Large‐scale virulence tests using trees or saplings are expensive, time‐consuming and require a considerable amount of space. The suitability of using ‘Golden Delicious’ apples as a rapid screen for ...identifying Ophiostoma novo‐ulmi transformants with reduced virulence was thus evaluated. When a collection of O. novo‐ulmi field isolates belonging to subspecies novo‐ulmi or americana was inoculated to apples, members of subsp. novo‐ulmi induced, on average, larger necrotic lesions than subsp. americana isolates. The size of the lesions on apples was not correlated with mycelial growth rate of isolates on nutrient agar. Insertional mutants from O. novo‐ulmi subsp. novo‐ulmi isolate H327 were inoculated to ‘Golden Delicious’ apples and Ulmus parvifolia × U. americana saplings in parallel experiments. Results clearly indicated that the O. novo‐ulmi transformants included several exhibiting significantly altered levels of virulence. Variability among replicates within a treatment was reduced in apple inoculation data compared to elm sapling data. Overall, the ‘Golden Delicious’ apple assay was found to be an excellent means for rapidly assessing the virulence level of O. novo‐ulmi isolates.
A novel edible coating for apple fruits Behnam Jahanshahi; Azam Jafari; Mohammad Reza Vazifeshenas ...
Journal of horticulture and postharvest research Online,
03/2018, Letnik:
1, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Edible coatings are an environmentally friendly technology that is applied to many products to control moisture transfer, soluble and aromatic materials, gas exchange or oxidation processes. The ...objective of this research was to study the effect of tragacanth gum at the concentrations of 0, 5, 10, and 15 kg m-3 on storage life and edible quality of apple cvs. Red Delicious and Golden Delicious. After applying treatments, the fruits were kept in a cold storage at a temperature of 0±1 ˚C and relative humidity of 85-95 percent. The weight reduction, external quality, microbial load, and general acceptability of the samples were evaluated after 0, 30, 60, 90 and 120 days of storage, then compared with uncoated apples. It was found that the tragacanth gum significantly reduced fruit weight loss compared to the control, so that weight reduction in uncoated apples was eight times greater than fruits treated with tragacanth gum at 10 kg m-3. This coating preserved firmness of fruit tissue in storage and prevented the softening and senescent breakdown of apples. The tragacanth gum coating desirably preserved the external quality and improved the microbial load, sensory and external properties of the fruits, preserved quality factors of the apples, and prevented fruit ripening during storage. Among the various treatments, the coating at 10 kg m-3 was more effective than the other treatments, maintained fruit juice acidity and pH at desirable levels, and prevented increases in the contents of soluble solids during the storage.
The purpose of this research was to determine the residue analysis of difenoconazole in apple fruits from Resen region, Republic of Macedonia. Analyzed were two varieties of apples, Golden Delicious ...and Idared. Samples were taken from two different locations in Resen in the year 2016. Difenoconazole analysis was performed with liquid chromatography-tandem mass spectrometry (LC-MS/MS) after a previous extraction of residue by applying the QuEChERS method. The obtained concentrations of residues of difenoconazole are compared with the maximum residue limit regulated by the Macedonian legislation. Analyses showed that the concentration of difenoconazole in both varieties of apples from two different locations is in the range of 0.01 to 0.41 mg/kg. In certain development phase of the apple fruits the concentration reaches 80 times lower concentration than the maximum limit. The data show that apple fruits can be safely consumed according to the recommended maximum residue limit (MRL) for difenoconazole in apples (0.8 mg/kg). Statistical processing of the data suggests that there is no significant difference between samples but presence of difenoconazole in apple fruits from both locations is with significant difference.
In developing countries, food losses occur mainly during the production, harvest, postharvest and processing phases. Because of the lack of awareness in the apple postharvest practices in Lebanon, ...this study was carried out to check the effect of good harvesting and handling practices, pre-storage sorting, and dipping in calcium and fungicide, on the percent losses of Golden Delicious apples during six months of cold storage. A highly significant reduction in the percent of total damages was observed during storage when good harvesting and handling practices and pre-storage sorting were applied. The magnitude of losses reduction depended on the type of damage registered and the practices performed. The presence of injuries was reduced by all types of good practices, applied alone or in combination. Where good harvesting and handling practices were performed, the incidence of bruising was reduced from 93.3% in the non-treated control to 37.7% and symptoms of rot were not detected. This study emphasized the importance of good harvest and postharvest practices in improving and maintaining the quality of Lebanese apples.
