scholarly journals Mutation at β-Tubulin Codon 200 Indicated Thiabendazole Resistance in Penicillium digitatum Collected from California Citrus Packinghouses

Plant Disease ◽  
2006 ◽  
Vol 90 (6) ◽  
pp. 765-770 ◽  
Author(s):  
Leigh S. Schmidt ◽  
Jennifer M. Ghosoph ◽  
Dennis A. Margosan ◽  
Joseph L. Smilanick
Keyword(s):  
Point Mutation ◽  
Gene Sequence ◽  
Dna Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Citrus Fruit ◽  
Penicillium Digitatum ◽  
Resistant Isolate ◽  
Green Mold ◽  
Codon Positions ◽  
Β Tubulin

Thiabendazole (TBZ) is commonly applied to harvested citrus fruit in packinghouses to control citrus green mold, caused by Penicillium digitatum. Although TBZ is not used before harvest, another benzimidazole, thiophanate methyl, is commonly used in Florida and may be introduced soon in California to control postharvest decay of citrus fruit. Isolates from infected lemons and oranges were collected from many geographically diverse locations in California. Thirty-five isolates collected from commercial groves and residential trees were sensitive to TBZ, while 19 of 74 isolates collected from 10 packinghouses were resistant to TBZ. Random amplified polymorphic DNA analysis indicated that the isolates were genetically distinct and differed from each other. Nineteen TBZ-resistant isolates and a known TBZ-resistant isolate displayed a point mutation in the β-tubulin gene sequence corresponding to amino acid codon position 200. Thymine was replaced by adenine (TTC → TAC), which changed the phenylalanine (F) to tyrosine (Y). In contrast, for 49 TBZ-sensitive isolates that were sequenced, no mutations at this or any other codon positions were found. All of the isolates of P. digitatum resistant to TBZ collected from a geographically diverse sample of California packinghouses appeared to have the same point mutation conferring thiabendazole resistance.

scholarly journals Influence of pH and NaHCO3 on Effectiveness of Imazalil to Inhibit Germination of Penicillium digitatum and to Control Postharvest Green Mold on Citrus Fruit

Plant Disease ◽  
2005 ◽  
Vol 89 (6) ◽  
pp. 640-648 ◽  
Author(s):  
J. L. Smilanick ◽  
M. F. Mansour ◽  
D. A. Margosan ◽  
F. Mlikota Gabler ◽  
W. R. Goodwine
Keyword(s):  
Citrus Fruit ◽  
Penicillium Digitatum ◽  
Resistant Isolate ◽  
Potato Dextrose Broth ◽  
Lemon Fruit ◽  
Green Mold ◽  
Sensitive Isolate ◽  
Residue Levels ◽  
Influence Of Ph

In vitro, spores of Penicillium digitatum germinated without inhibition between pH 4 and 7, but were inhibited at higher pH. Estimated concentrations of imazalil (IMZ) in potato-dextrose broth-Tris that caused 50% reduction in the germination of spores (ED50) of an IMZ-sensitive isolate M6R at pH 4, 5, 6, and 7 were 0.16, 0.11, 0.015, and 0.006 μg/ml, respectively. ED50 IMZ concentrations of an IMZ-resistant isolate D201 at pH 4, 5, 6, and 7 were 5.9, 1.4, 0.26, and 0.07 μg/ml, respectively. The natural pH within 2-mm-deep wounds on lemon was 5.6 to 5.1 and decreased with fruit age. IMZ effectiveness to control green mold and its residues increased with pH. The pH in wounds on lemon fruit 24 h after immersion in 1, 2, or 3% NaHCO3 increased from pH 5.3 to 6.0, 6.3, and 6.7, respectively. NaHCO3 dramatically improved IMZ performance. Green mold incidence among lemon fruit inoculated with M6R and treated 24 h later with IMZ at 10 μg/ml, 1% NaHCO3, or their combination was 92, 55, and 22%, respectively. Green mold among lemon fruit inoculated with D201 and treated 24 h later with water, IMZ at 500 μg/ml, 3% NaHCO3, or their combination was 96.3, 63.0, 44.4, and 6.5%, respectively. NaHCO3 did not influence IMZ fruit residue levels.

scholarly journals Pre- and Postharvest Treatments to Control Green Mold of Citrus Fruit During Ethylene Degreening

