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1.
Controlling the rate of fruit softening in melting-flesh peaches is a primary goal of the fruit industry. Stony hard (SH) peach varieties lack the ability to synthesize 1-aminocyclopropane-1-carboxylic acid (ACC), the precursor of ethylene, which is required for fruit maturation. SH peaches thus have crisp flesh that remains firm during ripening. In this study, we developed a simple technique to stimulate fruit softening by a single spray application of ACC at a concentration of 10–20 mM, which was sufficient to allow ethylene synthesis and fruit softening. Higher concentrations of ACC increased ethylene production, and made the fruit softer. Ethylene synthesis was limited to the first 2–3 d after ACC treatment, after which fruit ceased softening and retained its remaining firmness. These results indicate that a single application of ACC solution can be used to regulate the process of fruit softening in SH peaches.  相似文献   

2.
The effects of postharvest application of aminoethoxyvinylglycine (AVG) and 1-methylcyclopropene (1-MCP) on ethylene production and fruit quality, and thus on transportation and shelf-life, were evaluated in melting-flesh peaches. AVG (150 mg L−1) significantly reduced ethylene production, and the effect was enhanced in combination with 1-MCP (1 μL L−1). However, fruit treated with AVG alone softened to untreated control levels 2 d after harvest (DAH). Treatment with 1-MCP significantly reduced the rate of softening until 2 DAH, but the fruit rapidly softened thereafter, and reached untreated control levels by 4 DAH. A combination of AVG and 1-MCP significantly reduced fruit tissue softening throughout ripening. The effect of each chemical on flesh firmness indicated that 1-MCP affected fruit response in the early stages of ripening up to 4 DAH, and AVG significantly reduced softening in the latter stages from 4 to 9 DAH. Peaches treated with AVG and 1-MCP retained their ground color during ripening, but the effect of each chemical on color is unclear. The present study indicates that combined treatment with AVG and 1-MCP significantly delays the ripening of melting-flesh peaches.  相似文献   

3.
To investigate the effects of postharvest application of 1-MCP on ethylene production and fruit softening, activities of ethylene biosynthesis and fruit softening enzymes were measured during postharvest ripening of plum (Prunus salicina Lindl. cv. Tegan Blue) fruit after being exposed to 1-MCP (0, 0.5, 1.0 or 2.0 μL L−1) at 20 ± 1 °C for 24 h. Following the treatments, fruit were allowed to ripen at ambient temperature (20 ± 1 °C), and ethylene production in fruit, activities of ACS and ACO, ACC content and fruit softening enzymes (PE, EGase, exo-PG and endo-PG) in fruit skin and pulp were recorded at different intervals. Postharvest application of 1-MCP significantly delayed and suppressed the climacteric ethylene production with reduction in the activities of ethylene biosynthesis enzymes (ACS, ACO) and ACC content, and fruit softening enzymes (PE, EGase, exo-PG and endo-PG) in the skin as well as in pulp tissues. The reduction was more pronounced with increased concentrations of 1-MCP. 1-MCP treated fruit showed different rates of fruit softening and activities of ethylene biosynthesis enzymes in the skin and pulp tissues which warrant further investigation on regulation of gene expression related to these enzymes with the inhibitory effect of 1-MCP.  相似文献   

4.
The effects of postharvest application of aminoethoxyvinylglycine (AVG) and 1-methylcyclopropene (1-MCP) on ethylene production and fruit quality, and thus on transportation and shelf-life, were evaluated in melting-flesh peaches. AVG (150 mg L−1) significantly reduced ethylene production, and the effect was enhanced in combination with 1-MCP (1 μL L−1). However, fruit treated with AVG alone softened to untreated control levels 2 d after harvest (DAH). Treatment with 1-MCP significantly reduced the rate of softening until 2 DAH, but the fruit rapidly softened thereafter, and reached untreated control levels by 4 DAH. A combination of AVG and 1-MCP significantly reduced fruit tissue softening throughout ripening. The effect of each chemical on flesh firmness indicated that 1-MCP affected fruit response in the early stages of ripening up to 4 DAH, and AVG significantly reduced softening in the latter stages from 4 to 9 DAH. Peaches treated with AVG and 1-MCP retained their ground color during ripening, but the effect of each chemical on color is unclear. The present study indicates that combined treatment with AVG and 1-MCP significantly delays the ripening of melting-flesh peaches.  相似文献   

