scholarly journals Pseudomonas Isolates as Potential Biofungicides of Green Mold (Penicillium Digitatum) on Orange Fruit

2022 ◽  
Vol 22 (1) ◽  
pp. 142-150
Author(s):  
Redouan Qessaoui ◽  
Mariem Zanzan ◽  
Abdelhadi Ajerrar ◽  
Hind Lahmyed ◽  
Ahmed Boumair ◽  
...  
Keyword(s):  
Penicillium Digitatum ◽  
Green Mold ◽  
Orange Fruit

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 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 Evidence for Antibiosis and Induced Host Defense Reactions in the Interaction Between Verticillium lecanii and Penicillium digitatum, the Causal Agent of Green Mold

2000 ◽  
Vol 90 (9) ◽  
pp. 932-943 ◽  
Author(s):  
Nicole Benhamou ◽  
Jacques Brodeur
Keyword(s):  
Plasma Membrane ◽  
Host Cell ◽  
De Novo ◽  
Penicillium Digitatum ◽  
Verticillium Lecanii ◽  
Intercellular Interaction ◽  
Green Mold ◽  
Transmission Electron ◽  
Host Cell Wall ◽  
Host Cell Surface

Chronological events of the intercellular interaction between Verticillium lecanii and the postharvest pathogen Penicillium digitatum were investigated by transmission electron microscopy and gold cytochemistry. Growth inhibition of P. oligandrum as a response to V. lecanii attack correlated with striking host changes including retraction of the plasma membrane and cytoplasm disorganization. Such changes were associated with the deposition on the inner host cell surface of a chitin- and cellulose-enriched material which appeared to be laid down as a structural defense reaction. The accumulation of chitin in the newly formed material correlated with a decrease in the amount of wallbound chitin. However, the deposition of cellulose appeared to correspond to a de novo synthesis, as evidenced by the occurrence of cellulose-containing vesicles which released their content in the space between the invaginated plasma membrane and the host cell wall. Results of the present study provide the first ultrastructural and cytochemical evidence that antagonism, triggered by V. lecanii, is a multifaceted process in which antibiosis, with alteration of the host hyphae prior to contact with the antagonist, appears to be the key process in the antagonism against P. digitatum.

scholarly journals Harvesting and the Incidence of Green Mold on Texas Grapefruit

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 604e-604
Author(s):  
John E. Fucik
Keyword(s):  
Infection Rate ◽  
Penicillium Digitatum ◽  
Citrus Paradisi ◽  
Green Mold ◽  
Three Stages

The harvest of Rio Red grapefruit (Citrus paradisi Macf.) was “intercepted” at three stages: 1) unpicked fruit, 2) picked and carried to pallet box trailer, and 3) picked, carried, dumped in the pallet box and transported to the packing shed. Three harvesters picked fruit from four canopy locations on two trees each. At each intercept, half the fruit was dipped into a spore solution of green mold (Penicillium digitatum) and half left nontreated as controls. Intercept 1 fruit was dipped and left unpicked on the tree. After 10 days incubation, the rate of green mold infection and its location on the fruit was determined. Tests were run in May 1995 and Feb. and Apr. 1996. The rate of infection increased with each intercept, and treated fruit had 15 times the infection rate of the controls. The highest infection rate, 1.3%, occurred in May 1995 followed by Feb. (0.8%), and April (0.5%). Most infection sites appeared above and below the fruit's equator, rather than on its top or bottom exclusively. There were no effects associated with harvesters or the location of the fruit in the canopy.

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