Browsing by Author "Terry, Leon A"
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Item Open Access 1-Methylcyclopropene (1-MCP) effects on natural disease resistance in stored sweetpotato(Wiley, 2018-03-06) Amoah, Robert S.; Terry, Leon ABACKGROUND The potential of 1-methylcyclopropene (1-MCP) to maintain postharvest storage of sweetpotato was studied. In two separate experiments, the orange-fleshed sweetpotato cv. Covington was fumigated with 1-MCP (1.0 μL L-1, 24 h) and roots stored at 15 oC. During storage, samples were evaluated for the respiration rate, sprout growth, weight loss, incidence of decay and changes in dry matter. The roots were further assayed for the temporal changes in individual non-structural carbohydrates and phenolic compounds in the skin and flesh tissues of the proximal (stem end), middle, and distal (root end) regions. RESULTS 1-MCP treatment reduced root weight loss and decay but respiration rate and non-structural carbohydrates were not affected. No sprouting was recorded irrespective of the treatment. 1-MCP transiently suppressed the accumulation of individual phenolic compounds, especially in the middle and distal segments. This accentuated the proximal dominance of phenolic compounds. Isochlorogenic acid A and chlorogenic acid were the dominant phenolics in the skin and flesh tissues, respectively. CONCLUSION 1-MCP treatment may have anti-decay effect and reduce weight loss. Therefore, storage trials which involve the use of continuous ethylene supplementation to inhibit sprout growth may be combined with 1-MCP to alleviate ethylene-induced weight loss and decay in sweetpotato.Item Open Access 1-Methylcyclopropene maintains postharvest quality in Norwegian apple fruit(Sage, 2019-12-26) Falagán Sama, Natalia; Terry, Leon ANorwegian fruit production is mostly destined for the local market and can suffer from poor-quality retention during storage. 1-Methylcyclopropene (1-MCP) is an inhibitor of ethylene perception used to maintain the physical and functional quality of pome fruit. Extensive work has been carried out on the effect of 1-MCP on apples, but not on cultivars grown in Norway. In this work, the potential of 1-MCP application (0.625 ml l −1 for 24 h at 0 ± 1℃) for ripening control of the apple cultivars ‘Aroma’, ‘Red Gravenstein’, and ‘Summered’ was studied during 1 and 1.5 months of cold storage; both scenarios were followed by five days of shelf life. The application of 1-MCP reduced softening by an average of 12% in ‘Aroma’, ‘Red Gravenstein’, and ‘Summered’ apples when cold stored for both 1 and 1.5 months as compared to control. External colour remained similar to initial values in 1-MCP fruit when compared to control apples, which presented a significant skin darkening. This indicated a delay in the ripening process. 1-MCP treatment did not affect total soluble solids content. ‘Aroma’ samples treated with 1-MCP showed a low sucrose hydrolysis, indicating a slower ripening process. This work confirms that 1-MCP postharvest treatment shows great potential for maintenance of apple cvs. in Norway during cold storage and shelf life.Item Open Access Assuring potato tuber quality during storage: A future perspective(Frontiers Media, 2017-11-28) Alamar, M Carmen; Tosetti, Roberta; Landahl, Sandra; Bermejo, Antonio; Terry, Leon APotatoes represent an important staple food crop across the planet. Yet, to maintain tuber quality and extend availability, there is a necessity to store tubers for long periods often using industrial-scale facilities. In this context, preserving potato quality is pivotal for the seed, fresh and processing sectors. The industry has always innovated and invested in improved post-harvest storage. However, the pace of technological change has and will continue to increase. For instance, more stringent legislation and changing consumer attitudes have driven renewed interest in creating alternative or complementary post-harvest treatments to traditional chemically reliant sprout suppression and disease control. Herein, the current knowledge on biochemical factors governing dormancy, the use of chlorpropham (CIPC) as well as existing and chemical alternatives, and the effects of pre- and post-harvest factors to assure potato tuber quality is reviewed. Additionally, the role of genomics as a future approach to potato quality improvement is discussed. Critically, and through a more industry targeted research, a better