Flesh Disorder Research Articles

Mangosteen Flesh Condition Detector Based on Microwave Non-destructive Technique Using Spiral Resonator Sensor’s

The mangosteen fruit has a characteristic thick skin, so it is difficult to know the condition of the flesh. Farmer can only know damage to the fruit flesh after the fruit skin had opened. Detection of the quality of the mangosteen flesh can be detected using a sensor capable of penetrating the thickness of the mangosteen rind. Flesh quality detection is carried out based on the S21 value (attenuation of mangosteen flesh value) using a portable device equipped with a sensor and capable of emitting microwaves. The S21 value of the fruit's flesh was measured using a spiral resonator that functioned as a sensor. The prototype device consists of an oscillator circuit, a power splitter, and a phase detector with 2507 MHz. Fruit flesh had divided into two conditions: damaged for fruit flesh with yellow sap or Translucent Flesh Disorder, and suitable condition for clean fruit flesh. The results showed that the fruit flesh had an average S21 value of 7.041 dB for damaged flesh and 6.007 dB for good flesh condition. The difference in the value of S21 had used as a reference for detecting the shape of the fruit flesh, with the detection threshold calculated by the Support Vector Machine, resulting in a threshold value of 6.712 dB.

‘Hass’ Avocado Internal Disorders under Simulated Export Conditions and Its Relationship with Flesh Mineral Content and Preharvest Variables

The most important issues that affect consumer fruit acceptance in the ‘Hass’ avocado international market are flesh disorders. These defects can be influenced by both pre- and postharvest factors. The aim of this work was to evaluate the effect of the harvest season, storage time, mineral content, and preharvest variables on internal fruit disorders. Here, fruit was sampled from four farms in Antioquia (Colombia) at 22%, 26%, and 30% dry matter (DM) content. Samples were stored and ripened under simulated export conditions. Then, flesh bruising, flesh discoloration, body rots, vascular browning, stem end rot, and mineral content were assessed. The results showed that flesh disorders differ among farms and by harvest index and storage time. The most frequent defects found were vascular browning and stem end rot. Boron, calcium, nitrogen, manganese, magnesium, and potassium have a strong relationship with flesh disorders. Therefore, high boron and calcium contents, as well as a harvest at 26% DM, can substantially reduce avocado flesh disorders and improve internal fruit quality. Farmers that had a high flesh and soil mineral content and low rainfall and temperature produced fruits with fewer internal disorders.

Contribution of several fruit quality factors and mineral elements to water-soaked brown flesh disorder in peaches

Water-soaked brown flesh disorder in peach [Prunus persica (L.) Batsch] fruit is a known physiological disorder which can affect the economic value of peach crops. The disorder is more severe in high-quality fruit when maturity and/or ripening advanced. Principal component analysis (PCA) of fruit with different qualities and mineral concentrations showed that factors contributing to the first component (PC1) were total soluble solids (TSS), fruit weight, pH, B and Ca concentrations, the ratios of Ca:K, Ca:Mg and Ca:(Mg + K), and the severity of the disorder. Firmness was not grouped in PC1. When firmness was low, the disorder appeared in fruit with high TSS (> 15 %) and low Ca concentration (< 24 mg kg−1 FW). CaCl2 application significantly increased Ca concentration in the fruit and reduced the symptoms of the disorder. A bagging treatment to minimize fruit transpiration significantly decreased the Ca concentration during the growing period and in the apoplast of the flesh at harvest, resulting in increased symptoms of the disorder. These results indicated that as well as fruit quality factors, such as TSS, pH and fruit weight, Ca concentration is involved in this disorder. Because the contribution of Ca was not strong compared to the other factors, the effect of Ca on the disorder should be considered in terms of its relationships with other contributing factors, such as the condition of the tree and its environment.