Display omitted
•The abscission process and the levels of selected metabolites were monitored.•Fruitlets from lowest positions were most likely to shed.•Fruits from the position nearest to the king ...fruitlet often dropped, too.•Central and lateral fruitlets differ to a certain degree in the contents of metabolites.•Phenolic contents are higher in fruitlets more susceptible to abscission.
The abscission process and the modifications in the levels of selected metabolites were monitored on ‘Golden Delicious’ apples in a two-year study. Individual sugars were analyzed using HPLC-RI and individual phenolics by UHPLC–PDA–MS. Fruitlets from lowest positions were most likely to shed. Moreover, fruits from the position nearest to the king fruitlet often dropped. The experiment initially focused on the comparison of sugar and phenolic contents among fruitlets within individual apple clusters. Central (king) fruitlets are bigger in comparison to lateral fruitlets and differ to a certain degree in the contents of metabolites. In general, the results indicate that phenolic contents are higher in fruitlets more susceptible to abscission but the level of sugars does not differ.
The levels and distribution of 9 trace elements in apples from two orchards in north-east (NE) Romania were measured by means of Atomic Absorption Spectroscopy (AAS) on 42 samples of 9 different ...apple varieties, with average content ranges of 0.909-4.458 mg·kg
Zn, 0.055-0.409 mg·kg
Cu, 0.700-2.476 mg·kg
Fe, 0.328-0.695 mg·kg
Mn, 0.054-0.257 mg·kg
Ni, 0.005-0.101 mg·kg
Cr, 0.027-0.420 mg·kg
Co, 0.413-1.149 mg·kg
Pb, and 0.025-0.127 mg·kg
Cd. For some apple varieties, Pb contents are 2 times higher than the maximum contents allowed according to national standards, Cd contents are 6 times higher, and in some cases Zn contents also exceed the national threshold, showing preferential accumulation on specific apple varieties. Whilst some research has been carried out on trace element distribution in apples, this study assessed the areal distribution of toxic trace elements in connection to the adjacent roads. The first apple orchard is located near a county road, with reduced car traffic, while the second orchard shares its southern limit with a high-volume traffic road (E583). The results point towards a proportional increase of Pb and, to some extent, of Cd in the samples close to the E583 road in contrast with the other orchard, where no such observation derived. Along the areal distribution of the selected elements, the preferential accumulation of dietary recommended trace elements in different apple varieties was assessed. In matters of daily nutrients content in trace elements, the best sources of Fe, Cu, and Zn in terms of apple varieties are Golden Delicious, Jonathan, and Kaltherer Böhmer.
This work aims to estimate the shelf life of Golden Delicious apple fruit stored at room temperature by determining the changing trend in color every week using a non-destructive measurement method. ...Moreover, the study will measure the changes in weight loss (Δm) and the total soluble solids (TSS) contained in the apple. The research focuses on the last stage of ripening and the effect of shelf life affecting consumer behavior; therefore, the examined fruits were picked at the end of the season and were stored at an ambient temperature and in controlled laboratory conditions for six weeks, at 24 °C under 60% RH relative. Color measurements were performed with a portable color sensor, which provided a simple and effective examination method in the case of an appropriate number of fruit samples. The findings showed a significant increase in TSS and weight loss over time. Color varying (ΔE) and chroma (C*) parameters increased with prolonged storage duration, meaning that the color of the apples became darker and more color-saturated at the end of storage. While weight loss and TSS follow a linear tendency in the given storage period, the color changes in deteriorating fruits were characterized by exponential asymptotic regression. It was found that although the moisture content reaches its limit value during the drying process of apples, the saturation of color coordinates allows for determination of the limit parameters of consumption in the linear stage of weight loss. The saturation limits (70.97; 12.77; 56.34 CIELAB L*; a*; b*), the dominant color part (b*), and the growth rate of the saturation curves allow an accurate characterization of ripening from the visual aspect, thus determining the limit parameters of shelf life and improving the critical analysis factors affecting the life of fruits after harvest. By assessing color characteristics using a non-destructive technology, customers may quickly evaluate the quality of apples and make better decisions during their purchase.