mechanistic understanding of how the pre-harvest environment influences tuber quality and the factors which govern dormancy transition should lead to a paradigm shift in how sustainable storage can be achieved.Item Open Access Avocado firmness monitoring with values obtained by means of laser doppler vibrometry(International Society for Horticultural Science, 2012-04-01) Terry, Leon A; Landahl, SandraAvocado (Persea americana Mill.) ripeness is usually evaluated by destructive firmness assessment, yet quality is notorious for being heterogeneous within a consignment. This problem, which is especially true for imported avocado fruit, lends itself to searching for non-destructive methods for firmness evaluation. Firmness of objects can be analysed by impulse-response. This technique utilizes recording of a vibration signature and interpretation of the resonant frequency. In this study a laser Doppler vibrometer (LDV) was used for non-contact recording. The aim of this study was to show the feasibility of using a LDV to monitor avocado firmness. In order to create avocado batches of different homogeneity, three groups were treated with and without ethylene, inside or outside a box. After day 0 a third of the fruit were transferred into boxes (325 L) to be treated with ethylene for 24 h. A third was kept in boxes untreated and another third was kept on open trays. Avocado fruit cultivar ‘Hass’ were ripened at 18°C and measured on days 0, 2, 3, 4 and 6. Individual fruit were impacted once and two LDV measurements were taken simultaneously at the stem-end and seed-end. This was repeated twice around the fruit. Force-deformation measurements in compression mode were performed by means of uniaxial testing (Instron model 5542) on two opposite sides (day 0 n=8, then n=24 i.e., 8 per treatment/d). Significant differences were found between firmness of avocados over time and across treatments. Firmness decreased exponentially as expected (304.1 to 2.1 N) over six days. The LDV results showed significant differences between days, treatments and laser-location. The resonant frequency of the fruit decreased linearly until day 4 and then decreased more slowly (1671 to 476 Hz). On average, the frequency found at the seed-end of the fruit was higher than the resonant frequency at the stem-end. This is thought to be due to the seed itself, which could influence the vibration pattern. Resonant frequencies showed good correlation to the logarithm of firmness (r=0.87) and therefore were shown capable of monitoring avocado firmness.Item Open Access Biochemical and textural ripeness assessment of avocado fruit from different origins(Ishs; 1999, 2010-10-06T00:00:00Z) Landahl, Sandra; Meyer, Marjolaine D.; Terry, Leon A; Herppich, W. B.Stage of ripeness and quality of avocado is notoriously difficult to assess by conventional methods. Texture is a very important determinant of avocado fruit quality and can change radically during storage. The difficulties in determining avocado quality are related, in part, to the spatial heterogeneity of fruit characteristics during ripening. The aim of this study was to assess the discriminatory capabilities of physiochemical properties to determine ripeness of imported 'Hass' avocado fruit. Fruit were stored at 12°C and sampled at regular intervals. Using a previously unreported method, the texture of different slices from individual fruit was measured during ripening. Maximum load, elasticity and viscosity of fruit tissue were measured using a universal testing machine fitted with a 500N or 5N load cell. The same tissue slice was then further processed prior to subsequent quantification of non-structural carbohydrates (NSCs) and fatty acid methyl esters using standard high performance liquid chromatography coupled to evaporative light scattering detection and gas chromatography coupled to flame ionisation detection, respectively. Spatio-temporal differences in maximum load, elasticity, viscosity, NSCs and fatty acid composition were found in avocados from different origins. Results of measured texture and target analytes were used to differentiate avocado fruit into definable groups using partial least squares discriminant analysis.Item Open Access Biochemical profile of heritage and modern apple cultivars and application of machine learning methods to predict usage, age, and harvest season(American Chemical Society, 2017-06-02) Anastasiadi, Maria; Mohareb, Fady