Food Quality, Sensory Attributes and Nutraceutical Value of Fresh “Osteen” Mango Fruit Grown under Mediterranean Subtropical Climate Compared to Imported Fruit

Mango is a fruit with a very short shelf-life due to its rapid ripeness after harvest; it is high in B vitamins, contains some amounts of magnesium, calcium, zinc, and selenium and it is rich in soluble and insoluble fibers. In order to reach the European markets at proper marketable maturity, fruit from tropical countries are harvested at early maturity stage. Although this harvesting practice improves mango postharvest life, fruit reach the market with very low quality, especially in terms of taste. The present study was conducted to evaluate food quality, sensory attributes and nutraceutical value of “Osteen” fresh Mediterranean Italian mango fruit, and imported ones coming from tropical countries. Mango fruit imported from abroad were collected from 5 large-scale organized markets; fresh Italian mango fruit were harvested from a commercial orchard, at green- and mature-ripe stage. Imported and fresh Italian mango fruit were analyzed in terms of firmness, total soluble solids content, titratable acidity, flesh disorders, nutraceutical value, and sensory attributes. Mediterranean Italian mango fruit showed the best quality performances in terms of nutraceutical value and quality attributes. Sensorial analysis confirmed this behavior, these quality attributes, were perceived by the trained panel, that preferred fresh Mediterranean mango fruit.

Red to Brown: An Elevated Anthocyanic Response in Apple Drives Ethylene to Advance Maturity and Fruit Flesh Browning.

The elevation of anthocyanin contents in fruits and vegetables is a breeding target for many crops. In some fruit, such as tomato, higher anthocyanin concentrations enhance storage and shelf life. In contrast, highly anthocyanic red-fleshed apples (Malus x domestica) have an increased incidence of internal browning flesh disorder (IBFD). To determine the mechanisms underlying this, ‘Royal Gala’ cultivar apples over-expressing the anthocyanin-related transcription factor (TF) MYB10 (35S:MYB10), which produces fruit with highly pigmented flesh, were compared with standard ‘Royal Gala’ Wild Type (WT) grown under the same conditions. We saw no incidence of IBFD in WT ‘Royal Gala’ but the over-expression of MYB10 in the same genetic background resulted in a high rate of IBDF. We assessed concentrations of potential substrates for IBDF and a comparison of metabolites in these apples showed that anthocyanins, chlorogenic acid, pro-cyanidins, flavon-3-ols, and quercetin were all higher in the MYB10 lines. For the flavol-3-ols sub-group, epicatechin rather than catechin was elevated in MYB10 lines compared with the control fruit. Internal ethylene concentrations were measured throughout fruit development and were significantly higher in 35S:MYB10 lines, and ethylene was detected at an earlier developmental stage pre-harvest. Expression analysis of key genes associated with ethylene biosynthesis (aminocyclopropane-1-carboxylic acid synthase and oxidase; ACS and ACO) and polyphenol oxidase (PPO) showed the potential for increased ethylene production and the mechanism for enhanced PPO-mediated browning. The expression of a transcription factor of the ethylene response factor (ERF) class, ERF106, was elevated in red flesh. Analysis of transcriptional activation by MYB10 showed that this transcription factor could activate the expression of apple ACS, ACO, and ERF106 genes. Our data show a link between the elevation of anthocyanin-related transcription factors and an undesirable fruit disorder. The accelerated advancement of maturity via premature ethylene induction has implications for the breeding and storage of these more highly pigmented plant products.

Comparative transcriptome analysis of translucent flesh disorder in mangosteen (Garcinia mangostana L.) fruits in response to different water regimes.

Translucent flash disorder (TFD) is one of the important physiological disorders in mangosteen (Garcinia mangostana L.). TFD has symptoms such as flesh arils that become firm and appear transparent similar to watercore in apple or pear. Information on the changes of gene expression in TFD-affected tissues remain limited, and investigations into the effects of different water regimes still need to be undertaken. Through an RNA sequencing approach using the Ion Proton, 183,274 contigs with length ranging from 173–13,035 bp were constructed by de novo assembly. Functional annotation was analyzed using various public databases such as non-redundant protein NCBI, SwissProt, and Gene Ontology, and KEGG pathway. Our studies compared different water regimes to incidence and differentially expressed genes of TFD-like physiological disorders. From the differentially expressed gene (DEG) between normal air and TFD-affected aril, we identified DEG-related TFD events, which 6228 DEGs in the control condition and 3327 DEGs in under water stress treatment condition remained, and confirmed these with RT-qPCR, including sucrose synthase (SUSY), endoglucanase (GUN), xyloglucan endotransglucosylase/hydrolase (XTH), and polygalacturonase (PG) showed statistically significant. In addition, transcription factors also indicated changes in MYB, NAC and WRKY between tissues and different water regimes.

