Components of Apple Fruit Epicuticular Wax and Growth of Sooty Blotch Disease

Sooty blotch severity varied among: `Smoothie Golden Delicious', `Coop-17', `Liberty', `NY65707-19', and `NY61356-22', apple cultivars surveyed In this study, Peltaster fructicola Johnson, Sutton et Hodges, and Leptodontidium elatius (F. Mangenot) Hoog were grown on compounds that make up the epicuticular wax of the fruit in order to determine if one or more wax compound acted as a substrate for growth, or if a growth modifier could be identified. There were no relationships between the major epicuticular wax components of each cultivar and the severity of the disease. P. fructicola and L. elatius, two of the most important sooty blotch fungi, did not grow on any of the five major components of the epicuticular wax. SEM studies showed that mycelia of P. fructicola grew on the surface of the wax and did not appear to degrade it. In view of the fact that conidia germination requires pre-treatment with dilute apple juice and the fact that SB does not grow on fruit cuticles where russet creates an impermeable layer. We conclude that the SB fungi are epiphytic and obtain their nutrients primarily from fruit leachates and not from components of the cuticle.

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Relationship Between Apple Fruit Epicuticular Wax and Growth of Peltaster fructicola and Leptodontidium elatius, Two Fungi that Cause Sooty Blotch Disease

Plant Disease ◽

10.1094/pdis.2000.84.7.767 ◽

2000 ◽

Vol 84 (7) ◽

pp. 767-772 ◽

Cited By ~ 47

Author(s):

Robert D. Belding ◽

Turner B. Sutton ◽

Sylvia M. Blankenship ◽

Eric Young

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Mycelial Growth ◽

Apple Juice ◽

Apple Fruit ◽

Epicuticular Wax ◽

Epicuticular Waxes ◽

Sooty Blotch ◽

Apple Cultivars ◽

Scanning Electron

Sooty blotch severity varied among apple cultivars or selections surveyed in 1989 and 1992. No mycelial growth was observed on russetted areas of the cuticle that are considered impermeable. Ursolic acid and n-alkanes were the most prominent components of the epicuticular waxes of the cultivars or selections evaluated. Although there were differences in the relative proportions of these compounds among the cultivars, the differences were not related to the severity of sooty blotch. Peltaster fructicola and Leptodontidium elatius were grown on compounds that comprise the epicuticular wax of the fruit to determine if one or more of these were needed for growth. The fungi did not grow on any of the five major components of the epicuticular wax unless dilute apple juice was included. Scanning electron microscopy studies showed that mycelia of P. fructicola grew on the surface of the wax and did not appear to degrade it. Our studies support the hypothesis that P. fructicola and L. elatius fungi are epiphytes and obtain their nutrients not from components of the cuticle, but more likely from fruit leachates.

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176 Substrate on Apple Fruit Increased Sooty Blotch Incidence

HortScience ◽

10.21273/hortsci.35.3.421a ◽

2000 ◽

Vol 35 (3) ◽

pp. 421A-421

Author(s):

Robert D. Belding

Keyword(s):

Apple Juice ◽

Apple Fruit ◽

Insect Damage ◽

Potential Mechanism ◽

Skin Texture ◽

Breeding Stock ◽

Sooty Mold ◽

Sooty Blotch ◽

Disease Resistant ◽

Drought Conditions

The potential mechanism of susceptibility of apple (Malus ×domestica Borkh.) fruit to sooty blotch due to carbohydrate leachates was examined. Fruit received applications of 0.5% apple juice to the fruit cuticle in order to mimic leachates. Nine cultivars of apple were selected from a variety block of potentially disease resistant breeding stock. Intact fruit on selected limbs received 0.5% apple juice applications on eight evenly spaced occasions during development. Trees received a minimal fungicide program only. Leachate samples from the fruit cuticles were collected monthly by immersion of whole, detached fruit in dH2O for 60 min. At harvest, fruit were evaluated for skin roughness, fruit rots, sooty blotch, sooty mold, flyspeck, and insect injury. Despite drought conditions, sooty blotch and sooty mold showed strong increases in disease intensity ratings, while flyspeck and skin texture damage showed moderate increases in intensity due to the dilute juice applications. Fruit rots and insect damage were unaffected by the juice applications.