Plant Disease ◽  
2006 ◽  
Vol 90 (1) ◽  
pp. 89-96 ◽  
Author(s):  
J. L. Smilanick ◽  
M. F. Mansour ◽  
D. Sorenson
Keyword(s):  
Sodium Bicarbonate ◽  
Color Change ◽  
Citrus Fruit ◽  
Penicillium Digitatum ◽  
Color Removal ◽  
Thiophanate Methyl ◽  
Green Color ◽  
Green Mold ◽  
Orange Fruit ◽  
High Level

Two approaches, fungicide applications to trees before harvest and drenching fruit after harvest, were evaluated to minimize postharvest green mold, caused by Penicillium digitatum, particularly among fruit subjected to ethylene gas after harvest, a practice termed “degreening” that eliminates green rind color. Preharvest applications of thiophanate methyl (TM) controlled postharvest green mold consistently. In five tests, green mold among degreened orange fruit was 16% when TM was applied 1 week before harvest; whereas, among fruit not treated, the incidence was 89.5%. Thiabendazole (TBZ) applied to harvested fruit in bins before degreening also was very effective. TBZ effectiveness was enhanced by mild heating (41°C), adding sodium bicarbonate, and immersing fruit, rather than drenching them, with the solution. With these measures, an isolate of P. digitatum with a high level of TBZ resistance was significantly controlled. In semicommercial tests with naturally inoculated fruit, TBZ and sodium bicarbonate treatment reduced green mold incidence from 11% among untreated orange fruit to 2%. TBZ residues in lemon fruit at 41°C were about twice those treated at 24°C. Neither TM before harvest nor TBZ and sodium bicarbonate applied after harvest influenced green color removal during degreening of orange fruit. Sodium bicarbonate slightly reduced the rate of lemon color change.

scholarly journals Effects of Curing on Green Mold and Stem-End Rot of Citrus Fruit and Its Potential Application Under Florida Packing System

Plant Disease ◽  
2005 ◽  
Vol 89 (8) ◽  
pp. 834-840 ◽  
Author(s):  
Jiuxu Zhang ◽  
Patricia P. Swingle
Keyword(s):  
Potential Application ◽  
Mycelial Growth ◽  
Citrus Fruit ◽  
Penicillium Digitatum ◽  
Curing Time ◽  
Lasiodiplodia Theobromae ◽  
Green Mold ◽  
Florida Citrus ◽  
The Impact ◽  
Packing System

The potential of citrus fruit curing for the control of green mold caused by Penicillium digitatum, and the impact of this treatment on stem-end rot caused by Lasiodiplodia theobromae were investigated. The optimum temperatures for mycelial growth of P. digitatum and L. theobromae were about 25 and 30°C, respectively. P. digitatum did not grow at 35°C, while L. theobromae did. Injuries of ‘Valencia’ oranges developed less green mold disease at 30 and 35°C than at 25°C or lower. Green mold incidences on ‘Valencia’ oranges treated at 21°C (uncured control), 30 and 35°C for 48 h were 51, 17.4, and 0%, respectively, for inoculated fruit, and 18.8, 11.4, and 0%, respectively, for wounded fruit after 2 weeks of storage at 21°C. However, a significant increase in stem-end rot occurred at 35°C when compared with 21°C (uncured control). In two of three different tests, curing fruit at 35°C for 48 h achieved better green mold control than a shorter curing time of 24 h. Curing ‘Pineapple’ oranges showed a similar or better efficacy for green mold control than imazalil at 500 and 1,000 ppm applied by either dip or packingline drip. The combination of thiabendazole drench (500 ppm) and curing of wounded ‘Valencia’ oranges and inoculated ‘Flame’ grapefruit reduced both green mold and stem-end rot by more than 93%. This study suggests that curing (35°C for 48 h) could be integrated into the current Florida citrus packing system to effectively control postharvest decays.

scholarly journals The Antifungal Potential of Sarvacrol against Penicillium digitatum through 1H-NMR Based Metabolomics Approach

2019 ◽  
Author(s):  
Chunpeng Wan ◽  
Yuting Shen ◽  
Muhammad Farrukh Nisar ◽  
Wenwen Qi ◽  
Chuying Chen ◽  
...  
Keyword(s):  
1H Nmr ◽  
Citrus Fruit ◽  
Metabolic Changes ◽  
Penicillium Digitatum ◽  
Glutathione Metabolism ◽  
Strong Positive Correlation ◽  
Food Preservative ◽  
Metabolomic Profiling ◽  
Green Mold ◽  
Antifungal Potential