Monitoring the growth and maturation of apple fruit on the tree with handheld Vis/NIR devices

Modern computer-controlled fruit grading and sorting facilities, with non-destructive Vis/NIR technologies based on transmission spectroscopy are now common. The main applications, at least in apple sorting, are not only to identify internal browning disorders in fruit after storage but also to grade out fruit with physiological conditions like watercore (fluid filled, glassy looking areas within the fruit flesh) in the period after harvest but before long-term storage. Usually, both these types of internal flesh disorders are not visible from the outside of the apple; thus, high-speed Vis/NIR non-destructive sorting of the individual fruit has been a considerable advancement for the fruit industry to ensure the supply of good quality apples to the end consumer.

Corrigendum to “Capillary Water in Pericarp Enhances Hypoxic Condition during On-Tree Fruit Maturation That Induces Lignification and Triggers Translucent Flesh Disorder in Mangosteen (Garcinia mangostana L.)”

Corrigendum to “Capillary Water in Pericarp Enhances Hypoxic Condition during On-Tree Fruit Maturation That Induces Lignification and Triggers Translucent Flesh Disorder in Mangosteen (<i>Garcinia mangostana</i> L.)”

Capillary Water in Pericarp Enhances Hypoxic Condition during On-Tree Fruit Maturation That Induces Lignification and Triggers Translucent Flesh Disorder in Mangosteen (Garcinia mangostanaL.)

Translucent flesh of mangosteen normally occurs during fruit ripening. Rainfall, after water stress, enhanced on-tree mature green fruit to develop translucent flesh disorder more frequently. Thus, this research pursued the effect of applied water on translucent flesh disorder development. The on-tree mature green stage fruits were selected and wrapped with 3 layers of fabric sheet. After that, water was continuously dropped (flow rate of 0.6 ml/min) on the wrapped sheet for 0, 1, and 2 days before picking. The results showed that duration time of water applying enhanced the increasing of water absorption significantly in peel. All of water-treated fruits ripened within 2-3 days after harvest and obviously had high lignin in secondary cell wall. It was hypothesized that lignification played an important role in hypoxia defense mechanism since the Na2CO3-SP fractionation extracted from alcohol insoluble residue (AIR) of translucent flesh aril was higher than those of normal aril. This Na2CO3-SP reinforced the strength of cell wall complexity as well as displaying the translucency character. Hence, we concluded that the capillary water (took place in intercellular air space of fruit pericarp) induced hypoxia tolerance mechanism that triggered translucent flesh disorder in mangosteen aril.

Patterns of flesh reddening, translucency, ethylene production and storability of ‘Friar’ plum fruit harvested at three maturity stages as affected by the storage temperature

Flesh reddening and translucency are two predominant physiological disorders of ‘Friar’ plum (Prunus salicina Lindl.) during cold storage. In order to investigate the occurrence of these disorders, the fruit were harvested at early-, mid- and late-maturity stages and stored at 0, 2, 5, 15 or 25°C, 85–95% relative humidity. Three concomitant patterns for flesh reddening, translucency and abnormal softening (melting) of ‘Friar’ plums were evident: rapid increases in these disorders at 5 and 15°C, a delayed/suppressed of these disorders at 0 and 2°C, and normal ripening at 25°C, irrespective of fruit maturity stage. Three similar temperature-mediated patterns of anthocyanin accumulation related to flesh reddening, pectin solubilization related to translucency, and decline in firmness related to abnormal softening were observed. Three patterns of ethylene production were also identified: early and dramatically high ethylene production at 5 and 15°C, suppressed ethylene production at 0 and 2°C, and almost no ethylene production at 25°C. These results suggest that ethylene may be involved in the onset and development of flesh disorders of ‘Friar’ plums during cold storage. Respiration greatly increased, water-soluble pectin content increased early during storage and remained high, and insoluble pectin (i.e., protopectin) decreased, in plums held at 5 and 15°C. Overall, the biochemical and physiological behavior of plums were greatly affected by storage at 5 and 15°C compared with 0, 2 and 25°C, and late-maturity plums were more susceptible to storage disorders.

