Internal Ethylene Concentration Research Articles

Differential Effects of Ethephon and Seniphos on Color Development of `Starking Delicious' Apple

The differential effects of two color improving products, ethephon an ethylene-releasing compound, and seniphos, a nonethylene-releasing product, were studied on `Starking Delicious' apples (Malus domestica Borkh L.). Ethephon and seniphos were applied 2 or 3 weeks before commercial harvest. Ethephon- and seniphos-treated fruit showed a significant improvement of peel color associated with a sharp increase in anthocyanin content and chromaticity values. Color improvement in ethephon-treated apples occurred during the preharvest period and cold storage. The seniphos-treated fruit stopped color development in cold conditions. In comparison to the ethephon-treated fruit, the seniphos-treated apples showed lower internal ethylene concentrations and a ripening delay. Both treatments sharply increased the activity of phenylalanine-ammonia-lyase enzyme, which seemed to be the determining factor of color enhancement. The seniphos-treated apples compared to ethephon had higher fruit firmness and lower soluble solids concentrations. Anthocyanin biosynthesis may be enhanced by seniphos treatment without inducing ethylene production or other ripening associated changes. As a consequence, fruit treated with seniphos can be held longer in storage.

Maturation and storage quality of six ‘Golden Delicious’ × ‘Red Dougherty’ apple selections

Abstract The maturation and storage quality of six ‘Golden Delicious’ x ‘Red Dougherty’ apple (Malus domestica Borkh.) selections (3561, 4354, 4396, 4766, 4772, and 5029) were investigated for one season. Three selections (4396, 4354, and 4772) were studied for a further season. Selections matured at different rates and the timing of increased internal ethylene concentrations and starch pattern indices varied between selections. Fruit of Selection 4772 from all harvests developed severe internal browning in storage. Selections 5029, 4772, 4354, and 4396 were susceptible to superficial scald but except for Selection 4772 incidence of the disorder declined with progressive harvest date. Appropriate harvest periods will need to be based on market criteria and consumer acceptability.

Do tomatoes on the plant behave as climacteric fruits?

I considered the possibility that changes in fruit photosynthesis obscure the occurrence of the climacteric rise in respiration in tomato fruits attached to the plant. Internal CO2 and ethylene concentrations in tomatoes (Lycopersicon esculentum Mill. cv. OH 7814) were analyzed after direct sampling through polyethylene tubes implanted in the external pericarp. Fruits which were shaded with aluminium foil contained up to 60 ml 1−1 CO2, until the internal ethylene concentration exceeded 1 μl l−1, when CO2 concentration declined to below 40 ml l−1; the CO2 concentration in fruits exposed to light only occasionally exceeded 40 ml 1−1. The internal CO2 concentration of detached fruits first declined and then increased along with ethylene concentration, as expected for the climacteric. Detached green fruits under continuous low photosynthetic photon flux density (100 μmol m−2 s−1) contained almost no internal CO2 and produced no CO2. Changes in photosynthesis and an associated CO2‐generating system in green fruits are thought to obscure the climacteric rise in tomato fruits developing on the plant.

リンゴ‘つがる’の後期落果および貯蔵中の果実品質に及ぼすアミノエトキシビニルグリシン（ＡＶＧ）ならびに２，４‐ＤＰの影響

The effects of aminoethoxyvinylglycine (AVG) and 2, 4-dichlorophenoxy-propionic acid (2, 4-DP) applications to apple cv. Tsugaru on 1) preharvest drop, 2) internal ethylene concentration, 3) 1-aminocyclopropane-1-carboxylic acid (ACC) content, 4) ACC oxidase activity, 5) abscisic acid (ABA) content and 6) fruit quality during storage at 1 °C were investigated.1. Foliar applications of 90 or 180 ppm AVG were made on whole trees 96 or 109 days after full bloom (DAFB) ; a 45 ppm 2, 4-DP spray was applied 96 DAFB. Although the preharvest drop of the untreated control amounted to 32.1%, it was only 1.3% and 1.96.7%with 2, 4-DP and AVG applications, respectively.2. Internal ethylene concentration and ACC content in the peel and pulp of fruits were higher with 2, 4-DP treatment, but were lower with AVG treatment compared to the untreated control. The 2, 4-DP-treated and untreated control apples had the highest internal ethylene concentration after 60 days in storage, while the ethylene concentration of AVG-treated fruits increased gradually during 120 days in storage. The ACC content in 2, 4-DP-treated and untreated control apples increased dramatically after 20 days in storage, and then sharply decreased to its initial level. On the other hand, that with AVG application, ACC level increased slightly. ACC oxidase activity with each treatment showed a continuous increase from after 20 days in storage. These results may indicate that ACC oxidase activity besides ACC content is related to the rate of ethylene production from fruits during storage at 1 °C. ABA content in the pulp of 2, 4-DP-treated and untreated control apples increased rapidly after 20 days in storage and then fell continuously. Thus, ABA content in the pulp did not show a pattern similar to the increase in the internal ethylene concentration but rather to that of the ACC trend.3. Foliar applications of AVG not only reduced preharvest drop, but they also delayed the loss of chlorophyll in the peel and the softening of the fruit during storage, i. e., fruit senescence.