R.; Redfern, Sally P.; Berry, Mark; Simmonds, Monique; Terry, Leon AThe present study represents the first major attempt to characterise the biochemical profile in different tissues of a large selection of apple cultivars sourced from the UK’s National Fruit Collection comprising dessert, ornamental, cider and culinary apples. Furthermore, advanced Machine Learning methods were applied with the objective to identify whether the phenolic and sugar composition of an apple cultivar could be used as a biomarker fingerprint to differentiate between heritage and mainstream commercial cultivars as well as govern the separation among primary usage groups and harvest season. Prediction accuracy > 90% was achieved with Random Forest for all three models. The results highlighted the extraordinary phytochemical potency and unique profile of some heritage, cider and ornamental apple cultivars, especially in comparison to more mainstream apple cultivars. Therefore, these findings could guide future cultivar selection on the basis of health-promoting phytochemical content.Item Open Access Biomarkers of postharvest resilience: unveiling the role of abscisic acid in table grapes during cold storage(Frontiers, 2023-09-29) Navarro-Calderón, Ángela; Falagán, Natalia; Terry, Leon A; Alamar, M CarmenTable grapes are considered non-climacteric fruit, not showing a rapid increase in respiration rate and ethylene production during ripening. Previous research has suggested that abscisic acid (ABA) may have a more crucial role in grape postharvest behaviour. This study aimed to identify biomarkers of postharvest resilience and flavour life of imported table grapes. An experiment was designed to determine i) the role of ABA and catabolites on grape berry senescence; ii) the spatial distribution of these hormones within the grape berry, and iii) the effect of 1-MCP and storage temperature on its postharvest quality. Hence, the use of an ethylene inhibitor, 1-methylcyclopropane (1-MCP), during table grape storage was investigated. Table grapes (Vitis vinifera L.) cv. ‘Krissy’ were subjected to i) control (untreated); and ii) 1-MCP (1 µL L-1; 12 hours; 15°C) and stored under two scenarios: i) 15 days at 0.5°C, followed by five days at 5.5°C to simulate shelf-life; and ii) 20 days at 5.5°C to simulate a higher storage temperature followed by shelf-life. Physiological (i.e. mould incidence, skin colour, firmness, respiration rate) and biochemical analysis (i.e. individual sugars, organic acids, abscisic acid and catabolites) were performed. Grapes subjected to 5.5°C showed significantly higher mould incidence at the end of the shelf-life compared to 0.5°C storage temperature (12.6% vs. 3.1%). Also, and for the first time, the spatial distribution of ABA during the senescence of table grapes was profiled; the distal section had three times more ABA and metabolites than the proximal. We demonstrated that senescence processes were initiated after a significant increase in respiration rate (from 1 to 2.8 mL CO2 kg-1 h-1), and that ABA could be considered a biomarker for table grapes senescence, since an ABA peak preceded the increase in respiration rate, mould incidence, organic acids, and sucrose hydrolysis during postharvest storage; and coincided with a decrease in berry firmness. These findings are of significant importance for the industry as understanding how ABA regulates both senescence processes and quality changes during postharvest cold storage of tables grapes can improve the consistency and reduce waste and consumer complaints.Item Open Access Characterization of industrial onion wastes (Allium cepa L.): dietary fibre and bioactive compounds.(2011-03-31T00:00:00Z) Benítez, Vanesa; Mollá, Esperanza; Martín-Cabrejas, María A.; Aguilera, Yolanda; López-Andréu, Francisco J.; Cools, Katherine; Terry, Leon A; Esteban, Rosa M.The food industry produces a large amount of onion wastes, making it necessary to search for possible ways for their utilization. One way could be to use these onion wastes as a natural source of high-value functional ingredients, since onion are rich in several groups of compounds, which have perceived benefits to human health. The objective of this work is to gain knowledge of any differences between the different onion wastes obtained from industry and non-commercial bulbs to use them as food ingredients rich in specific compounds. The results showed that brown skin and top-bottom