Soggy Breakdown Research Articles

A DNA test for high incidence of soft scald and soggy breakdown postharvest disorders in Malus domestica Borkh

The ‘Honeycrisp’ apple, an economically important cultivar and breeding parent, is prone to soft scald and soggy breakdown postharvest physiological disorders. Phenotypic evaluation of soft scald is time consuming and costly, making it an excellent target for DNA-informed breeding. The objective of this study was to develop a DNA test for a soft scald and soggy breakdown quantitative trait locus (QTL) on linkage group two (LG2) that was characterized in a previous study. ‘Honeycrisp’ is homozygous for the undesirable high disorder incidence haplotype (HDI) at this QTL. In this study, sixteen single nucleotide polymorphism markers were evaluated for their associations with the HDI haplotype in a set of 132 unique cultivars and important breeding parents. A DNA test was successfully developed utilizing KASP™ (Kompetitive Allele Specific PCR) chemistry to identify the number of HDI haplotypes in individuals. This test had a 100% accuracy for detecting homozygous unfavorable HDI individuals and has an expected 88% accuracy over all three haplotype copy groups across the evaluated germplasm. This DNA test is a promising tool for minimizing the chances of selecting individuals that exhibit high incidence of soft scald postharvest disorder in ‘Honeycrisp’-related germplasm.

Postharvest quality implications of preharvest treatments applied to enhance Ambrosia™ apple red blush colour at harvest

Two approaches for enhancing red blush in Ambrosia™ apple were evaluated: (i) reflective row covers or (ii) application of foliar phosphorus-rich sprays, both applied several weeks before anticipated harvest. Two experiments were conducted, the first to evaluate a white reflective row cover versus foliar phosphorus spray, and the second to evaluate two types of reflective row cover, one made of a woven white polyethylene sheet and the other a solid silvered Mylar®. The comparative effects of these preharvest treatments on at-harvest fruit quality and quality after storage were assessed in both experiments. It was determined that foliar phosphorus sprays or one of the two types of reflective row covers resulted in similar enhancement of red blush colour, with no negative effects on at-harvest quality. However, in the first experiment it was found that after 8 mo of controlled-atmosphere storage (1 kPa O2 + 1 kPa CO2 at 0.5 °C), apples from the phosphorus foliar spray treatment developed greasiness and sooty blotch compared with those from the reflective row cover or control treatments. In the second experiment, after 5 mo of air storage at 0.5 °C, the apples from the silvered Mylar® reflective row cover treatment developed severe soft scald and soggy breakdown compared with the control and white reflective row cover treatments, which developed lower or very slight incidence of soft scald, respectively, and no soggy breakdown. These results indicate that when preharvest treatments are applied to apples, post-storage quality effects should be evaluated.

Initial Short-term Storage at 33 °F Reduces Physiological Disorder Development in ‘Honeycrisp’ Apples

Initial short-term storage is a treatment where fruit are cooled to 33 °F for a specific time period and then moved to 38 °F until the end of storage. Its effects on the development of physiological disorders in ‘Honeycrisp’ apples (Malus domestica) were investigated for two seasons. During the first season, fruit were harvested from two orchards and stored at 33 and 38 °F, with and without 1 week of conditioning at 50 °F, or stored for 4 weeks at 33 °F followed by 4 weeks at 38 °F. All fruit were stored for a total of 8 weeks. In the second season, fruit were harvested from one orchard and stored at 38 °F either with or without 1 week of conditioning at 50 °F, or stored for 1 week at 33 °F and moved to 38 °F for 15 weeks followed by 7 d at 68 °F. Short-term storage (1 to 4 weeks) at 33 °F decreased bitter pit for all orchards in the two seasons, except in comparison with the continuous 33 °F storage in the first season; soft scald was also reduced in the first season compared with continuous storage at 33 °F, with higher incidence of soft scald in orchard one compared with orchard two. Initial short-term storage at 33 °F resulted in lower soggy breakdown incidence compared with storage at 33 °F with 1 week of conditioning at 50 °F for fruit from orchard two in the first season, the only year when low-temperature injuries were observed. In conclusion, initial short-term storage at 33 °F followed by storage at 38 °F maintained the highest percentage of healthy fruit in the two seasons.