Effect of flower and fruit thinning on the maturity of ‘Cox’s Orange Pippin’ apples at harvest

Summary‘Cox’ apple trees were hand thinned to one flower or fruit per cluster at 5, 27 and 39 d after full-bloom (FB) and the rate of maturation of fruit on the tree was assessed by removing apple samples at weekly intervals before, during and after the anticipated commercial harvest date, and measuring internal ethylene concentration (IEC), firmness, soluble solids (SS) and starch content (starch iodine test). Respiratory behaviour and ethylene production by fruits removed from the trees and held at 12°C was also monitored. Background colour was measured on fruit at the final sampling date. Earlier maturation of fruits from trees thinned at FB + 5 d was indicated by increased IEC and respiration rate, and a shorter delay to ethylene production. These characteristics were not affected significantly by thinning at 27d or 39 d after FB. Although rate of starch and firmness decline and increase in SS are commonly used for predicting harvest date, these criteria are unsuitable to measure the effects of thinning on fruit maturation, since fruits from thinned trees are firmer and higher in SS than those from unthinned trees. The estimated maturity advance caused by early thinning varied according to the assessment criteria used with a maximum advance of 16 d suggested by IEC. Firmness improvement by thinning was reduced progressively with harvest delay and fruit from all thinning treatments were less green and more yellow than those from unthinned trees at the final harvest.

316 ROOTSTOCK AFFECTS RIPENING OF `MCINTOSH' APPLES

`Summerland Red McIntosh' apple trees propagated on M.9/A.2,O.3, M.7 EMLA, M.26 EMLA, M.7A. OAR1, or Mark rootstocks were planted in 1985 in a randomized complete block design with seven replications. Fruit ripening and quality were assessed in 1988-93. Internal ethylene concentrations were measured weekly throughout each harvest season. Once each season, fruit weight, starch-index value, soluble solids concentration, flesh firmness, and surface ted color were assessed on a sample of fruit from each tree. Size was smallest for fruit from trees on OAR1 or Mark, after accounting for the effects of crop load with analysis of covariance. Surface ted color was greatest for fruit from trees on Mark and least for fruit from trees on M.7 EMLA. Ripening was variable, but generally, fruit from trees on 0.3 ripened first, and fruit from trees on M.7 EMLA or M.7A ripened last. Crop load impacted ripening, but its effects were removed with analysis of covariance.

The effect of humidity on ripening of durians

Abstract Weight loss of ‘Chanee’ durians ripening under humidities of 75 to 93% was between about 2.6 and 3.8% day−1. Low humidity caused an increase in internal ethylene concentration and in the ease of dehusking but did not hasten ripening. Water stress had no significant effect on starch content, soluble solids, total sugars, firmness and colour development of the pulp of ripened durians. Results are discussed in relation to advantages and disadvantages of ripening durians under low and high humidities.

Submergence-Induced Ethylene Synthesis, Entrapment, and Growth in Two Plant Species with Contrasting Flooding Resistances.

Submergence-induced ethylene synthesis and entrapment were studied in two contrasting Rumex species, one flood-resistant (Rumex palustris) and the other flood-sensitive (Rumex acetosa). The application of a photoacoustic method to determine internal ethylene concentrations in submerged plants is discussed. A comparison with an older technique (vacuum extraction) is described. For the first time ethylene production before, during, and after submergence and the endogenous concentration during submergence were continuously measured on a single intact plant without physical perturbation. Both Rumex species were characterized by enhanced ethylene concentrations in the shoot after 24 h of submergence. This was not related to enhanced synthesis but to continued production and physical entrapment. In R. palustris, high endogenous ethylene levels correlated with enhanced petiole and lamina elongation. No dramatic change in leaf growth rate was observed in submerged R. acetosa shoots. After desubmergence both species showed an increase in ethylene production, the response being more pronounced in R. palustris. This increase was linked to the enhanced postsubmergence growth rate of leaves of R. palustris. Due to the very rapid escape of ethylene out of desubmerged plants to the atmosphere (90% disappeared within 1 min), substantial underestimation of internal ethylene concentrations can be expected using more conventional vacuum extraction techniques.