Carvacrol has long been studied for its natural antifungal potential and food preservative. But the exact mode of its action remained highly complex as a general, but especially for Penicillium digitatum (P. digitatum) largely remained unexplored. Herein, a 1H-NMR-based metabolomic technique was used to investigate the antifungal mechanism of carvacrol. The metabolomic profiling data showed that alanine, aspartate, glutamate and glutathione metabolism were imbalanced in the fungal hyphae. A strong positive correlation was seen between aspartate, glutamate, alanine and glutamine, while negative correlation among glutathione and lactate. These metabolic changes revealed that carvacrol-induced oxidative stress had disturbed the energy production and amino acid metabolism of P. digitatum. Current study will improve the understanding of the metabolic changes posed by plant-based fungicides in order to control citrus fruit green mold caused by P. digitatum. Moreover, the study will provided certain experimental and theoretical basis for the development of novel citrus fruit preservatives.

scholarly journals Light: An Alternative Method for Physical Control of Postharvest Rotting Caused by Fungi of Citrus Fruit

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
İbrahim Kahramanoğlu ◽  
Muhammad Farrukh Nisar ◽  
Chuying Chen ◽  
Serhat Usanmaz ◽  
Jinyin Chen ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Light Exposure ◽  
Citrus Fruit ◽  
Penicillium Digitatum ◽  
Solar Light ◽  
Special Focus ◽  
Penicillium Italicum ◽  
Blue Mold ◽  
Health Concerns ◽  
Green Mold

Solar light has fundamental roles in vast chemical, biochemical, and physical process in biosphere and hence been declared as “source of life.” Solar light is further classified into a broad range of electromagnetic waves, and each region in the solar spectrum bears its unique actions in the universe or biosphere. Since centuries, solar light is believed as a potent source of killing pathogens causing postharvest losses on food products as well as human skin diseases. Citrus fruit crops are widely produced and consumed across the world, but due to their higher juicy contents, Penicillium italicum (blue mold) and Penicillium digitatum (green mold) make their entry to decay fruits and cause approximately 80% and 30% fruit losses, respectively. Agrochemicals or synthetic fungicides are highly efficient to control these postharvest fungal pathogens but have certain health concerns due to toxic environmental residues. Therefore, the scientific community is ever looking for some physical ways to eradicate such postharvest fungal pathogens and reduce the yield losses along with maintaining the public health concerns. This review article presents and discusses existing available information about the positive and negative impacts of different spectrums of solar light exposure on the postharvest storage of citrus fruits, especially to check citrus postharvest rotting caused by Penicillium italicum (blue mold) and Penicillium digitatum (green mold). Moreover, a special focus shall be paid to blue light (390–500 nm), which efficiently reduces the decay of fruits, while keeping the host tissues/cells healthy with no known cytotoxicity, killing the fungal pathogen probably by ferroptosis, but indepth knowledge is scanty. The study defines how to develop commercial applications of light in the postharvest citrus industry.

scholarly journals Synthesis and Antifungal Activities of Cinnamaldehyde Derivatives against Penicillium digitatum Causing Citrus Green Mold

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Zengyu Gan ◽  
Jianping Huang ◽  
Jinyin Chen ◽  
Muhammad Farrukh Nisar ◽  
Wenwen Qi
Keyword(s):  
Reducing Sugars ◽  
Citrus Fruit ◽  
Pathogenic Fungi ◽  
Penicillium Digitatum ◽  
Economic Losses ◽  
Fungal Cell ◽  
Green Mold ◽  
Antifungal Potential ◽  
Germination And Growth ◽  
Derivatives Of

Penicillium digitatum (green mold) is pathogenic fungi and causes citrus fruit postharvest rotting that leads to huge economic losses across the world. The current study was aimed to develop a new derivative of cinnamaldehyde (4-methoxycinnamaldehyde) through the cross-hydroxyaldehyde condensation method with benzaldehyde substituted by a benzene ring under the catalysis of alkaline reagent and, moreover, to test their antifungal potential against P. digitatum, the major citrus fruit rotting fungi. Multiple derivatives of cinnamaldehyde viz. 4-nitro CA, 4-chloro CA, 4-bromo CA, 4-methyl CA, 4-methoxy CA, and 2,4-dimethoxy CA were synthesized in the current study whereas the 4-methoxy CA showed highest antifungal actions for citrus fruit postharvest rotting fungi P. digitatum. Moreover, 4-methoxy CA was found to reduce the spore germination and growth by damaging the fungal cell membrane, as well as declined the levels of reducing sugars.