Effect of antibrowning dips and controlled atmosphere storage on the physico-chemical, visual and nutritional quality of minimally processed "Rojo Brillante" persimmons.

The combined effect of antibrowning dips and controlled atmosphere storage on fresh-cut "Rojo Brillante" persimmon quality was investigated. Persimmon slices were dipped in 10 g L-1 ascorbic acid, 10 g L-1 citric acid or water and were stored in different controlled atmospheres at 5 ℃. Controlled atmosphere conditions were 21 kPa O2 + 10 kPa CO2 (Atm-B), 21 kPa O2 + 20 kPa CO2 (Atm-C), 5 kPa O2 + 10 kPa CO2 (Atm-D) and 5 kPa O2 in the absence of CO2 (Atm-E). Air (Atm-A) was used as a control. Atmospheres with high CO2 concentrations induced darkening, associated with a flesh disorder known as "internal flesh browning". Only the samples placed in Atm-E, and treated with 10 g L-1 ascorbic acid or 10 g L-1 citric acid, controlled enzymatic browning, reduced firmness loss and prevented the "internal flesh browning" disorder. The maximum limit of marketability was achieved in the samples treated with 10 g L-1 citric acid and stored in Atm-E for nine storage days at 5 ℃. The total vitamin C, free radical scavenging activity, total phenolic content and total carotenoids of the fresh-cut "Rojo Brillante" persimmons were affected by maturity stage at harvest, whereas antibrowning dips and controlled atmosphere storage had no clear effect.

FLOWER AND FRUIT THINNING IN RELATION TO SOME FRUIT TRAITS AS AFFECTED BY BLOOM TIME AND WITHIN-TREE POSITION IN PEACH

In Japanese peach culture, unnecessary flowers (buds) such that attach uprightly or toward centre of tree on the bearing shoots are removed simply and lightly by flower thinning and their fruiting levels are adjusted by fruit thinning done at two steps to control number of fruit remaining on the tree. However, fruit quality still varies widely within a tree and flesh disorders such as “reddish pulp” and “water-soaked brown flesh” occur in many of harvested fruit in recent years. We investigated the relationship between fruiting positions or flowering time and the variation in weight, soluble solids content (SSC) and occurrence of flesh disorders of fruit within a peach cv. white flesh type ‘Benishimizu’ tree. Fruit weight and SSC were significantly inferior in not only the fruit located on the bottom part of the main stem but also for the fruit borne from early blooming flowers and the rate of fruit showing severe “reddish pulp” disorder was also higher in these fruit. The fruit borne from early blooming flowers had lower sugar accumulation in the flesh than those from late blooming flowers during the latter half of Stage 3 of fruit growth. At present, we are trying to improve flower thinning so as to remove the flowers opening before full bloom. On fruiting shoots of white flesh type ‘Shimizu Hakuto’ peach that received thinning of early blooming flowers, the distribution rates of fruit that had weights less than 280 g were lower than those of fruiting shoots (= control) that received the standard fruit thinning. Occurrence rate of severe “reddish pulp” disorder when using this flower thinning protocol were significantly lower than the control. Based on the above results, flower and fruit thinning can improve fruit quality by considering not only the within-tree position of fruit but also the flowering time.