Response of apples to diazocyclopentadiene inhibition of ethylene binding

Diazocyclopentadiene (DACP) is a light-activated compound that is thought to inhibit ethylene binding in plants. DACP was applied as a gas in the light for 24 hours to ‘Red Delicious’ apples harvested at a mature, preclimacteric stage. Treated apples held in air at 21°C for 30 days had lower internal ethylene concentrations than untreated fruits. Higher concentrations of DACP were more effective over longer periods of time. Untreated apples had a flesh firmness of 46 newtons after 30 days, while DACP treated apples were about 73 newtons. Starch conversion initially was slowed by DACP, but by 30 days all starch was lost. Retreatment of fruit with DACP during the 30 days did somewhat renew the effect on suppression of ethylene, but did not further effect flesh firmness or starch conversion. Apples treated once with DACP at harvest, then held in 0°C cold storage, contained much lower levels of internal ethylene and were approximately 10 newtons firmer after 18 weeks than untreated fruit.

Fruit maturity and quality of selectively picked ‘Royal Gala’ apples

Abstract Royal Gala' apple trees were selectively picked to export grade criteria on either two or four occasions during the commercial harvest period, and the maturity and quality of fruit compared at harvest and after storage. When the total crop was recovered using four sequential picks, overall maturity at harvest was less advanced and less variable, and fruit were firmer, greener, and less greasy after storage than when the crop was harvested using only two selective picks. The most uniform fruit quality was obtained from the second and third picks of trees harvested four times. Internal ethylene concentrations tended to increase within commercial background colour categories with progressively later harvest date. Total fruit yield and size distribution was similar for the overall crop from both harvest regimes. These results indicate that four rather than two harvests, and segregation of packed lines according to time of harvest, may be used to optimise out‐turn quality of ‘Royal Gala’ apples.

SOURCES OF VARIATION IN FRUIT QUALITY OF `BRAEBURN' APPLE AT HARVEST AND AFTER STORAGE.

Export-packed fruit of `Braeburn' apple ware collected on three dates corresponding to the early, mid and late periods of commercial harvest. Fruit were segregated into categories determined by background color, combined with percent fruit surface area with red blush of <40%, 40-70% and >70%. A separate category comprised fruit which showed marginal sunburn discolouration. Fruit were assessed at harvest and after 16 weeks air storage at O°C. Quality and maturity indices which were affected by harvest date included starch pattern index, flesh firmness and soluble solids concentration (SSC). However differences due to harvest data were not evident after storage. Fruit with more yellow background color or marginal sunburn were distinguished by advanced starch hydrolysis, higher internal ethylene concentration and higher SSC at harvest. After storage these fruit had yellowest background color, softer flesh and highest SSC. Fruit with green-yellow background color and >70% blush showed similar but less pronounced trends. Organoleptic assessment after storage showed a higher frequency of inferior texture and juiciness associated with categories of fruit with indices indicating advanced maturity at harvest and following storage.

Regulated Deficit Irrigation May Alter Apple Maturity, Quality, and Storage Life

`Delicious' apple (Malus domestica Borkh.) trees received regulated deficit irrigation (RDI) early in the growing season to determine if fruit quality and storage life would he altered compared to well-watered trees. Soil moisture and leaf water potential were lower in RDI trees than in those that did not receive RDI most of the season. Internal ethylene concentration increased logarithmically earlier in RDI apples. At harvest, RDI fruit were smaller and had a higher soluble solids concentration (SSC) and lower titratable acidity. Starch degradation was delayed in RDI fruit, and their color was not affected. Firmness was not affected when the effect of size on firmness was removed. The SSC of RDI apples remained higher during storage, but starch content, titratable acidity, firmness, and color were similar.