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Postharvest Fruit Rots of Apple in Greece: Pathogen Incidence and Relationships Between Fruit Quality Parameters, Cultivar Susceptibility, and Patulin Production

Plant Disease ◽

10.1094/pdis-11-10-0856 ◽

2011 ◽

Vol 95 (6) ◽

pp. 666-672 ◽

Cited By ~ 33

Author(s):

S. Konstantinou ◽

G. S. Karaoglanidis ◽

G. A. Bardas ◽

I. S. Minas ◽

E. Doukas ◽

...

Keyword(s):

Botrytis Cinerea ◽

Gray Mold ◽

Apple Fruit ◽

Phenol Concentration ◽

Fruit Rot ◽

Minor Importance ◽

Blue Mold ◽

Mycotoxin Contamination ◽

Golden Delicious ◽

Apple Cultivars

The incidence of pathogens associated with postharvest fruit rots on the four most extensively cultivated apple cultivars (Red Delicious, Golden Delicious, Granny Smith, and Fuji) in Greece was surveyed during two consecutive storage periods (2008–09 and 2009–10) in five packinghouses located in northern Greece. The fungi isolated were identified based on their morphological characteristics and internal transcribed spacer gene sequencing. In the four cultivars sampled, Penicillium expansum and Botrytis cinerea were the predominant pathogens, accounting for averages of 44.2 and 23.6%, respectively, of the pathogens isolated from the sampled fruit. Two other important rot pathogens were Alternaria tenuissima and Mucor pyriformis, accounting for 16.1 and 6.6%, respectively, of the diseased apple fruit. Other pathogens such as Monilinia laxa, M. fructigena, Botryosphaeria obtusa, Geotrichum candidum, Fusarium avenaceum, and F. proliferatum were isolated at low frequencies and are considered of minor importance. Measurements of the resistance level of the four apple cultivars to fruit rot caused by P. expansum and Botrytis cinerea revealed that Golden Delicious was the most susceptible to blue mold while Fuji was the most susceptible to gray mold infections. Susceptibility to gray mold was negatively correlated with flavonoid and phenol concentration as well to fruit antioxidant activity, while susceptibility to blue mold was negatively correlated with fruit firmness and phenol concentration. Patulin production was significantly higher in Red Delicious and Golden Delicious fruit than in Granny Smith and Fuji fruit and was negatively correlated with the acidity of the fruit. The high incidence of P. expansum and A. tenuissima along with the presence of F. avenaceum and F. proliferatum, all of which are potentially mycotoxin producers, emphasize the risk for mycotoxin contamination of apple fruit juices and by-products. Furthermore, information on the distribution of the pathogens on the main cultivars may be useful for the implementation of strategies to control the diseases and minimize the threat of mycotoxin contamination on each cultivar.

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Scald-related Volatiles in the Epicuticular Wax of Apple Fruit

HortScience ◽

10.21273/hortsci.32.3.536a ◽

1997 ◽

Vol 32 (3) ◽

pp. 536A-536

Author(s):

S. Wee ◽

R.M. Beaudry

Keyword(s):

Gas Chromatography ◽

Volatile Compounds ◽

Inverse Relationship ◽

Apple Fruit ◽

Epicuticular Wax ◽

Epicuticular Waxes ◽

Conjugated Trienes ◽

Apple Cultivars ◽

Gas Chromatography Mass Spectroscopy ◽

Fruit Surface

Volatile compounds produced by apple (Malus domestica Borkh) fruit partition into the cuticle and epicuticular waxes and may play an important role in superficial apple scald. Of these volatiles, α-farnesene, conjugated trienes, hydroperoxides, and 6-methyl-5-hepten-2-one have been identified as playing a crucial role in scald production. Volatiles from the epicuticular wax of four different apple cultivars have been analyzed by gas chromatography/mass spectroscopy. A correlation was found between scald incidence and 6-methyl-5-hepten-2-one content and the 6-methyl-5-hepten-2-one:α-farnesene ratio. α-Farnesene is the most-abundant volatile at the beginning of storage, whereas 6-methyl-5-hepten-2-one is present in minute quantities. These two volatile compounds appear to have an inverse relationship with respect to one another since the levels of 6-methyl-5-hepten-2-one increased and α-farnesene decreased prior to the onset of apple scald. This changing ratio may have been due to an autoxidative process resulting in the breakdown of α-farnesene to 6-methyl-5-hepten-2-one. Analysis of the volatiles emanating from the apple wax revealed a number of compounds associated with aroma that also partition readily into the fruit surface.