Water-Soaked Brown Flesh Disorders in Peach Fruit (&lt;i&gt;Prunus persica &lt;/i&gt;(L.) Batsch)

Water-soaked brown f lesh disorder of peach (Prunus persica (L.) Batsch) fruit, which occurs in unpicked fruit near harvest time, has been a problem in Japan since the 1990s. The affected fruit share the characteristics of more mature fruit in that the fruit are large, sweet, and soft. It has also transpired that high-quality; high-value fruit are more sensitive to the disorder, which exacerbates economic losses. The most susceptible regions of the fruit are those with high sugar content, although the symptoms are not clearly linked to specific cultivars. Investigations into the cause(s) of water-soaked brown flesh disorder of peach fruit have just started, and reports are limited to Japan. In this review, published information about the disorder is reviewed, and a hypothesis for the occurrence of watersoaked brown flesh disorder in peaches is presented.

Chilling-related cell damage of apple (Malus × domestica Borkh.) fruit cortical tissue impacts antioxidant, lipid and phenolic metabolism.

'Soggy breakdown' (SB) is an internal flesh disorder of 'Honeycrisp' apple (Malus × domestica Borkh.) fruit that occurs during low temperature storage. The disorder is a chilling injury (CI) in which visible symptoms typically appear after several weeks of storage, but information about the underlying metabolism associated with its induction and development is lacking. The metabolic profile of flesh tissue from wholly healthy fruit and brown and healthy tissues from fruit with SB was characterized using gas chromatography-mass spectrometry (GC-MS) and liquid chromatograph-mass spectrometry (LC-MS). Partial least squares discriminant analysis (PLS-DA) and correlation networks revealed correlation among ester volatile compounds by composition and differences in phytosterol, phenolic and putative triacylglycerides (TAGs) metabolism among the tissues. anova-simultaneous component analysis (ASCA) was used to test the significance of metabolic changes linked with tissue health status. ASCA-significant components included antioxidant compounds, TAGs, and phytosterol conjugates. Relative to entirely healthy tissues, elevated metabolite levels in symptomatic tissue included γ-amino butyric acid, glycerol, sitosteryl (6'-O-palmitoyl) β-d-glucoside and sitosteryl (6'-O-stearate) β-d-glucoside, and TAGs containing combinations of 16:0, 18:3, 18:2 and 18:1 fatty acids. Reduced metabolite levels in SB tissue included 5-caffeoyl quinate, β-carotene, catechin, epicatechin, α-tocopherol, violaxanthin and sitosteryl β-d glucoside. Pathway analysis indicated aspects of primary metabolism differed according to tissue condition, although differences in metabolites involved were more subtle than those of some secondary metabolites. The results implicate oxidative stress and membrane disruption processes in SB development and constitute a diagnostic metabolic profile for the disorder.

Effect of CO2 deastringency treatment on flesh disorders induced by mechanical damage in persimmon. Biochemical and microstructural studies

Manifestation of flesh browning while commercialising ‘Rojo Brillante’ persimmon is one of the main causes of postharvest loss. It is known that mechanical damage is a decisive factor for browning development and that astringent fruit is less sensitive to this disorder than fruit submitted to a CO2 deastringency treatment under standard conditions (24h, 95% CO2, 20°C). However, there is no information available about the mechanism behind this alteration. In the present study, we evaluated the effect of treatment with high CO2 concentrations applied for 0–40h on the incidence of mechanical impact-induced flesh disorders using biochemical, chromatographic and microstructural techniques. Our results show that the longer the CO2 exposure, the higher the incidence and the greater the severity browning. A deastringency treatment with CO2 results in O2- accumulation in fruit, which is greater the longer treatment is. However, mechanical damage triggers the browning manifestation, resulting in the accumulation of both O2- and H2O2. In this oxidative stress state, which must be greater as higher the level of O2- previously accumulated in the deastringency treatment, insoluble tannins initially uncolour, undergo an oxidation process and turn red-brown, observed as flesh browning. Moreover, we identified a new disorder, “pinkish-bruising”, which is manifested in astringent fruit. The mechanism of this alteration, also associated with mechanical damage, seems similar to that of browning, but the oxidation process would affect soluble tannins.