収穫後におけるキウイフルーツのエチレン生成と果実軟腐病の関係について

1.5°Cで1~5か月貯蔵後のキウイフルーツを20°Cに出庫し, 軟腐病果由来のエチレンが健全個体のエチレン生成に及ぼす影響と, このエチレンに影響されない, キウイフルーツ本来のエチレン生成の開始時期を知ろうとした.2.軟腐病個体が生じるエチレンの影響を考慮せず,キウイフルーツを出荷用ダンボール箱に貯蔵した場合には, 出庫後比較的早い時期にエチレン生成が認められた果実はすべて軟腐病果で, 健全果ではこれより遅れて, エチレン生成が始まった.3.出庫後のキウイフルーツをポリエチレンフィルムで個装したり, 硬質ポリ塩化ビニル樹脂容器内にエチレン吸着剤とともに入れ, 24時間間隔で容器内の空気の交換を行う条件でエチレンの蓄積を防いだ場合には, エチレン生成が認められたのは軟腐病果に限られ, 健全な個体では20°Cに出庫後, 40~60日経過後もエチレン生成はほとんど認められなかった.4.3.の条件下での炭酸ガスの蓄積, 酸素の減少はわずかで, CA効果で健全果のエチレン生成を抑制し得るほどの濃度ではなかった.5.健全果の1-アミノシクロプロパン-1-カルボン酸含量, エチレン生成酵素活性, 果実内エチレン濃度は出庫42日後でも, いずれも低レベルのままであった.6.以上の結果から, キウイフルーツは軟腐病に罹病したり, その果実由来のエチレンの影響がない限り,エチレン生成は起こらないと判断した.

‘Hosui’ fruit (Pyrus serafina) grown in New Zealand is nonclimacteric

Abstract Changes of fresh weight, flesh firmness, soluble solids, skin colour, respiration rate, internal ethylene concentration, and ethylene production were assessed for Japanese pear (Pyrus serotina cv. Hosui) fruits during maturation. Fruit fresh weight, soluble solids contents, and skin colour grade increased, firmness and respiration rates decreased with maturation, but internal ethylene and ethylene production remained undetectable. Ripening characteristics of ‘Hosui’ were investigated by measuring the respiration rate and ethylene production of fruit treated with propylene during maturation. Fruit respiration rate was enhanced in the presence of 0.5% propylene and declined upon removal of the gas. Ethylene production was not enhanced by exposure of fruit to propylene and remained at undetectable levels through the experiment. The results suggest that ‘Hosui’ fruit grown in New Zealand is nonclimacteric.

AN EVALUATION OF BENZYLADENINE AS A POSSIBLE CHEMICAL THINNER OF “EMPIRE”

Field trials at Cambridge Research Station, Ontario, Canada, studied the thinning effect of benzyladenine (BA) on eighteen-year-old “Empire” apple trees. At 16 days after full bloom (fruit diameter 12.87 mm) whole trees were hand sprayed to drip point with BA (0, 100, or 200 mg.1-1). Untreated control trees were compared with treated and hand thinned trees. BA significantly reduced crop load on “Empire”. The thinning response to BA was linear, with recommended thinning occurring at 200 mg.1-1. At harvest, fruit weight, size (diameter and length), flesh firmness and soluble solids concentration, chlorophyll and anthocyanin contents, and seed number were increased by BA treatments. BA had no effect on fruit L:D ratio, internal ethylene concentration, maturity, and the onset of the respiratory climacteric, but significantly reduced respiration at harvest. BA also reduced ethylene production and ACC content at harvest, though the reduction was not significant. Although firmness of BA-treated fruit was significantly higher at harvest, upon storage for 1 month at 0-0.5°C and 90-95% RH the firmness advantage was lost BA shows potential as a thinner of “Empire” apple and has advantage of increasing fruit weight and size, since “Empire” is a relatively small apple compared to other commercial cultivars.

MATURATION AND STORAGE OF FUJI APPLES (Malus domestica Borkh)

Several strains of Fuji apples were harvested weekly from September through October in 1990 and 1991, and evaluated for maturation and quality after 1 and 7 days at 20 °C following harvest and storage in atmospheres of 0.5%, 1.0%, 2.0% O2 and air. Results showed that Fuji apples have very low ethylene production rates and little firmness loss during maturation. A change in the postharvest respiration pattern preceded the increase ethylene synthesis. Oxygen concentration during storage directly affected apple respiration rate after removal from storage. Ethylene production rates and internal ethylene concentrations indicated that the apples were still in the preclimacteric stage after 7 to 9 months storage at 0.5%, 1.0%, or 2% O2. Fuji apples develop watercore and tend to have a particular type of corebrowing during maturation on the tree, or during and after storage. The cause is unknown.