could be potentially used as functional ingredient rich in dietary fibre, mainly in insoluble fraction, and in total phenolics and flavonoids, with high antioxidant activity. Moreover, brown skin showed a high concentration of quercetin aglycone and calcium, and top-bottom showed high concentration of minerals. Outer scales could be used as source of flavonols, with good antioxidant activity and content of dietary fibre. However, inner scales could be an interesting source of fructans and alk(en)yl cystein sulphoxides. In addition, discarded onions (cvs Recas and Figueres) could be used as a good source of dietary fibre, and cv Recas also as a source of phenolics compounds.Item Open Access Combining conventional QTL analysis and whole-exome capture-based bulk-segregant analysis provides new genetic insights into tuber sprout elongation and dormancy release in a diploid potato population(Nature Publishing Group, 2021-07-30) Sharma, Sanjeev Kumar; McLean, Karen; Colgan, Richard J.; Rees, Debbie; Young, Stephen; Sønderkær, Mads; Terry, Leon A; Turnbull, Colin; Taylor, Mark A.; Bryan, Glenn J.Tuber dormancy and sprouting are commercially important potato traits as long-term tuber storage is necessary to ensure year-round availability. Premature dormancy release and sprout growth in tubers during storage can result in a significant deterioration in product quality. In addition, the main chemical sprout suppressant chlorpropham has been withdrawn in Europe, necessitating alternative approaches for controlling sprouting. Breeding potato cultivars with longer dormancy and slower sprout growth is a desirable goal, although this must be tempered by the needs of the seed potato industry, where dormancy break and sprout vigour are required for rapid emergence. We have performed a detailed genetic analysis of tuber sprout growth using a diploid potato population derived from two highly heterozygous parents. A dual approach employing conventional QTL analysis allied to a combined bulk-segregant analysis (BSA) using a novel potato whole-exome capture (WEC) platform was evaluated. Tubers were assessed for sprout growth in storage at six time-points over two consecutive growing seasons. Genetic analysis revealed the presence of main QTL on five chromosomes, several of which were consistent across two growing seasons. In addition, phenotypic bulks displaying extreme sprout growth phenotypes were subjected to WEC sequencing for performing BSA. The combined BSA and WEC approach corroborated QTL locations and served to narrow the associated genomic regions, while also identifying new QTL for further investigation. Overall, our findings reveal a very complex genetic architecture for tuber sprouting and sprout growth, which has implications both for potato and other root, bulb and tuber crops where long-term storage is essential.Item Open Access A comprehensive study of factors affecting postharvest disorder development in celery(Elsevier, 2020-11-05) Anastasiadi, Maria; Falagán, Natalia; Rossi, Simone; Terry, Leon AFresh-cut celery is an economically important crop, susceptible to postharvest disorders such as browning at cut ends, which can compromise quality and affect freshness perception. The study herein represents the most comprehensive attempt to date to determine the factors that mediate celery postharvest disorders and uncover the physiological and biochemical mechanisms involved. Three main experiments were conducted over two years, covering the early and late Spanish season and the late UK season. The aim of the experiments was to study: a) the effect of seasonal variation and horticultural maturity on shelf-life (20 °C) of fresh-cut celery; b) the effect of postharvest application of 1-methylcyclopropene (1-MCP) and continuous ethylene supplementation on browning and pithiness development during cold storage (5 °C); and c) the effect of preharvest deficit irrigation on the quality of fresh-cut celery during shelf-life (20 °C). Lesser horticultural maturity increased browning and pithiness with browning severity being positively correlated with chlorogenic acid concentrations in celery cut-ends. Ethylene supplementation accelerated the metabolic activity of celery, leading to early senescence. We found that 1-MCP suppressed respiration rate and delayed browning. Deficit irrigation promoted browning, which coincided with a rapid increase in abscisic acid and its main catabolite phaseic