Two QTL characterized for soft scald and soggy breakdown in apple (Malus \xd7 domestica) through pedigree-based analysis of a large population of interconnected families

Soft scald and soggy breakdown are important postharvest physiological disorders of apple (Malus × domestica). ‘Honeycrisp’ and some of its offspring are particularly susceptible to developing these disorders. The purpose of this study was to identify molecular markers associated with high incidences of soft scald and soggy breakdown for use in marker-assisted breeding. Towards this aim, we employed a pedigree-based approach using mostly germplasm related to ‘Honeycrisp.’ Two quantitative trait loci (QTL) were consistently identified on linkage groups (LGs) 2 and 16 across the 2014 and 2015 harvest years. The same QTL were identified for both storage disorders, indicating that they may be physiologically related. ‘Honeycrisp’ is homozygous for an identical by state haplotype at the LG2 QTL that was consistently associated with a deleterious effect on soft scald and soggy breakdown incidence. This haplotype was traced through SNP-confirmed pedigrees to the following cultivars: ‘Grimes Golden,’ ‘Northern Spy,’ ‘Rome Beauty,’ and ‘Fireside’ and is common in derived apple germplasm. Haplotypes at the LG16 QTL could not be adequately characterized due to variation between years combined with effects of this QTL being of relatively smaller size and being most evident in individuals that carry two copies of the deleterious haplotype at the LG2 QTL. These results suggest that limiting homozygosity of the deleterious haplotype at the LG2 QTL through marker-assisted breeding would be a valid strategy to limit soft scald and soggy breakdown incidences in apple seedling populations.

Modeling the Effect of Preharvest Weather Conditions on the Incidence of Soggy Breakdown in ‘Honeycrisp’ Apples

‘Honeycrisp’ is a relatively new apple cultivar highly susceptible to physiological disorders, such as soggy breakdown. The overall objective of this study was to identify preharvest weather parameters that influence the incidence of soggy breakdown over the different phases of fruit development. Using weather data and evaluation of fruit quality from three sites in Ontario, two sites in Quebec, and one site in Nova Scotia from 2009 to 2011, and data from four sites in Ontario from 2002 to 2006, a model for soggy breakdown incidence (SBI) was developed to predict the level of susceptibility in ‘Honeycrisp’ apples. This model uses primarily two weather variables during the last phase of fruit development [91 days from full bloom (DFB) to harvest] to accumulate an SBI index during the growing season, from full bloom to harvest. Cool (temperature <5 °C) and wet conditions (precipitation >0.5 mm) during this last phase resulted in increased soggy breakdown susceptibility levels. The predictions of the SBI model resulted in 68% of well-estimated cases (threshold of ±5%) (RMSE = 6.45, EF = 0.28, E = −0.04). Furthermore, firmness was linked to soggy breakdown, in addition to weather conditions, revealing a positive effect of high firmness at harvest on the development of the disorder. However, the effect of fruit quality attributes (e.g., internal ethylene concentration, starch index, firmness, and soluble solid content) by themselves, without considering weather conditions, revealed no relationship with the incidence of soggy breakdown.

Controlled Atmosphere Storage, Temperature Conditioning, and Antioxidant Treatment Alter Postharvest ‘Honeycrisp’ Metabolism

The physiology and metabolism characterizing postharvest chilling and CO2 injury in apple has important implications for postharvest management of soft scald and soggy breakdown. This research assessed differences of primary metabolism related to soggy breakdown (cortex CI) and CO2 cortex injury in ‘Honeycrisp’ apple fruit. Results indicate that prestorage temperature conditioning, diphenylamine (DPA), and CA treatments alter fruit metabolism and affect peel and cortex storage disorder outcome. A preliminary summary of primary metabolism involved with soggy breakdown under high CO2 includes increased activity in glycolysis/gluconeogenesis, propionate metabolism, and alanine, aspartate, and glutamate metabolism.

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.

Relationships among postharvest ripening attributes and storage disorders in ‘Honeycrisp’ apple

Introduction . The objective of this study was to examine the relationships among the ripening attributes of ‘Honeycrisp’ apples at harvest and after storage, and the direct and indirect contributions of these attributes to peel greasiness and the incidence of soft scald and soggy breakdown during storage using correlation and path-coefficient analyses. Materials and methods . Fruit were harvested from a commercial orchard at least five times throughout the commercial harvest period during four subsequent years (2008 to 2011). In two of the years, fruit were stored in air for 3 months at 3 °C and/or in a controlled atmosphere (1–2 kPa O2 + 1–2 kPa CO2) for 6 months at 3 °C. Fruit were analyzed at harvest and after storage. Results and discussion . Negative correlations were detected between internal ethylene concentration (IEC) and soluble solids concentration (SSC) or titratable acidity (TA) (the higher the IEC, the lower the SSC and TA) and a positive correlation between firmness and TA (the higher the firmness, the higher the TA). More peel greasiness and higher incidence of soggy breakdown during storage were associated with lower firmness, SSC and TA. Negative correlations were also detected between the incidence of soft scald and IEC or peel greasiness. The results of the path-coefficient analyses suggest that, in ‘Honeycrisp’, interrelationships among postharvest ripening indices and each individual disorder differ. Three possible path models for the interrelationships among ripening attributes (independent variables) and the incidence of peel greasiness, soft scald and soggy breakdown (dependent variables) are presented.