Maturity and ripening effects on chemical and sensory properties of apple juice

AbstractThe effects of harvest maturity and ripening on the chemical composition and sensory characteristics of ‘McIntosh’ and ‘Spartan’ apple juice were evaluated. Juice was extracted from fruit harvested at seven weekly intervals beginning 3–4 weeks before commercial harvest and from fruit held in air storage (1°C) for 1 to 3 months. Internal ethylene concentration and starch index were used as maturity indices. Principal component analysis of juice data (pH. titratable acidity, organic acids, soluble solids, sugars, phenols, turbidity, and Hunterlab colour) showed a distinctive maturity effect on the characteristics of juice extracted from fruit immediately after harvest or after storage. Triangle testing showed aroma and flavour differences in both ‘McIntosh’ and ‘Spartan’ to be first discernable when ethylene was first detected (internal ethylene concentration ≥ 0.1 μl litre−1) and starch hydrolysis evident (starch index 3.0–5.0 for ‘McIntosh’, 1.5–3.0 for ‘Spartan’), or after 2–3 months of air storage. Sensory profiling of fruity aroma, total aroma, fruit flavour by mouth, sweetness, and sourness in the juices showed increased fruitiness and sweetness and decreased sourness with advancing maturity.

The effects of collar rot(Phytophthora cactorum) on ‘Cox’s Orange Pippin’ fruit quality

The effects of collar rot (Phytophthora cactorum) of ‘Cox’s Orange Pippin’ apple trees on fruit maturity and quality at harvest and after storage have been investigated. Fruit were harvested from trees in five orchards in Nelson, New Zealand. Trees were either without signs of collar rot (control), or were girdled by collar rot lesions, but all were producing fruit which might be commercially harvested. At harvest, fruit from diseased trees had higher starch pattern indices, flesh firmness, soluble solids content, percentage blush, lower titratable acidity levels, and were more yellow than control fruit. Internal ethylene concentrations of fruit were at preclimacteric levels at harvest and were not influenced by collar rot. Magnesium and potassium concentrations were lower in fruit from diseased than from control trees, but calcium concentrations were not different. After storage, fruit from diseased trees were slightly firmer than fruit from control trees but there was no effect of collar rot on backgrou...

Relationships between mineral content, lipoxygenase activity, levels of 1-aminocyclopropane-1-carboxylic acid and ethylene emission in apple fruit flesh disks (cv. Jonagold) during storage

Abstract Lipoxygenase activity (LOX), levels of 1-aminocyclopropane-1-carboxylic acid (ACC) and of 1-malonyl-aminocyclopropane-1-carboxylic acid (MACC) and the capacity of isolated fruit disks to evolve ethylene were examined during storage of apples having different fruit mineral content. The internal ethylene concentration (IEC) of the whole fruit was also measured before removing discs of tissue. The results show that all these activities depend on the fruit mineral content and confirm general knowledge on the relations between minerals and fruit storage. For instance, fruits rich in calcium and/or phosphorus presented a lower LOX activity, a lower ACC content and a lower ethylene emission while fruits rich in potassium and/or with a relatively high K/Ca presented a higher LOX activity, a higher ACC level and a higher ethylene emission. Results are discussed in an attempt to explain the effects of minerals on storage quality.

Galactose metabolism and ethylene production during development and ripening of tomato fruit

During tomato fruit growth, a steady decline in cell wall galactosyl residues was accompanied by an increase in soluble galactose and occurred in both ‘Rutgers’ and non-ripening mutant rin fruit. However, after maturation and a cessation in the net decrease in galactosyl residues between the mature green and breaker stages of ripeness, ‘Rutgers’ fruit exhibited an abrupt, ripening-related decrease in cell wall galactosyl residues and increase in soluble galactose; rin fruit did not. The net decrease in pericarp cell wall galactosyl residue content occurred significantly before an increase in internal ethylene concentration, however, the increase in soluble galactose did not. Mutant rin fruit showed a constant rate of galactosyl residue loss throughout ontogeny and no increase in soluble galactose occurred. Galactokinase, UDP-galactose pyrophosphorylase, and UDP-galactose-4′-epimerase activities were detected in tomato fruit throughout development and senescence. However, no significant difference in the activities of the three enzymes was found between ‘Rutgers’ and rin fruit. Results show that the decrease in galactosyl content occurs separate from the increase in ethylene evolution and that the resulting increase in monomeric galactose is most likely due to an increase in the rate of galactosyl solubilization from the cell wall, rather than from a decrease in ability to metabolize solubilized galactose.