Determination of translucent content in mangosteen by means of near infrared transmittance

Translucent flesh disorder is undesirable in mangosteen meant for export. However, mangosteens are judged as translucent when the translucent flesh is visible on the pulp surface regardless of the quantity of the internal translucent flesh which may result in some mangosteen assessed as normal having the same amount of translucent flesh content as a mangosteen judged as translucent. The critical amount of translucent flesh to be visible on the pulp surface needs to be determined for assessment purposes. A non-destructive technique to measure the translucent content is a practical tool as the first step towards the establishment of the critical value.A non-destructive model was developed to estimate the translucent content in mangosteens using near infrared transmittance. The translucent area of the flesh section on the fruit surface was used to indicate the translucent content. The effects of the orientation of the fruit and also of the light source to the relative position of the detector as well as the effect of the measurement position of the fruit on the predictive performance were examined. The results showed that the best partial least squares model was achieved with spectra acquired from the fruit position which revealed the largest flesh segment (prediction correlation coefficient was 0.86 and root mean square error of prediction was 7.58%). The horizontal stem–calyx fruit axis and a 135° angle from the light source relative to the detector were the optimal fruit orientation and configuration for measurement.

Effects of harvesting seasons and maturity stages on internal characteristics of the mangosteen having different surface properties

SummaryTranslucent flesh disorder is a major internal physical disorder of mangosteen. The internal characteristics of smooth‐ and coarse‐surface fruits in relation to their respective specific gravity values and sensory characteristics were evaluated for suitable grading process. Study on percentage of the internal characteristics was performed in different external characteristics, different harvesting seasons and different maturity stages of mangosteen. Results showed that internal physical disorders of smooth‐surface fruits were higher than coarse‐surface ones at the level of 63% and 19%, respectively. Average specific gravity of normal‐flesh fruits, mild translucent‐flesh fruits and moderate‐to‐severe translucent‐flesh fruits were observed as 0.97, 1.00 and 1.01, respectively. The sensory characteristics: sweetness, flavour and overall acceptability were significantly (P &lt; 0.05) higher for coarse‐surface fruits compared with smooth‐surface fruits. Both results were inconsistent with market price in which smooth fruit was 50% higher than coarse‐surface fruit.

SOIL CALCIUM APPLICATION AND PRE-HARVEST CALCIUM AND BORON SPRAYS ON MANGOSTEEN FRUIT QUALITY ATTRIBUTES

Mangosteen (Garcinia mangostana L.) is susceptible to translucent flesh disorder (TFD) and gamboge disorder (GD). Both are apparent only on the fruit's flesh making external visual inspection impossible. The influence of soil calcium (Ca) application and pre-harvest Ca and boron (B) sprays on these disorders was investigated in an experimental plot in Chantaburi, Eastern Thailand. The soil was Typic Paleudults with sandy clay loam texture. Five treatments were applied to the mangosteen to investigate the relationship between nutrient concentration and incidence of TFD and GD. These treatments are 1) no treatment (control), 2) soil Ca only, 3) soil Ca and Ca spray, 4) soil Ca and Ca + B spray, and 5) soil Ca and B spray. Soil Ca was applied once as gypsum at 4 kg/tree in September 2004. The Ca spray was applied six times in 2005 and three times in 2007 using 2% CaCl 2 -7H 2 O. The B spray was applied three times each in 2005 and 2007 using 0.25% solubor. The fruit samples were harvested in the middle of May of 2005 and 2007. At harvest, the fruits were separated into three groups based on their size: small ( 90 g). Then, they were classified as normal fruits, TFD fruits, or GD fruits. The concentrations of K, Ca, and B in the flesh, rind and peduncle were analyzed. It was found that the soil Ca application - with or without foliar sprays - significantly reduced the number of TFD. However, the Ca concentration in the flesh did not differ significantly between normal fruits and TFD fruits. Instead, we found that the ratio of K/Ca in the flesh is a good indicator of TFD. The study revealed that high K/Ca ratio led to more TFD in mangosteen. In general, flesh Ca decreased with fruit size while flesh K increased. As a result, larger fruits tend to have more TFD than smaller ones. When soil Ca was applied, the number of GD was significantly lower than the control. The soil Ca treatment became even more effective when combined with B spray or Ca + B spray, particularly the latter. However, treatment of soil Ca together with Ca spray did not reduce GD considerably. Furthermore, it was found that the nutrient concentrations in all parts of GD fruits were not measurably different from normal or TFD fruit. However, it was clear that Ca + B spray along with soil Ca treatment effectively reduced the number of GD. On the other hand, an excessive amount of Ca treatment without the complement of B did not lower the amount of GD fruit. We recommend that soil Ca together with pre-harvest spray of Ca + B is useful for reducing the number of TFD and GD fruits.