scholarly journals The Antifungal Potential of Carvacrol against Penicillium Digitatum through 1H-NMR Based Metabolomics Approach

2019 ◽  
Vol 9 (11) ◽  
pp. 2240 ◽  
Author(s):  
Chunpeng Wan ◽  
Yuting Shen ◽  
Muhammad Farrukh Nisar ◽  
Wenwen Qi ◽  
Chuying Chen ◽  
...  
Keyword(s):  
1H Nmr ◽  
Citrus Fruit ◽  
Volatile Oil ◽  
Metabolic Changes ◽  
Penicillium Digitatum ◽  
Glutathione Metabolism ◽  
Strong Positive Correlation ◽  
Metabolomic Profiling ◽  
Green Mold ◽  
Antifungal Potential

Carvacrol (5-Isopropyl-2-methylphenol), a volatile oil constituent, mainly exists in Labiaceae family plants. Carvacrol has long been studied for its natural antifungal potential and food preservative potential. However, its exact mode of action, especially against Penicillium digitatum (P. digitatum), remains unexplored. Herein, a 1H-NMR-based metabolomic technique was used to investigate the antifungal mechanism of carvacrol against P. digitatum. The metabolomic profiling data showed that alanine, aspartate, glutamate, and glutathione metabolism were imbalanced in the fungal hyphae. A strong positive correlation was seen between aspartate, glutamate, alanine, and glutamine, with a negative correlation among glutathione and lactate. These metabolic changes revealed that carvacrol-induced oxidative stress had disturbed the energy production and amino acid metabolism of P. digitatum. The current study will improve the understanding of the metabolic changes posed by plant-based fungicides in order to control citrus fruit green mold caused by P. digitatum. Moreover, the study will provide a certain experimental and theoretical basis for the development of novel citrus fruit preservatives.

scholarly journals Improved Control of Green Mold of Citrus with Imazalil in Warm Water Compared with Its Use in Wax

Plant Disease ◽  
1997 ◽  
Vol 81 (11) ◽  
pp. 1299-1304 ◽  
Author(s):  
J. L. Smilanick ◽  
I. F. Michael ◽  
M. F. Mansour ◽  
B. E. Mackey ◽  
D. A. Margosan ◽  
...  
Keyword(s):  
Citrus Fruit ◽  
The United States ◽  
Resistant Isolate ◽  
Solution Temperature ◽  
Ambient Temperatures ◽  
Commercial Practice ◽  
Green Mold ◽  
Fungicide Residues ◽  
Mode Of Application ◽  
The U.S

The effectiveness of imazalil for the control of citrus green mold (caused by Penicillium digitatum) improved significantly when fruit were treated with heated aqueous solutions of the fungicide as compared with the current commercial practice of spraying wax containing imazalil on fruit. When applied at less than 500 μg·ml-1 in solutions heated to 37.8°C, control of postharvest green mold of citrus was significantly superior to applications of 4,200 μg·ml-1 imazalil in wax sprayed on fruit at ambient temperatures. The improvement in imazalil efficacy was obtained with a decrease in fungicide residues on the fruit. Residues of about 3.5 μg·g-1 imazalil deposited by the application of imazalil in wax reduced the incidence of green mold on lemons from 94.4% among untreated controls to 15.1%, whereas an equal residue deposited by passing fruit through heated aqueous imazalil reduced green mold incidence to 1.3%. Similar differences were found in tests with oranges. Residues of 2 and 3.5 μg·g-1 imazalil were needed to control the sporulation of P. digitatum on oranges and lemons, respectively. The mode of application of imazalil did not influence control of sporulation. The influence of immersion time, imazalil concentration, and solution temperature on imazalil residues on oranges and lemons was determined in tests using commercial packing equipment, and a model that describes residue deposition was developed. Residues after a 30- or 60-s treatment in heated aqueous imazalil were sufficient to control sporulation, but residues after 15-s treatments were too low and required an additional application of 1,070 μg·ml-1 imazalil in wax to deposit an amount of imazalil sufficient to control sporulation. An imazalil-resistant isolate of P. digitatum was significantly controlled by heated aqueous imazalil. The incidence of green mold of navel oranges was reduced from 98.8 to 17.4% by treatment in 410 μg·ml-1 imazalil at 40.6°C for 90 s. However, control of the resistant isolate required imazalil residues on the fruit of 7.9 μg·g-1, which is within the U.S. tolerance of 10 μg·g-1 but above the 5 μg·g-1 tolerance of some countries that import citrus fruit from the United States.

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