acid during storage. Mild deficit irrigation promoted the increase of chlorogenic acid after 6 d of storage, while severe deficit irrigation did not show this increase. These findings will help growers and retailers standardise industry practices ensuring uniform quality and better shelf-life estimations.Item Open Access Continuous exposure to ethylene differentially affects senescence in receptacle and achene tissues in strawberry fruit(Frontiers, 2020-03-12) Tosetti, Roberta; Elmi, Fardusa; Pradas, Inmaculada; Cools, Katherine; Terry, Leon AStrawberry shelf life is limited, and little is known about the postharvest regulation of senescence in different fruit tissues. Strawberry is classified as a non-climacteric fruit, yet it is known that ethylene affects strawberry ripening. Here the effects of continuous exogenous ethylene (50 µl l−1) were investigated in cold stored strawberry (5°C). The physiological and biochemical responses of ripe strawberry were evaluated across 6 days, together with hormonal profiles of the whole fruit and individual tissues (achenes and receptacle). Continuous exposure to ethylene induced as a first response an accumulation of abscisic acid (ABA) in the receptacle tissue, followed by an increase in CO2 production. Ethylene also elicited sucrose hydrolysis and malic acid catabolism, with the major effect seen after 4 days of ethylene exposure. Additionally, accumulation of phenolics (epicatechin and chlorogenic acid) were also observed in ethylene treated strawberry. Achenes did not exhibit a response to ethylene, yet catabolism of both ABA and auxins increased by two thirds during air storage. In contrast, ethylene induced ABA accumulation in the receptacle tissue without ABA catabolism being affected. This hormonal disequilibrium in response to ethylene between the two tissues was maintained during storage, and therefore might be the precursor for the following biochemical variations reported during storageItem Open Access Cultivar and tissue-specific changes of abscisic acid, its catabolites and individual sugars during postharvest handling of flat peaches (Prunus persica cv. platycarpa)(Elsevier, 2021-08-20) García-Pastor, María E.; Falagán, Natalia; Giné-Bordonaba, Jordi; Wójcik, Dorota A.; Terry, Leon A; Alamar, M CarmenThe role of abscisic acid (ABA) during postharvest ripening of peaches remains unclear. This study aimed to investigate the temporal and tissue-specific changes in ABA, and ABA catabolites, of two flat peach cultivars, ‘Plane Sun’ and ‘Platibell’, during the stone fruit supply chain. The relationship between ABA catabolism, ethylene production, individual sugar changes and fruit firmness was also studied. We found that flat peaches can produce and metabolise ABA during postharvest ripening, and that this is cultivar and tissue dependent. Our results demonstrated that a burst in ABA concentration preceded that of ethylene production in ‘Plane Sun’ fruit, suggesting cross-talk between the two hormones. ABA and ethylene were both negatively correlated with fruit firmness, whilst sugar content, especially glucose, was only correlated with ABA. In conclusion, ABA may trigger ethylene production changes while also affecting sugar metabolism leading to fruit softening and over-ripening associated processes during stone fruit postharvest handling.Item Open Access Dataset for Controlled atmosphere as cold chain support for extending postharvest life in cabbage(Cranfield University, 2024-09-04) Gage, Ewan; Falagán, Natalia; Terry, Leon AItem Open Access Design and construction of a flexible laboratory-scale mixing apparatus for continuous ethylene supplementation of fresh produce(Elsevier, 2017-03-17) Amoah, Robert S.; Landahl, Sandra; Terry, Leon AThe design and construction of a laboratory-scale apparatus for generating variable concentrations and flow rates of exogenous ethylene for fresh produce supplementation during storage trials is described. A stock of compressed ethylene in nitrogen (5000 μl l−1) was blended into a continuous flow stream of air and diluted to the desired concentrations. The ethylene and air flow rates were controlled with calibrated mass flow control valves. An empirical mathematical model was derived for real-time variation of both the mixed concentration and flow rate during continuous flow. Validation of the model was performed using fresh sweet potato as a case study where a steady continuous ethylene