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Performance of Nine Apple Cultivars Grown with Six Fungicide Regimes

HortScience ◽

10.21273/hortsci.31.4.675e ◽

1996 ◽

Vol 31 (4) ◽

pp. 675e-675

Author(s):

Richard Marini ◽

John Barden ◽

Donald Sowers

Keyword(s):

Late Summer ◽

Leaf Abscission ◽

Disease Symptoms ◽

Early Season ◽

Late Season ◽

Sooty Blotch ◽

Golden Delicious ◽

Root Stock ◽

Apple Cultivars ◽

Early Leaf Abscission

In 1993 a factorial experiment, involving nine apple cultivars on M.9 root-stock and six fungicide regimes, was established. The cultivars included `Delicious', `Golden Delicious', `York Imperial', `Redfree', `Freedom', `Liberty', NY 74828-12, NY 73334-35, and NY 74840-1. The fungicide treatments included earlyseason sprays of Bayleton or Dodine, separately or combined, and late-season sprays of Captan plus Benomyl alone or combined with early-season sprays of Bayleton plus Dodine. Non-sprayed trees served as a control. In 1995 leaves and fruits were evaluated for disease symptoms. Leaf spot (symptoms caused by black rot or alternaria leaf blotch) was most severe on `Redfree' and NY 73334-35, and least severe on `Delicious', `Golden Delicious', and `York'. By late summer NY 74828-12 had the most leaf abscission, whereas NY 74840-1, `Liberty', and `Delicious' lost the fewest leaves. Early-season fungicide sprays did not reduce early leaf abscission. Sooty blotch and fly speck, but not rots, were nearly eliminated by late-season applications of Captan plus Benomyl. Averaged over all fungicide treatments, more than half of the fruits from `Delicious', `Redfree', and NY 74828-12 were free of disease symptoms. Cultivars with <25% of the fruits without infection included `York', `Liberty', NY 74840-1 and NY 73334-35. `York' and `Redfree' had >25% of the fruits with rots, while all other cultivars had <9% fruits with rots. `Delicious' and NY 73334-35 had the fewest rotten fruits. Rots were not controlled by any fungicide treatment. `Liberty' and NY 73334-35 had the most flyspeck and `Redfree' had the least. `Liberty', NY 74840-1 and NY 73334-35 had the most sooty blotch and `Redfree' and NY 74828-12 had the least.

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Effects of 1-Methylcyclopropene on Firmness Loss and the Development of Rots in Apple Fruit Kept in Farm Markets or at Elevated Temperatures

HortTechnology ◽

10.21273/horttech.21.4.494 ◽

2011 ◽

Vol 21 (4) ◽

pp. 494-499 ◽

Cited By ~ 6

Author(s):

Steven McArtney ◽

Michael Parker ◽

John Obermiller ◽

Tom Hoyt

Keyword(s):

United States ◽

Shelf Life ◽

High Temperatures ◽

Malus Domestica ◽

Elevated Temperatures ◽

Southeastern United States ◽

Apple Fruit ◽

Golden Delicious ◽

Apple Cultivars ◽

Farm Market

Many of the apples (Malus ×domestica) grown in the southeastern United States are sold to consumers through direct farm markets and roadside stands. Fruit in these markets may be exposed to high temperatures (>68 °F), which cause the fruit to ripen quickly, limiting their shelf life and consumer appeal and increasing their susceptibility to decay pathogens. Studies were undertaken in 2009 and 2010 to determine the effects of a 1-μL·L−1 postharvest 1-methylcyclopropene (1-MCP) treatment on the maintenance of flesh firmness and the incidence of rots in fruit held at elevated temperatures for up to 8 weeks. 1-MCP-treated fruit of three apple cultivars (Ginger Gold, Gala, and Golden Delicious) held in three retail farm markets in the southeastern United States maintained their firmness for 3 to 5 weeks. The firmness of non-treated ‘Ginger Gold’ fruit declined to less than 12 lbf after 1 week in each market, whereas the firmness of treated fruit remained greater than 16 lbf after 3 weeks. Treated ‘Gala’ fruit maintained their firmness at 14 lbf during 4 weeks in each farm market, whereas the firmness of non-treated fruit declined to less than 12 lbf after 2 weeks. The firmness of non-treated ‘Golden Delicious’ fruit declined to less than 12 lbf after 1 week in each farm market, whereas treated fruit maintained their firmness for up to 4 weeks. ‘Golden Delicious’ fruit treated with 1-MCP exhibited almost no loss of firmness during 4 weeks at 32, 50, or 70 °F, or even up to 8 weeks at 32 or 50 °F. The incidence of fruit rots increased with temperature, and 1-MCP reduced the incidence of fruit rots after 4 weeks at 70 °F in 2009 or after 8 weeks at 70 °F in 2010. These data show that 1-MCP may be of great benefit to producers who sell their fruit directly to the consumer by delaying the loss in firmness and reducing the incidence of rots in fruit kept at elevated temperatures.