5.
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6.
In this work Aloe vera gel (AV) alone or with the addition of 10 or 2% rosehip oil was used as fruit edible coatings in a wide range of Prunus species and cultivars: peaches (‘Roma’ and ‘B-424-16’ flat type), plums (‘Red Beauty’ and ‘Songria’), nectarine (‘Garofa’) and sweet cherry (‘Brooks’). Following treatments, fruit were stored at 20 °C for 6 days and analysed for the effect of treatments on fruit ripening and quality parameters compared with uncoated fruit (control). The addition of the rosehip oil to AV gel reduced respiration rate in all fruit, and ethylene production in the climacteric ones (peaches, plums and nectarine). In addition, all the parameters related with fruit ripening and quality, such as weight loss, softening, colour change and ripening index, were also delayed in treated compared with control fruit, the effect being generally higher when rosehip oil was added to AV, and especially in those fruit that exhibited the highest ethylene production rates (‘Roma’ and flat type peaches). Although the highest effect was obtained with AV + rosehip oil at 10%, the sensory panel detected an excess of gloss and oiliness on the fruit surface, which was considered as a negative attribute. Thus, 2% rosehip oil added to AV could be used as an innovative postharvest tool to increase the beneficial effect of AV as an edible coating, especially in climacteric fruit showing high ethylene production rates.  相似文献   

7.
The mode of action of nitric oxide (NO) in inhibiting ethylene biosynthesis and fruit softening during ripening and cool storage of mango fruit was investigated. Hard mature green mango (Mangifera indica L. cv. ‘Kensington Pride’) fruit were fumigated with 20 μL L−1 NO for 2 h at 21 °C and allowed to ripen at 21 ± 1 °C for 10 d, or stored at 13 ± 1 °C for 21 d. During ripening and cool storage, ethylene production and respiration rate from whole fruit were determined daily. The 1-aminocyclopropane-1-carboxylic acid (ACC) content, activities of ACC synthase (ACS), ACC oxidase (ACO), and fruit softening enzymes such as pectin esterase (PE), endo-1,4-β-d-glucanase (EGase), exo- and endo-polygalacturonase (exo-PG, endo-PG) as well as firmness and rheological properties of pulp were determined at two- and seven-day intervals during ripening and cool storage, respectively. NO fumigation inhibited ethylene biosynthesis and respiration rate, and maintained higher pulp firmness, springiness, cohesiveness, chewiness, adhesiveness, and stiffness. NO-fumigated fruit during cool storage and ripening had lower ACC contents through inhibiting the activities of both ACS and ACO in the fruit pulp. NO-fumigated fruit showed decreased activities of exo-PG, endo-PG, EGase, but maintained higher PE activity in pulp tissues during ripening and cool storage. In conclusion, NO fumigation inhibited ethylene biosynthesis through inhibition of ACS and ACO activities leading to reduced ACC content in the fruit pulp which consequently, reduced the activities of fruit softening enzymes during ripening and cool storage.  相似文献   

8.
The role of abscisic acid (ABA) in triggering ethylene biosynthesis and ripening of mango fruit was investigated by applying ABA [S-(+)-cis,trans-abscisic acid] and an inhibitor of its biosynthesis [nordihydroguaiaretic acid (NDGA)]. Application of 1 mM ABA accelerated ethylene biosynthesis through promoting the activities of ethylene biosynthesis enzymes (1-aminocyclopropane-1-carboxylic acid synthase, ACS; 1-aminocyclopropane-1-carboxylic acid oxidase, ACO) and accumulation of 1-aminocyclopropane-1-carboxylic acid (ACC), enhanced fruit softening and activity of endo-polygalacturonase and reduced pectin esterase activity in the pulp. The activities of ethylene biosynthesis and softening enzymes were significantly delayed and/or suppressed in the pulp of NDGA-treated fruit. The ABA-treated fruit had higher total sugars and sucrose as well as degradation of total organic acids, and citric and fumaric acids compared with NDGA treatment. These results suggest that ABA is involved in regulating mango fruit ripening and its effects are, at least in part, mediated by changes in ethylene production.  相似文献   