Uncommon disorders and decay in near-isogenic lines of melon and reference cultivars

Postharvest disorders and rots can produce important economic losses in fruits stored for long time for exportation. The genetic and physiological basis of some disorders in melon (Cucumis melo L.) are unknown and particularly the possible relation with climacteric behavior. A collection of melon near-isogenic lines (NILs) (SC3-5 and seven more showing climacteric and two non-climacteric ripening pattern) were analyzed to study genetic and physiological aspects of fruit disorders and rots. Two non-climacteric (Nicolás; Inodorus Group; and Shongwan Charmi PI161375, Conomon Group) and two climacteric cultivars (Fado, Reticulatus Group; Védrantais, Cantaloupensis Group) were used as reference. The field was divided in eight blocks containing one three-plant replication for each NIL, two for the parental cultivar Piel de Sapo and one or two for the reference cultivars. Replications evaluated were more than six in the cultivars studied. Plant problems included aphids, powdery mildew, and leaf wind injury. Preharvest fruit disorders included whole fruit cracking in cultivar Védrantais and NIL 5M2, and stylar-end cracking in cultivar Fado. Climacteric NILs with yellow skin were particularly affected by over-ripening, stylar-end cracking, and sunburn during cultivation. At harvest, two NILs showed slight placental tissue necrosis which was inherited from SC and were also detected after storage. Other uncommon disorders seen at harvest or 30 days after storage at 8ºC included warted skin (scarring), flesh discoloration (light brown or translucent areas), hollow flesh disorder, and deep furrow netting inherited from SC. Less common rots included grey mould, bacterial soft rot, Penicillium rot, cottony leak and internal Cladosporium rot. Stylar-end hardness below 20 N·mm-1 was associated with cracking and softening. The incidence of the disorders and rots was too low to confirm that the genetic component played a role in their development.

Mapping Fruit Susceptibility to Postharvest Physiological Disorders and Decay Using a Collection of Near-isogenic Lines of Melon

Melon (Cucumis melo L.) is a perishable fruit that requires refrigeration to extend its shelf life. Postharvest behavior differs substantially among melon varieties due to genetic differences. In this work, we use a collection of near-isogenic lines (NILs) derived from a cross between the Spanish cultivar Piel de Sapo (PS) and an exotic Korean accession ‘Shongwan Charmi’ [SC (PI161375)], each of them with a single introgressed region from SC into the PS background, to detect and map quantitative trait loci (QTLs) involved in postharvest life traits, such as total losses, water-soaking, necrosis of the placental tissue, chilling injury (CI), decay, fruit over-ripening, flesh browning, hollow flesh disorder, and flavor loss during storage. Fruit were examined at harvest and after 35 days at 8 °C. Three QTLs induced desirable quality traits: flv4.1 reduced the loss of fruit flavor after refrigeration, tl8.1 reduced total losses, and fus8.4 reduced the susceptibility to fusarium rot (Fusarium Link). Another 11 QTLs produced a detrimental effect on other quality traits. The NIL population was useful for dissecting complex, difficult-to-measure pre- and postharvest disorder traits of different degrees of development and for investigating flavor loss during storage. Further studies with the QTLs described herein will shed light on the genetic control of melon shelf life and help breeders who are interested in this fruit quality trait.