Effect of fruit maturity on the incidence of bitter pit, senescent breakdown, and other post-harvest disorders in ‘Honeycrisp’tm apple

SummaryThis study examined the effect of harvest date (fruit maturity) on the occurrence of post-harvest disorders in ‘Honeycrisp’tm apple (Malus × domestica Borkh.). Fruit were sampled from six commercial orchards in the Annapolis Valley, Nova Scotia, Canada over two growing seasons and seven (in 2008) or nine harvest dates (in 2009). After 3 months storage in refrigerated air at 3.5ºC without delayed-cooling, soft scald, low temperature breakdown (LTB; also called soggy breakdown), bitter pit, and senescent breakdown developed in the fruit and the incidence of each varied with harvest date. Bitter pit developed in immature fruit and declined with harvest date, whereas senescent breakdown was non-existent in immature fruit and increased with harvest date. Minimum bitter pit plus senescent breakdown (combined) occurred at the mid-point of the harvest period (at approx. week-5), when internal ethylene was just beginning to appear in the fruit. An increase in fruit size (to ≥ 250 g) appeared to increase the occurrence of these two disorders. This study has shown that there is an optimum maturity (harvest date) in ‘Honeycrisp’tm apples, when the fruit are of sufficient size and colour to meet market requirements, with minimum risk of manifesting the two calcium-related disorders, bitter pit and senescent breakdown. The incidence of these two disorders may increase if fruit are picked earlier (bitter pit) or later (senescent breakdown), especially in larger fruit (≥ 250 g).

Effects of Preconditioning and Fruit Maturity on the Occurrence of Soft Scald and Soggy Breakdown in ‘Honeycrisp’ Apples

Preconditioning, holding fruit at 10, 17.5, or 21 °C temperatures for up to 7 days before placement in cold storage, was inconsistent in its effect on soft scald and soggy breakdown in ‘Honeycrisp’ apples in Maine and Ontario. In Ontario, 4 days of preconditioning at 21 °C increased soft scald in 1 year but had no effect in the next year. Five d of preconditioning at 10 °C reduced soft scald and had no effect on soggy breakdown in 1 year but reduced it the next year. In Maine, 5 days preconditioning at 17.5 °C was effective in reducing soft scald and/or soggy breakdown in 2002 to 2007 when starch index at harvest was 5.9 to 7.2. Seven days of preconditioning at 17.5 °C increased soggy breakdown with an early harvest in two orchards but only in one of two orchards with a later harvest. This same preconditioning had no effect on soft scald with the first harvest but reduced it with the second. In the next year, the same preconditioning treatment increased soft scald and soggy breakdown with an early maturity but had no effect with a later maturity in one orchard but not in fruit from another. Conditions during preconditioning and subsequent cold storage temperatures varied from previous recommendations, and this may be why preconditioning was not consistent in our studies and in some cases increased chilling disorders.

Preharvest 1-Methylcyclopropene Treatment Reduces Soft Scald in ‘Honeycrisp’ Apples during Storage

The main objective of this study was to investigate the effectiveness of preharvest 1-methylcyclopropene (1-MCP) treatment on the development of soft scald in ‘Honeycrisp’ apples. In addition, the effects of preharvest 1-MCP on fruit quality at harvest and after storage were examined. For two consecutive years of study, ‘Honeycrisp’ trees were sprayed preharvest with 1-MCP and fruit were harvested twice during each year. Preharvest 1-MCP treatments had little consistent effect on fruit maturity at the time of harvest. In both years of study, preharvest 1-MCP reduced the incidence of soft scald in ‘Honeycrisp’ apples after air storage at 0 or 3 °C for 5 or 6 months. Soggy breakdown developed only in the second year of study and high incidences were reduced by preharvest 1-MCP treatments. Preharvest 1-MCP often reduced flesh firmness loss in ‘Honeycrisp’ during storage, especially during the second year of study, and with 1-MCP application closer to harvest. Malic acid content was often higher in apples with the preharvest 1-MCP spray closer to harvest. Overall, the most important benefit of preharvest 1-MCP treatments on ‘Honeycrisp’ apples was the reduction in soft scald development. Due to the high potential for substantial fruit losses from this disorder, the use of preharvest 1-MCP sprays on ‘Honeycrisp’ apples could be very advantageous.