9.
Brown rot caused by Monilinia spp. is the most important postharvest disease of stone fruit. Currently, no chemical fungicides are allowed in the European Union to be applied to stone fruit after harvest. In previous work, radio frequency (RF) treatment for 4.5 min applied with fruit immersed in water at 40 °C was very promising for the control brown rot on peaches and nectarines. In the present study, the efficacy of this radio frequency treatment was studied employing different infection times, inoculum concentrations, fruit maturity levels and in naturally infected fruit. Generally, infection time and maturity level of fruit did not have a significant effect on the RF treatment efficacy and brown rot incidence was significantly reduced in fruit inoculated 0, 24 or 48 h before treatment and at all maturity levels evaluated in both peaches and nectarines. RF treatment significantly reduced brown rot incidence at all inoculum concentrations evaluated (103, 104, 105 and 106 conidia mL−1). However, in peaches, the treatment efficacy was slightly less when the inoculum concentration was increased to 105 or 106 conidia mL−1. In naturally infected fruit, brown rot incidence was significantly reduced from 92% among control fruit to less than 26% in peaches and complete brown rot control was achieved in nectarines. RF treatment did not have an effect on fruit firmness in the varieties tested, and even a delay of fruit softening was observed. Moreover, both external and internal fruit appearance was not affected by the treatment.  相似文献   

10.
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11.
The aim of this work was to study the specific effects of low temperature and 1-MCP treatment on ethylene metabolism and oxidative behaviour in plums (Prunus × salicina cv. Larry Ann). Control fruit were stored at 20 °C or 0 °C and the 1-MCP (625 nL L?1) treated fruit at 0 °C. Changes in the kinetics of ethylene production upon removal were related to changes in ACC metabolism (ACC and MACC levels), oxidative behaviour (H2O2 content) and enzymatic antioxidant potential (SOD, CAT and POX enzymes) during cold storage. Low temperature stress inhibited the synthesis of MACC, which appeared to be the basic process that regulated ACC and ethylene production at ambient temperature. Although 1-MCP treatment inhibited ethylene production and ACC accumulation in the cold, it did not inhibit the accumulation of MACC. Neither cold nor 1-MCP treatment induced oxidative stress. Nevertheless, the 1-MCP treatment significantly impaired the increase in POX activity observed during cold storage. Collectively these results showed the underlying role that ACC metabolism plays in the ripening behaviour of cold-stored plums, confirming previous results. The results also indicate that MACC and malonyl transferase activity are the key regulatory factors that control ripening and possibly some ethylene-related disorders such as chilling injury in cold-stored plums.  相似文献   

12.
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13.
A feature of ‘Honeycrisp’ apples [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] is that they maintain flesh firmness over extended storage. The objective of this study was to elucidate molecular mechanisms that are responsible for slow softening of ‘Honeycrisp’ as compared with a rapidly softening cultivar, ‘McIntosh’. Fruit from both cultivars were picked during the normal harvest period and stored at 20 °C for 10 d. Internal ethylene concentrations (IECs) in ‘Honeycrisp’ fruit were lower than in ‘McIntosh’, but at climacteric levels of ethylene ‘Honeycrisp’ fruit maintained their firmness over this period, while ‘McIntosh’ softened rapidly. Concentrations of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) were higher in ‘Honeycrisp’ than in ‘McIntosh’ apples. qRT-PCR analysis was carried out for genes involved in ethylene biosynthesis, perception and signaling [ACC synthase (MdACS); ACC oxidase (MdACO); ethylene receptors (MdETR and MdERS); constitutive triple response (MdCTR); ethylene response factor (MdERF)], as well as those involved in cell wall metabolism [polygalacturonase (MdPG); xyloglucan endotransglucosylase (MdXTH); expansin (MdEXP); β-galactosidase (Md β-GS); arabinofuranosidase (MdAFase); pectate lyase (MdPL)]. At comparable IECs, the expression of genes involved in ethylene synthesis, ethylene perception and signal transduction was generally much higher in ‘Honeycrisp’ than in ‘McIntosh’ fruit. However, the expression of MdAFase and MdEXP3 was generally lower in ‘Honeycrisp’ than in ‘McIntosh’, while that of MdPG and MdPL was extremely low in ‘Honeycrisp’. Expression of MdPG1 was very low, even though IECs were at climacteric levels. Absence of fruit softening in ‘Honeycrisp’ is probably associated with restricted cell wall enzyme activity. The lower maximum IECs found in ‘Honeycrisp’ compared with ‘McIntosh’ do not appear to be related to expression of genes involved in ethylene biosynthesis.  相似文献   

