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 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 High Incidence of Preharvest Colonization of Huanglongbing-Symptomatic Citrus sinensis Fruit by Lasiodiplodia theobromae (Diplodia natalensis) and Exacerbation of Postharvest Fruit Decay by That Fungus

2014 ◽  
Vol 81 (1) ◽  
pp. 364-372 ◽  
Author(s):  
Wei Zhao ◽  
Jinhe Bai ◽  
Greg McCollum ◽  
Elizabeth Baldwin
Keyword(s):  
Hydrolytic Enzymes ◽  
Citrus Fruit ◽  
Decay Rates ◽  
Causal Organism ◽  
Lasiodiplodia Theobromae ◽  
Content Type ◽  
Surface Sterilization ◽  
Fruit Drop ◽  
Liberibacter Asiaticus ◽  
The Impact

ABSTRACTHuanglongbing (HLB), presumably caused by the bacterium “CandidatusLiberibacter asiaticus,” is a devastating citrus disease associated with excessive preharvest fruit drop.Lasiodiplodia theobromae(diplodia) is the causal organism of citrus stem end rot (SER). The pathogen infects citrus fruit under the calyx abscission zone (AZ-C) and is associated with cell wall hydrolytic enzymes similar to plant enzymes involved in abscission. By means of DNA sequencing, diplodia was found in “Ca. Liberibacter asiaticus”-positive juice from HLB-symptomatic fruit (S) but not in “Ca. Liberibacter asiaticus”-negative juice. Therefore, the incidence of diplodia in fruit tissues, the impact on HLB-related postharvest decay, and the implications for HLB-related preharvest fruit drop were investigated in Hamlin and Valencia oranges. Quantitative PCR results (qPCR) revealed a significantly (P< 0.001) greater incidence of diplodia in the AZ-C of HLB-symptomatic (S; “Ca. Liberibacter asiaticus” threshold cycle [CT] of <30) than in the AZ-C of in asymptomatic (AS; “Ca. Liberibacter asiaticus”CTof ≥30) fruit. In agreement with the qPCR results, 2 weeks after exposure to ethylene, the incidences of SER in S fruit were 66.7% (Hamlin) and 58.7% (Valencia), whereas for AS fruit the decay rates were 6.7% (Hamlin) and 5.3% (Valencia). Diplodia colonization of S fruit AZ-C was observed by scanning electron microscopy and confirmed by PCR test and morphology of conidia in isolates from the AZ-C after surface sterilization. DiplodiaCTvalues were negatively correlated with ethylene production (R= −0.838 for Hamlin;R= −0.858 for Valencia) in S fruit, and positively correlated with fruit detachment force (R= 0.855 for Hamlin;R= 0.850 for Valencia), suggesting that diplodia colonization in AZ-C may exacerbate HLB-associated preharvest fruit drop.

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 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 Evaluation of the synergy between Schwanniomyces vanrijiae and propolis in the control of Penicillium digitatum on lemons

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Kamal A. M. Abo-Elyousr ◽  
Adel D. Al-Qurashi ◽  
Najeeb M. Almasoudi
Keyword(s):  
Fungal Pathogen ◽  
Mycelial Growth ◽  
Penicillium Digitatum ◽  
In Vitro Experiments ◽  
Combined Application ◽  
Green Mold ◽  
Ethanolic Extracts ◽  
Production Losses

Abstract Background Green mold disease on citrus caused by Penicillium digitatum is the most serious and destructive disease. It is causing 90% of production losses during post-harvest handling. Results In this study, the activity of seven yeast isolates from lemons against P. digitatum, a fungal pathogen that causes the green mold disease in lemons, was isolated and examined. In vitro experiments showed that isolate three significantly reduced pathogen growths and were later identified as Schwanniomyces vanrijiae. In addition, 3% ethanolic extracts of propolis (EEP) caused a strong mycelial growth inhibition with inhibition halos of 1.4 cm. The use of S. vanrijiae treatments to protect lemon fruits from green mold has been reported (55%); however, reports describing the application of EEP are limited (40%). Thus, the effectiveness of the combination of S. vanrijiae and 3% EEP in an antagonistic mixture for protecting lemon fruits from P. digitatum was examined. EEP and S. vanrijiae treatments were applied alone and in combination in both in vitro and in vivo conditions. The combined application of 3% EEP + S. vanrijiae on lemon fruits significantly reduced the severity and incidence of green mold (80 and 93.7%, respectively) with much higher efficacy than either treatment alone. Lemon fruits treated with both S. vanrijiae and 3% EEP showed increased levels of antioxidants, peroxidase (POD), polyphenol oxidase (PPO), and phenol than the untreated control. Conclusion The results indicated that the combination of S. vanrijiae + 3% EEP can strongly protect lemon fruits from green mold compared with the sole application of either bioagent.

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.

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