(48) Prestorage Delay Effects on Soft Scald and Soggy Breakdown of `Honeycrisp' Apples

In 2004, prestorage delays and CA storage were compared for occurrence of disorders. Fruit were harvested at a starch index of 5.9. Fruit were exposed to either a 2- or 5-day prestorage delay at 17 °C; or placed immediately into cold storage (control) at 0.5 °C. An additional treatment was CA storage at 2.5 °C. In February, occurrence of soft scald, soggy breakdown, and bitter pit were measured on 40 fruit per replication. Fruit were from `Honeycrisp'/M.26 trees planted in 1994. Treatments were replicated five times with four trees in each replication. Soft scald was very severe in this year, with 84% of control fruit being affected. Two-day prestorage delay reduced it to 48% and 5-day delay to 21%. Soggy breakdown was also severe with 14% of the fruit being affected. Two- and 5-day delays had no effect on occurrence of soggy breakdown, but CA storage increased it to 65%. Bitter pit was very rare and not affected by any of the treatments. These results demonstrate that in severe cases, shorter prestorage delay is not effective in preventing soft scald or soggy breakdown.

Harvest Date Effects on Maturity, Quality, and Storage Disorders of `Honeycrisp' Apples

`Honeycrisp' is a new apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] cultivar that has been planted extensively in North America, but the storage disorders soggy breakdown and soft scald have resulted in major fruit losses. The effects of harvest date and storage temperature on fruit quality and susceptibility of fruit to these disorders have been investigated in Michigan, New York, and Maine. Internal ethylene concentrations were variable over a wide range of harvest dates, and a rapid increase in autocatalytic ethylene production was not always apparent. The starch pattern index, soluble solids content, titratable acidity and firmness also appear to have limited use as harvest indices. Development of soggy breakdown and soft scald is associated with later harvest dates and storage of fruit at temperatures of 0 to 0.5 °C compared with higher storage temperatures. It is recommended that `Honeycrisp' be stored at 3 °C, although storage disorders still can occur at this temperature if fruit are harvested late. In addition, greasiness development may be worse at higher storage temperatures.

Cropload Affects Fruit Quality of Honeycrisp Apple

In 2001 and 2002, we imposed a wide range of croploads (0-15 fruits/cm2 of TCA) on 4- and 5-year-old Honeycrisp/M.9 trees by manual hand thinning soon after bloom to define appropriate croploads that give adequate repeat bloom and also the best fruit quality. At harvest each year we evaluated fruit ripening and quality. Samples were stored for 5 months in air at 38 °F and 33 °F and evaluated for fruit firmness and storage disorders. Cropload was negatively correlated with tree growth, return bloom, fruit size, fruit red color, fruit sugar content, fruit starch content, fruit firmness, fruit acidity, fruit bitter pit, fruit senescent breakdown, fruit rot and fruit superficial scald, but was positively correlated with leaf blotch symptoms, fruit internal ethylene concentration at harvest, and fruit soggy breakdown. There was a strong effect of cropload on fruit size up to a cropload 7, beyond which there was only a small additional effect. Although there was considerable variation in return bloom, a relatively low cropload was required to obtain adequate return bloom. Fruit red color was reduced only slightly up to a cropload of 8 beyond which it was reduced dramatically. The reduced fruit color and sugar content at high croploads could indicate a delay in maturity of but, fruits from high croploads were also softer, had less starch and greater internal ethylene. It that excessive croploads advance maturity. Overall, croploads greater than 10 resulted in no bloom the next year, and poor fruit size, color and flavor, but these fruits tended to have the least storage disorders. Moderate croploads (7-8) resulted in disappointing return bloom and mediocre fruit quality. For optimum quality and annual cropping, relatively low croploads of 4-5 were necessary.

Storage temperature, diphenylamine, and pre-storage delay effects on soft scald, soggy breakdown and bitter pit of ‘Honeycrisp’ apples

Abstract ‘Honeycrisp’ apple [( Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] fruit are susceptible to the storage disorders soggy breakdown, soft scald, and bitter pit. The effects of low and high temperature storage regimes (0 or 0.5 °C and 2.2, 2.8 or 3 °C, respectively), diphenylamine (DPA) treatment, and delays at 10 or 20 °C before storage, were investigated. Soggy breakdown and soft scald incidence is highest at the lowest temperatures of 0 or 0.5 °C and reduced or eliminated by storage at the higher temperatures. DPA sometimes reduced, but did not eliminate, soft scald. Both soggy breakdown and soft scald were markedly reduced or eliminated however, by keeping fruit at 10 or 20 °C before storage regardless of storage temperature. Bitter pit incidence was sometimes increased by delay treatments and storage at higher temperatures. Little effect of any treatment on firmness, soluble solids content, internal ethylene concentration (IEC), background color and titratable acidity was detected.