14.
1-Aminocyclopropane-1-carboxylate (ACC) synthase and oxidase activities, their gene expression, and ethylene production in apple fruit [Malus sylvestris (L.) Mill. Var. domestica (Borkh.) Mansf.] treated with a synthetic auxin 2,4-dichlorophenoxy-propionic acid (2,4-DP) and n-propyl dihydrojasmonate (PDJ), a jasmonic acid derivative, has been investigated to clarify the action of auxin and jasmonates on ethylene production. The fruit was harvested at 103 d after full bloom (preclimacteric). The expression of MdACS4 messenger RNA (mRNA) at 48 and 96 h after treatment was higher in fruit treated with 2,4-DP than in the untreated control, but those of MdACS1 and MdACO1 were not affected by treatment. The ethylene production in 2,4-DP-treated fruit increased at 96 h after treatment. In contrast, expression of mRNAs hybridized with MdACS1 and MdACO1 probes in the skin of PDJ-treated fruit were higher than those in the untreated control. In addition, ACC synthase activity and ethylene production also increased after treatment. These results show that the ethylene production rate may differ with the kind of genes which were stimulated by auxin or jasmonates.  相似文献   

15.
Fruit of cv. Gros Michel banana were treated with 1-MCP (1000 nL L−1 for 4 h at 25 °C) and then packed in non-perforated polyethylene (PE) bags for modified atmosphere storage (MAP). The bags were placed in corrugated cardboard boxes and stored at 14 °C. Fruit were removed from cool storage and ripened at room temperature using ethephon. The length of storage life was determined by the change in peel color to yellow, after this ethephon treatment. Fruit treated with 1-MCP + MAP had a storage life of 100 days. The storage life of control fruit (no 1-MCP and no MAP) was 20 days. Fruit held in PE bags without 1-MCP treatment had a 40 day storage life, and the same was found in fruit treated with 1-MCP but without PE bags. 1-MCP is an inhibitor of ethylene action, but also inhibited ethylene production, mainly through inhibition of ACC oxidase activity in the peel. MAP inhibited ethylene production mainly through inhibition of ACC oxidase, both in the peel and pulp. The combination of 1-MCP treatment and MAP storage resulted in much lower ethylene production due to inhibition of both ACC synthase and ACC oxidase activity.  相似文献   

16.
Monilinia spp. are the most important causes of brown rot in stone fruit and no chemical fungicides are allowed in the European Union to be applied to stone fruit after harvest. From preliminary studies, microwave (MW) treatments at 17.5 kW for 50 s and 10 kW for 95 s were selected as effective conditions to control brown rot. Both treatments were investigated to control Monilinia fructicola in fruit with different weights and maturity levels and in naturally infected fruit. Fruit weight only had a significant effect on microwave efficacy in ‘Placido’ peaches treated by MW at 10 kW for 95 s in which better brown rot control was observed in small than large fruit. Maturity level did not have a significant effect on efficacy of MW treatments in any of the varieties evaluated. When both MW treatments were studied in naturally infected peaches and nectarines, brown rot incidence was significantly reduced to less than 14% compared with untreated fruit where brown rot incidence was higher than 45%. The effect of both treatments on fruit quality was also evaluated. Fruit firmness was not negatively affected in the varieties tested and even a delay of fruit softening was observed. However, internal damage around the stone was observed, especially in the smallest fruit in which high temperature is achieved at the end of both MW treatments.  相似文献   

17.
Tomato fruit were stored in cold rooms at 8 °C containing an adsorbent–catalyst device including activated carbon–1% Pd either alone or with a heater (175 °C) programmed to heat at 3 h pulse intervals. Cold rooms without the adsorbent–catalyst system were used as controls. The use of the device led to very low concentrations of both ethylene and CO2 inside the cold rooms when compared with activated carbon–1% Pd alone or control rooms. In addition, the parameters related to ripening such as respiration rate, ethylene production, 1-aminocylcopropane-1-carboxylic acid (ACC, free and conjugated), colour changes, softening, decrease in total acidity (mainly citric and ascorbic acids) and lycopene were significantly higher in stored tomato fruit in control rooms than in those stored in cold rooms with both adsorbent–catalyst systems. The magnitude of the delay in these parameters was always significantly greater with the use of the device with respect to activated carbon–1% Pd alone. Thus, this device could be considered as a new tool to eliminate the ethylene surrounding fruit and vegetables in storage areas, avoiding the detrimental effects of ethylene action and leading to maintenance of their postharvest quality. Other additional advantages are the auto-regeneration process, when heat pulses were applied to the adsorbent–catalyst system, and the fact that it is an environmentally friendly technology.  相似文献   