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First Report of Seven Species of Sooty Blotch and Flyspeck Fungi on Asimina triloba in Iowa

Plant Disease ◽

10.1094/pdis-92-9-1366c ◽

2008 ◽

Vol 92 (9) ◽

pp. 1366-1366 ◽

Cited By ~ 5

Author(s):

K. Hemnani ◽

P. J. O'Malley ◽

B. Tanović ◽

J. C. Batzer ◽

M. L. Gleason

Keyword(s):

North America ◽

Host Plants ◽

Apple Fruit ◽

Epicuticular Wax ◽

Reservoir Host ◽

Asimina Triloba ◽

Sooty Blotch ◽

Sooty Blotch And Flyspeck ◽

Epicuticular Wax Layer

Fungi in the sooty blotch and flyspeck (SBFS) complex cause major economic losses on cultivated pome fruits in humid regions worldwide and also colonize many species of reservoir host plants. In 2007, 10 mature fruit of pawpaw (Asimina triloba), a native tree in eastern North America exhibiting SBFS colonies on the epicuticular wax layer, were collected from wild trees in eastern Iowa. Colonies of SBFS fungi on the fruit were described according to mycelial type (1). Isolates of representative colonies on acidified water agar were subcultured on potato dextrose agar and the morphological characters were observed. After DNA was extracted from cultures and amplified by PCR using primer set ITS-1F/ITS4, 470-bp sequences were compared with those of previously identified SBFS species using NCBI BLAST. The BLAST analysis showed 100% homology of the sequences with six species that had been previously confirmed to cause SBFS on apple fruit by fulfilling Koch's postulates (1): Colletogloeum sp. FG2, Dissoconium aciculare, Peltaster sp. P2.1, P. fructicola, Stomiopeltis versicola, and Stomiopeltis sp. RS1 (GenBank Accession Nos. AY598907, AY598874, AY5988888, AY598887, AY5160165, and AY598882, respectively). Using the NCBI bl2seq application, Dothideomycete sp. CS2, an additional previously confirmed SBFS species, was revealed by sequence homology. Morphology of some SBFS species on pawpaw differed from that on apple. For example, Colletogloeum sp. FG2, which produces the fuliginous mycelial type (1) on apple fruit, developed the ridged honeycomb mycelial type on pawpaw fruit. D. aciculare and Stomiopeltis sp. RS1 produced the compact speck mycelial type on pawpaw, but are known to develop discrete speck and ramose mycelial types, respectively, on apple. These differences may result from host species differences in the epicuticular wax layer of the fruit. To our knowledge, this is the first report of SBFS fungi on A. triloba in North America, although the SBFS species Zygophiala jamaicensis was reported on the same host in Japan (2). Identifying SBFS fungi on reservoir host plants is an important step toward improving disease management strategies. References: (1) J. Batzer et al. Mycologia 97:1268, 2005. (2) H. Nasu and H. Kunoh Plant Dis. 71:361, 1987.