concentration of 10 μl l−1 was achieved for three months. The bespoke system offers easy-to-manage ethylene supplementation for research.Item Open Access Detection of internal defects in onion bulbs by means of single-point and scanning laser Doppler vibrometry(Elsevier, 2022-08-05) Landahl, Sandra; Terry, Leon AThe number of onion consignments which are rejected or downgraded due to the incidence of internal defects is a continuing problem for wholesalers and growers. Defects may only be up to 4% incidence level, but result in the entire lot being lost for sale. Destructive quality control testing causes waste, so that there is a need for alternative non-invasive assessment. The aim of the current research was to demonstrate whether internal defects could be detected using Laser Doppler vibrometry (LDV). Several trials, with different types of sensors and levels of onion defect severity were conducted. Both scanning and single-point LDV were employed in order to develop a suitable measurement method to evaluate onion defects. It was necessary to measure resonant frequency at the neck or equator of the bulbs in order to segregate neck rot (Botrytis allii) or bacterial rot, respectively, but LDV could not differentiate sprouting and double hearted bulbs from sound onions. In conclusion, it was possible to non-destructively identify onion bulbs with only a 5% area affected with neck rot (visible after cutting). It would be necessary to calibrate for different onion cultivars and origins, if the technique is to be implemented on a commercial sorting line.Item Open Access Development of a disposable pyruvate biosensor to determine pungency in onions (Allium cepa L.)(Elsevier, 2006-05-15) Abayomi, Louise Anike; Terry, Leon A; White, S. F.; Warner, P. J.A disposable prototype pyruvate biosensor was constructed using pyruvate oxidase immobilised on mediated meldolas blue electrodes to determine pungency in onions (Allium cepa L.). The optimum operating potential was +150 mV (versus Ag/AgCl). A strong correlation between the biosensor response and untreated onion juice of known pyruvate concentration 2–12 μmol/g fresh weight (FW) was demonstrated. The biosensor was able to differentiate between low and high pungency onions. The detection limit using 1 unit of pyruvate oxidase was 1–2 μmol/g FW. Optimum concentrations of co-factors TPP, FAD and MgSO4 comprising the enzyme cocktail were determined as being 0.04, 0.1 and 30 mM, respectively.Item Open Access Discrete ex situ and continuous in situ real-time respiration rate measurements of fresh produce using a novel automated dynamic approach(International Society for Horticultural Science (ISHS), 2018-04-04) Collings, Emma; Alamar, M Carmen; Cools, Katherine; Ordaz-Ortiz, J. J.; Terry, Leon AFresh produce respiration rate is a useful indicator of metabolic state often used in postharvest research to determine physiological differences between factors. Static (no flow) and dynamic (constant flow) measurements are two types of methods that exist for determining respiration rate in fresh produce. Implementation of an automated real-time respiration method, using a dynamic measurement, for measuring respiration rates of fresh produce in discrete (ex situ) and continuous (in situ) set-ups has been established. Discrete methods were performed on fresh (green) black pepper within 3 L hermetically sealed containers with constant flow rates of 400 mL min-1 and 1 L min-1, respectively. Continuous respiration measurements were also obtained in situ for fresh black pepper stored under air (1.8 L min-1) at 5°C, and avocado fruit stored under air and controlled atmosphere environment (ca. 10 kPa CO2 and 10 kPa O2; 400 mL min-1), at 20°C. In addition, simultaneous automated recordings of O2 and CO2 enabled accurate respiratory quotient (RQ) values to be determined for avocado throughout storage. Application of the continuous dynamic in situ measurements can also provide a more realistic assessment of physiological change / behaviour under real-world storage conditions. In this paper, we discuss the application of both discrete and continuous dynamic methods as powerful research techniques for measuring respiration rate in postharvest research.Item Open Access Effect of deficit irrigation and methyl jasmonate application on the composition of strawberry (Fragaria x ananassa) fruit and leaves(Elsevier, 2015-12-31) Giné-Bordonaba, Jordi; Terry, Leon ADrought