18.
The storability of onion bulbs is dependent on the incidence and rate of sprout growth. Exogenous ethylene applied continuously has been demonstrated to act as a sprout suppressant in onion. However, the ethylene binding inhibitor, 1-methylcyclopropene (1-MCP), can also suppress sprouting in onion. Given this seemingly contradictory result, the precise role that ethylene plays during onion storage and the effect of curing on its efficacy is not understood.‘Sherpa’ and ‘Wellington’ onion bulbs were treated before or after curing (28 °C for 6 weeks) with a single dose of 10 μL L−1 ethylene or 1 μL L−1 1-MCP for 24 h at 20 °C, or no treatment (control). Replicated out-turns were sampled during 38 weeks storage at 0–1 °C. Sprout growth (31 weeks after harvest) was reduced in ‘Sherpa’ treated before curing with ethylene or before or after curing with 1-MCP. However, sprout growth of ‘Wellington’ was not affected by any treatment. Following treatment, the cured, thick-skinned ‘Wellington’ released a lower concentration of treatment gas compared with the newly harvested, thin-skinned ‘Sherpa’. Onion bulb respiration rate increased immediately after being treated with ethylene but to a lesser extent or not at all when treated with 1-MCP. Fructose concentrations of onions treated with ethylene or 1-MCP before curing were not significantly different, however, after curing concentrations were about 2-fold higher compared with the control. Mean glucose and sucrose concentrations for both cultivars were higher immediately after being treated before curing with ethylene or 1-MCP than control bulbs. It appears that inhibition of sprout growth can be achieved using just a short 24 h treatment with ethylene or 1-MCP. However, skin thickness or permeability, which is dependent on cultivar and curing, may affect ethylene or 1-MCP influx and therefore efficacy of sprout suppressant action.  相似文献   

19.
Experiments were conducted to examine softening and quality responses of harvested banana fruit to cold shock treatment intended to extend shelf-life. Fruit were immersed in ice-water for 1 h, then treated with or without 100 μL L?1 ethylene for 24 h at 24 °C, and finally stored at 20 °C. Fruit firmness, chlorophyll content, ethylene production, respiration rates, contents of pectin, starch and sugar, and the activities of the cell wall modifying enzymes polygalacturonase (PG), pectin methylesterase (PME) and CMCase (cellulase, endo-1,4-β-glucanase) were analyzed. Total amylase activity was also measured. Immersion in ice-water for 1 h effectively inhibited ripening-associated processes, including peel de-greening and pulp softening during storage or ripening. The delay in ripening was also manifest in reduced ethylene production and respiration rates. The inhibition of softening by cold shock treatment was related to decreased PG and PME activities, that is, retardation of pectin solubilization/degradation. Reduced activities of CMCase and total amylase and conversion of starch to sugar by ice-water immersion also contributed to the delay in softening of harvested banana fruit.  相似文献   

20.
Mangosteen (Garcinia mangostana L.) fruit were harvested when the peel (pericarp) was light greenish yellow with scattered pinkish spots. Fruit were exposed to 1 μL L−1 1-methylcyclopropene (1-MCP) for 6 h at 25 °C and were then stored at 25 °C (control) or 15 °C. The 1-MCP treatment only temporarily delayed softening of the fruit flesh, during storage. Storage life, defined as the time until the pericarp was dark purple, was much longer in fruit stored at 15 °C than in fruit stored at 25 °C. It was also longer in 1-MCP treated fruit (storage life at 15 °C: control 18 d, 1-MCP-treated fruit 27 d). The 1-MCP treatment also increased the length of shelf life, defined as the time until the pericarp turned blackish purple or showed calyx wilting, at 25 °C. 1-MCP treatment reduced ethylene production. It also reduced pericarp levels of 1-aminocyclopropane-1-carboxylic acid (ACC), and the pericarp activities of ACC synthase (ACS) and ACC oxidase (ACO). In the fruit flesh, in contrast, 1-MCP did not affect ACC levels and ACS activity, but the treatment reduced ACO activity. Taken together, both the storage life and the shelf life of the fruit were extended by the 1-MCP treatment. A decrease in ACO activity largely accounted for the effects of the 1-MCP on ethylene production in the pericarp.  相似文献   

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