or EGTA applications. Therefore, ethylene and calcium could play significant roles in the initiation and execution progress of cold-induced PCD. Practical Applications Cucumber fruit is chilling sensitive at temperatures below 10C. It has also been showed that exogenous ethylene could induce PCD features in cucumber fruits and [Ca2+]cyt plays a key role in regulating apoptosis. However, information about roles of endogenous ethylene and calcium in the PCD process of cucumber under cold stress has been rarely reported. The data in this study provided a theoretical basis for understanding the mechanism of chilling injury in cucumber fruit and benefited exploration of strategies to prevent it.

1-MCP nos aspectos fisiológicos e na qualidade pós-colheita de maçãs Eva durante o armazenamento refrigerado

O objetivo deste estudo foi verificar o efeito de doses específicas do composto 1-metilciclopropeno (1-MCP), após a colheita, nos aspectos fisiológicos e na qualidade físico-química de maçãs Eva durante o armazenamento refrigerado. Após a aplicação dos tratamentos com diferentes doses de 1-MCP (0, 10, 50, 100 e 500mg L-1), os frutos foram armazenados em câmara fria 0,5°C (±0,5) por até 135 dias. O armazenamento refrigerado juntamente com a aplicação de 1-MCP resultou em uma menor produção de etileno, principalmente nos frutos tratados com as doses de 10, 50 e 100mg L-1. O grupo controle perdeu 45% de sua firmeza, enquanto os grupos tratados perderam, em média, 27% de sua firmeza. O parâmetro C de cor identificou frutos com cor mais intensa aos 135 dias de armazenamento e o ângulo Hue mostrou que, quando tratados com as doses de 10 e 50mg L-1, os frutos apresentaram-se mais amarelados, evidenciando melhor ação do 1-MCP em baixas concentrações. Frutos que não foram submetidos aos tratamentos apresentaram maior relação sólidos solúveis e acidez, demonstrando assim maior atividade metabólica.

Morphological and molecular characterization of ethylene binding inhibition in carnations

Ethylene perception by ethylene receptors can be suppressed by ethylene antagonists, such as 1-methylcyclopropene (1-MCP). 1-MCP binds to ethylene receptors blocking ethylene binding, and thereby represses ethylene responses, including flower senescence and petal abscission. Despite its antagonistic propensity, plants treated with 1-MCP often regain sensitivity to ethylene, suggesting that ethylene receptors are synthesized de novo post-treatment. To investigate this observation, we determined the relationship between the mRNA levels of ethylene biosynthesis and ethylene receptor genes and the degree of ethylene sensitivity of carnation flowers after ethylene and 1-MCP treatments. Flowers treated with a single application of 1-MCP lost the inhibitory effect in ethylene production after 7d of the treatment. In contrast, multiple treatments with 1-MCP completely suppressed several ethylene biosynthesis genes and ethylene production throughout the experiment. Multiple 1-MCP treatments increased vase life by almost three-fold relative to control flowers. Eventually ethylene-independent browning and desiccation on the edges of petals contributed to loss of vase life. We observed that the transcript levels of the ethylene receptor genes, DcETR1 and DcERS1, decreased with flower development, but increased at the onset of floral senescence. Our results suggest that ethylene receptors are continually synthesized during later stages of floral development. While ethylene responsiveness is temporarily blocked by 1-MCP treatment, we predict that new receptors synthesized days after 1-MCP treatment can bind ethylene. This leads to the observed recovery of ethylene sensitivity in the flowers. In addition, we predict that the degradation of ethylene receptors that is stimulated by ethylene binding is prevented by successive treatments with 1-MCP prior to recovery of ethylene sensitivity. This study improves our understanding about the uses and effectiveness of 1-MCP and will facilitate the development and improvement of postharvest treatments for multiple crops.