Chemical thinning of apple fruitlets is an important practice as it reduces the natural fruit load and, therefore, increases the size of the final fruit for commercial markets. In apples, one ...chemical thinner used is Metamitron, which is sold as the commercial product Brevis
(Adama, Ashdod, Israel). This thinner inhibits the electron transfer between Photosystem II and Quinone-b within light reactions of photosynthesis. In this study, we investigated the responses of two apple cultivars-Golden Delicious and Top Red-and photosynthetic light reactions after administration of Brevis
. The analysis revealed that the presence of the inhibitor affects both cultivars' energetic status. The kinetics of the photoprotective mechanism's sub-processes are attenuated in both cultivars, but this seems more severe in the Top Red cultivar. State transitions of the antenna and Photosystem II repair cycle are decreased substantially when the Metamitron concentration is above 0.6% in the Top Red cultivar but not in the Golden Delicious cultivar. These attenuations result from a biased absorbed energy distribution between photochemistry and photoprotection pathways in the two cultivars. We suggest that Metamitron inadvertently interacts with photoprotective mechanism-related enzymes in chloroplasts of apple tree leaves. Specifically, we hypothesize that it may interact with the kinases responsible for the induction of state transitions and the Photosystem II repair cycle.
Codling moth (CM), Cydia pomonella (L.) (Lepidoptera: Tortricidae) is a major fruit feeding pest of apples. Understanding susceptibility differences of various apple cultivars to CM oviposition is an ...important step in developing resistant varieties as well as monitoring and management strategies for this pest in apple orchards planted with mixed-cultivars. In this context, oviposition preferences of CM for the fruits of different apple cultivars were studied in laboratory bioassays using a series of no-choice and multiple-choice tests in 2006, 2007, and 2008. In 2006 and 2007, 10 apple cultivars, viz., Arlet, Fuji, Gala, Golden Delicious, Honeycrisp, Pristine, Delicious, Stayman, Sunrise, and York Imperial were evaluated, while in the 2008 tests, Golden Delicious, Honeycrisp, and York Imperial were evaluated. During the 2006 tests, preferred apple cultivars for CM oviposition were Golden Delicious and Fuji, while the least preferred were Arlet, Pristine, Sunrise, and Honeycrisp. Similarly, during the 2007 tests, Golden Delicious, Fuji and Stayman remained the preferred cultivars, while Arlet, Honeycrisp, Pristine, and Sunrise remained the least preferred cultivars. In the 2008 tests, Golden Delicious and Honeycrisp were the most and least preferred cultivars, respectively. Based on the oviposition preferences from these bioassays, a susceptibility index for each cultivar was developed. This index may be used as a standard measure in cultivar evaluations in breeding programs, and may assist fruit growers and crop consultants to select the most appropriate cultivar(s) for monitoring and detecting the initial signs of fruit injury from CM in an apple orchard planted with mixed-cultivars.
Cyclic voltammetry of apple fruits: Memristors in vivo Volkov, Alexander G.; Nyasani, Eunice K.; Tuckett, Clayton ...
Bioelectrochemistry (Amsterdam, Netherlands),
December 2016, 2016-Dec, 2016-12-00, 20161201, Letnik:
112
Journal Article
Recenzirano
A memristor is a resistor with memory that exhibits a pinched hysteretic relationship in cyclic voltammetry. Recently, we have found memristors in the electrical circuitry of plants and seeds. There ...are no publications in literature about the possible existence of memristors and electrical differentiators in fruits. Here we found that the electrostimulation of Golden Delicious or Arkansas Black apple fruits by bipolar periodic waves induces hysteresis loops with pinched points in cyclic voltammograms at low frequencies between 0.1MHz and 1MHz. At high frequencies of 1kHz, the pinched hysteresis loop transforms to a non-pinched hysteresis loop instead of a single line I=V/R for ideal memristors because the amplitude of electrical current depends on capacitance of a fruit's tissue and electrodes, frequency and direction of scanning. Electrostimulation of electrical circuits in apple fruits by periodic voltage waves also induces electrotonic potential propagation due to cell-to-cell electrical coupling with electrical differentiators. A differentiator is an electrical circuit in which the output of the circuit is approximately directly proportional to the rate of change of the input. The information gained from electrostimulation can be used to elucidate and to observe electrochemical and electrophysiological properties of electrical circuits in fruits.
Display omitted
•Electrostimulation by bipolar voltage waves induces electrotonic potentials in apples.•Electrical networks in apple fruits have electrical differentiators.•Apple fruits have memristors, resistors with memory.•TEACl, an inhibitor of K+ channels, transforms memristors to resistors in apples.
PDF