stress is among the most severe environmental risks threatening strawberry production. In the present study, the effect of deficit irrigation (DI; 50 mL/day) and/or elicitation with methyl jasmonate (MeJA; 0.1 mM) on the composition of secondary fruit and leaves from three strawberry pre-commercial cultivars (253/29, 279/4 and 279/5) was investigated and compared to plants kept at or near field capacity (200 mL/day). For certain cultivars (253/29), DI applied at green stage of fruit development resulted in a considerable reduction in berry size (1.7-fold). In other cultivars (279/4 and 279/5), fruit size was comparable in DI-treated and fully irrigated plants. Changes in the major sugars and organic acids of strawberry leaves and fruit were cultivar and organ dependent and were associated to an osmotic adjustment strategy within the plant to counteract the effects of drought. Overall, elicitation with MeJA had a minimal effect on plant growth and morphological traits. Nevertheless, MeJA increased fructose content of DI-treated leaves and palliated the differences in glucose content of fruit from different water treatments. The most pronounced effect of MeJA was related to an enchance synthesis and accumulation of pelargonidin-3-glucoside (nearly 2-fold) in red-ripe fruit from cultivar 279/5.Item Open Access Effect of ethylene on postharvest strawberry fruit tissue biochemistry(International Society for Horticultural Science (ISHS), 2017-04-20) Elmi, F.; Pradas, I.; Tosetti, R.; Cools, K.; Terry, Leon AThe effect of continuous ethylene supplementation (50 µL L-1) on cold-stored strawberry fruit physiology and biochemistry, including phytohormone (abscisic acid) metabolism was investigated. In comparison with control fruit which exhibited high sucrose and malic acid contents during storage, ethylene-treated fruits showed increased respiration, sucrose hydrolysis and concomitant reducing sugars accumulation. Ethylene supplementation did not have any effect on phenolic profile. ABA biosynthesis, in both flesh and achenes, was promoted by ethylene. The results herein suggest that controlling ethylene after harvest could suppress senescence and extend shelf-life.Item Open Access Effect of methyl jasmonate and sucrose on endogenous non-structural carbohydrates in petals and leaves of cut ‘First Red’ roses (Rosa hybrida L.)(Islamic Azad University, 2017-06-01) Terry, Leon A; Foukaraki, Sofia G.; Cook, Balwinder; Papadimitriou, Michael D.Effects of exogenously applied methyl jasmonate (MeJA) and sucrose on vase life and non-structural carbohydrate concentration in petals and leaves of cut ‘First Red’ roses were investigated. Roses were placed in sealed plastic containers and received MeJA vapour treatment (0.1 μL MeJA L-1) for 24 h at 20°C. Flowers were then placed in individual bottles containing 0 or 2% (v/v) sucrose solution. Flower petals and the two uppermost five-leaflet leaves were detached on days 0, d 5 and d 10 of vase life. Samples were individually snap-frozen in liquid nitrogen and freeze-dried. Non-structural carbohydrates were extracted and quantified using standard HPLC coupled to evaporative light scattering detection. The MeJA vapour treatment enhanced vase life of flower and foliage of ‘First Red’ roses. Significant differences were observed between foliage life of cut ‘First Red’ roses that were treated with MeJA and sucrose, but not for flower life. Rose stems treated with MeJA in the absence of sucrose had an extended vase life compared to roses treated with 2% sucrose alone (14.0 vs. 12.8 days of vase life). Sucrose and myo-inositol, and to a lesser extent glucose concentrations in petals of cut roses decreased during vase life, even when flowers were supplied with 2% sucrose. Concomitant to this, fructose levels in petals increased during vase life. Neither sucrose nor MeJA had a significant effect on any of the sugars measured in petals of cut roses. In contrast, significant differences were apparent for all sugars measured in leaves that were treated with MeJA and sucrose solutions. The combination of MeJA and 2% sucrose solution sharply increased endogenous sucrose concentration in leaves, but the opposite was shown in the absence of 2% sucrose. Sucrose treatment alone did not consistently alter endogenous sucrose concentration. Interactions between MeJA and sucrose on sugar metabolism are discussed.
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