The harvest period of mangosteen fruit can be extended by chemical control of ripening—A proof of concept study

Mangosteen is an economically important crop in Southeast Asia. However, the harvest period of mangosteen fruit is rather short and effective methods to expand the harvest period and lessen the peak workload are desirable. We investigated the preharvest applications of ethephon or 1-methylcyclopropene (1-MCP) for their effects on harvest date, ethylene production, and mangosteen fruit quality. 1-MCP is available as tablets that we applied on fruit as a sprayed solution as well as by fumigation, respectively.The ripening of mangosteen fruit was significantly affected by the treatments, so that harvest date was advanced to an earlier time with ethephon and delayed to a later time by 1-MCP when using color development to guide harvest (at stage 0, pericarp uniformly yellowish-white or with a light green tinge or grayish spotting). The induced changes of harvest time are each of the order one to two weeks. The effectiveness of these chemicals is associated with the maturity stage of intact fruit. The increase period of ethylene production occurs concomitantly with unchanged fruit weight at its stationary phase of development. However, the ethylene production of harvested fruit was not affected by the treatments. The preharvest application of ethephon or 1-MCP, at climacteric maturity of fruit, has potential use in altering the harvest period of mangosteen products to earlier or later dates.

플럼코트 '하모니' 과실의 수확 후 품질에 미치는 저장온도 및 1-MCP 처리의 영향

본 실험은 자두와 살구의 종간잡종인 플럼코트 '하모니' 과실의 수확 후 적정저장 온도를 구명하고 에틸렌작용 억제제인 1-MCP 처리효과를 알아보기 위하여 수행되었다. 과실은 숙기를 3가지로 구분하여 수확 후 각각 0, 5, 10 및 <TEX>$20^{\circ}C$</TEX>의 온도에 저장하였고, 1-MCP(<TEX>$1{\mu}L{\cdot}L^{-1}$</TEX>) 처리는 <TEX>$10^{\circ}C$</TEX>에서 24시간 처리 후 <TEX>$10^{\circ}C$</TEX>에 저장하였다. 온도가 낮은 저장조건일수록 플럼코트 '하모니' 과실의 호흡량을 현저히 낮추었고 온도가 높을수록 호흡량의 증가와 함께 품질이 빨리 저하되었다. 저장온도 <TEX>$20^{\circ}C$</TEX>는 과실의 부패가 빠르게 촉진되어 유통조건으로 부적합하였다. 숙기에 따른 품질은 30-50% 정도의 붉은 착색 과실이 양호하였는데 특히, <TEX>$10^{\circ}C$</TEX>에 저장할 때, 식미가 가장 양호하였다. 1-MCP는 플럼코트 '하모니' 과실의 연화, 색도 변화, 산도 변화 등 전체적인 품질의 변화를 지연시키는데 효과적이었다. This study was conducted to investigate the optimum storage temperature and the effect of 1-methylcyclopropene (1-MCP) on the postharvest physiology and quality of plumcot (Prunus salicina Lindle. <TEX>${\times}$</TEX> Prunus armeniaca L.) 'Harmony' fruits. plumcot fruits were stored at 0, 5, 10, and <TEX>$20^{\circ}C$</TEX>, respectively, with three different ripeness stages grouped by skin color development. Furthermore, we treated <TEX>$1{\mu}L{\cdot}L^{-1}$</TEX> 1-MCP was treated at <TEX>$10^{\circ}C$</TEX> for 17 hours and stored at <TEX>$10^{\circ}C$</TEX> for 12 days to evaluate the effectiveness for better shelf-life. The results indicated that lower storage temperature than room temperature effectively reduced the respiration rate with delaying quality changes. While, the fruits showed worse fruit taste than the fruits stored at 10 and <TEX>$20^{\circ}C$</TEX>. Reversely, the fruits stored at <TEX>$20^{\circ}C$</TEX> showed more respiration rate and ethylene production. 1-MCP treatment effectively reduced the skin red color development, ethylene production, <TEX>$CO_2$</TEX> and softening of plumcot 'Harmony' fruits. Overall data indicated that the optimum harvest time and storage temperature could be 30-50% red color and near <TEX>$10^{\circ}C$</TEX>. Postharvest 1-MCP application at the level of <TEX>$1.0{\mu}L{\cdot}L^{-1}$</TEX> could maintain fruit quality well in plumcot fruits.