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APPLE FRUIT CUTICULAR WAX INFLUENCE ON FLYSPECK, SOOTY BLOTCH, AND RUSSETING

HortScience ◽

10.21273/hortsci.25.9.1110d ◽

1990 ◽

Vol 25 (9) ◽

pp. 1110d-1110

Author(s):

Robert D. Belding ◽

Eric Young

Keyword(s):

Unit Area ◽

Compositional Analysis ◽

Apple Fruit ◽

Cuticular Wax ◽

Pure Gold ◽

Apple Trees ◽

Sooty Blotch ◽

Golden Delicious ◽

Mature Apple

Fruit from six cultivars of mature apple trees were evaluated for cuticular wax characteristics. Incidence of flyspeck, sooty blotch and russet was compared to the wax component of the cuticle. Three cultivars of Golden Delicious: Sundale Spur, Pure Gold, and Lys Golden; and three cultivars of Red Delicious: Starkspur Supreme, Oregon I, and Starkrimson, were examined.Incidence of flyspeck on Golden Delicious apples was negatively correlated to cuticular wax per unit area. Sooty blotch appearance was greater on Golden Delicious fruit as compared to Red Delicious. Incidence of sooty blotch was positively correlated to cuticular wax weight per unit area among the cultivars of Red Delicious. Russeting was negatively correlated to wax weight per unit area for the Red Delicious cultivars. Wax compositional analysis will also be discussed.

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Optimization of In Vitro Regeneration from Leaf Explants of Apple Cultivars Golden Delicious and Melrose

HortScience ◽

10.21273/hortsci.47.8.1117 ◽

2012 ◽

Vol 47 (8) ◽

pp. 1117-1122 ◽

Cited By ~ 6

Author(s):

Nevena Mitić ◽

Mariana Stanišić ◽

Jelena Milojević ◽

Ljiljana Tubić ◽

Tatjana Ćosić ◽

...

Keyword(s):

In Vitro Regeneration ◽

Leaf Explants ◽

Shoot Multiplication ◽

Gelling Agent ◽

Regeneration Medium ◽

Regeneration Frequency ◽

Golden Delicious ◽

Apple Cultivars ◽

Pre Treatment

An efficient in vitro shoot regeneration method from leaf explants of apple cultivars Golden Delicious and Melrose by optimization of regeneration medium, explant type and orientation, dark pre-treatment, and gelling agent is presented. Murashige and Skoog’s regeneration medium containing 22 μM thidiazuron (TDZ) and 1.5 μM indole-3-butyric acid (IBA) (M2 medium) was superior for regeneration as well as for subsequent shoot multiplication in both cultivars, providing regeneration frequency of 95% or higher in the best combination with other factors. Pre-incubation in the dark proved to be an essential factor for regeneration. The use of agar as a gelling agent provides satisfactory regeneration frequency compared with media gelled with PhytagelTM. Leaf explants of cv. Melrose with adaxial surface in contact with M2 medium and those of cv. Golden Delicious orientated contrary regenerated the highest mean number of shoots per explant. Under optimal conditions, a maximal index of shoot-forming capacity of 11.44 and 6.30 for ‘Melrose’ and ‘Golden Delicious’, respectively, was achieved. Regenerated shoots were successfully rooted and acclimated ex vitro.

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Variation of Phytochemicals Content in Pulp and Skin of Seven Romanian Apple Cultivars

Revista de Chimie ◽

10.37358/rc.17.3.5481 ◽

2017 ◽

Vol 68 (3) ◽

pp. 474-477

Author(s):

Lacramioara Oprica ◽

Doina Atofanei ◽

Vladimir Poroch

Keyword(s):

Antioxidant Activity ◽

Ascorbic Acid ◽

Anthocyanin Content ◽

Colour Intensity ◽

Total Polyphenol ◽

Valuable Source ◽

Golden Delicious ◽

Apple Cultivars ◽

Apple Fruits

The amounts of anthocyanins, flavonoids, total polyphenol and ascorbic acid in seven apple cultivars from Romania were investigated. The amounts of polyphenol and flavonoids in pulp and skin of apple cultivars ranged between 17.18�7.52 mg GAE/g DW and 20.10�11.06 mg CE/g DW as well as 3.64�1.18 mg GAE/g DW and 10.31�5.57 mg CE/g DW, respectively. The highest and smallest values of ascorbic acid both in the skin and the pulp were observed in the cultivars Mutsu and Starkrimson. The anthocyanin content is positively correlated with the colour intensity of the apple epicarp, being about three-fold higher in Prima than Golden Delicious cultivar. The better antioxidant activity provided by the content of polyphenol, ascorbic acid and flavonoids was in apple fruits of Mutsu cultivar and for this reason it should be regarded as a valuable source of antioxidants.

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