Rhizopus Soft Rot on Citrus Fruit Caused by Rhizopus stolonifer in Korea

2002 ◽  
Vol 30 (2) ◽  
pp. 166-169 ◽  
Author(s):  
Jin-Hyeuk Kwon ◽  
Chang-Seuk Park
2009 ◽  
Vol 62 ◽  
pp. 402-402
Author(s):  
S.L. Lewthwaite ◽  
P.J. Wright

The predominant diseases of the commercial kumara (Ipomoea batatas) or sweetpotato crop are caused by fungal pathogens The field disease pink rot results from infection by the fungus Sclerotinia sclerotiorum Lesions form on vines but may spread down stems to the roots The widespread nature of this disease in sweetpotato appears peculiar to New Zealand Scurf is a disease caused by Monilochaetes infuscans which occurs in the field but may proliferate amongst stored roots The disease causes a superficial discolouration of the root surface which is mainly cosmetic but can also increase root water loss in storage Infection by Ceratocystis fimbriata produces a disease known as black rot The disease can be transmitted amongst plants at propagation but is particularly rampant amongst roots in storage This disease is readily transmitted and can cause severe economic loss Fusarium oxysporum causes surface rots in stored roots characterised by light to dark brown lesions that tend to be firm dry and superficial The lesions may be circular and centred on wounds caused by insects or mechanical damage at harvest Soft rot caused by Rhizopus stolonifer generally occurs in roots after they are washed and prepared for the market Fungal infection occurs through wounds or bruised tissue producing distinctive tufts of white fungal strands and black spores


Plant Disease ◽  
1998 ◽  
Vol 82 (6) ◽  
pp. 689-693 ◽  
Author(s):  
P. L. Sholberg

Vapors of acetic (1.9 or 2.5 μl/liter), formic (1.2 μl/liter), and propionic (2.5 μl/liter) acids were tested for postharvest decay control on 8 cherry, 14 pome, and 3 citrus fruit cultivars. Surfacesterilized fruit were inoculated with known fungal pathogens by drying 20-μl drops of spore suspension on marked locations on each fruit, placing at 10°C to equilibrate for approximately 24 h, and fumigating by evaporating the above acids in 12.7-liter airtight fumigation chambers for 30 min. Immediately after fumigation, the fruit were removed, aerated, aseptically injured, and placed at 20°C until decay occurred. All three fumigants controlled Monilinia fructicola, Penicillium expansum, and Rhizopus stolonifer on cherry. Formic acid increased fruit pitting on six of eight cultivars and was the only organic acid to increase blackening of cherry stems when compared to the control. Decay of pome fruit caused by P. expansum was reduced from 98% to 16, 4, or 8% by acetic, formic, and propionic acids, respectively, without injury to the fruit. Decay of citrus fruit by P. digitatum was reduced from 86 to 11% by all three acids, although browning of the fruit peel was observed on grapefruit and oranges fumigated with formic acid.


2019 ◽  
Vol 31 (2) ◽  
pp. 319-329
Author(s):  
Nivien A. Nafady ◽  
Saad A.M. Alamri ◽  
Elhagag Ahmed Hassan ◽  
Mohamed Hashem ◽  
Yasser S. Mostafa ◽  
...  

AbstractA reduction in crop spoilage and an increase in shelf-life is the goal of effective disease control methods. This study aimed to assess ZnO-nanoparticles (ZnO-NPs) as a safe, new protectant against Rhizopus soft rot of sweet potato. ZnO-NPs had a fungicidal effect against Rhizopus stolonifer when used at concentrations above 50 ppm. The results showed that tubers treated with ZnO-NPs exhibited fewer fungal populations (1.2 CFU per segment) than those that did not receive the treatment. Tubers infected with Rhizopus stolonifer and treated with ZnO-NPs showed no visible decay for up to 15 days, indicating that ZnO-NPs act as a coating layer on tuber surface. The greatest weight loss after 15 days of storage was reported in infected tubers (8.98%), followed by infected tubers treated with ZnO (6.54%) and infected tubers treated with ZnO-NPs (3.79%). The activity of cell-wall degrading enzymes, α-amylase and cellulase, were significantly increased in both infected tubers and those treated with ZnO, compared to the tubers treated with ZnO-NPs. These results confirm that coating with ZnO-NPs is an effective method of protecting sweet potato tubers from infection, maintaining their quality and increasing their shelf-life for up to 2 months in storage.


Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6905
Author(s):  
Mengxi Jiang ◽  
Xinyi Pang ◽  
Huawei Liu ◽  
Fuxing Lin ◽  
Fengxia Lu ◽  
...  

The soft rot disease caused by Rhizopus stolonifer is an important disease in cherry tomato fruit. In this study, the effect of iturin A on soft rot of cherry tomato and its influence on the storage quality of cherry tomato fruit were investigated. The results showed that 512 μg/mL of iturin A could effectively inhibit the incidence of soft rot of cherry tomato fruit. It was found that iturin A could induce the activity of resistance-related enzymes including phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD), glucanase (GLU), and chitinase (CHI), and active oxygen-related enzymes including ascorbate peroxidases (APX), superoxide dismutases (SOD), catalases (CAT), and glutathione reductase (GR) of cherry tomato fruit. In addition, iturin A treatment could slow down the weight loss of cherry tomato and soften the fruit. These results indicated that iturin A could retard the decay and improve the quality of cherry tomato fruit by both the inhibition growth of R. stolonifera and the inducing the resistance.


2014 ◽  
pp. 1-44 ◽  
Author(s):  
Silvia Bautista-Baños ◽  
Elsa Bosquez-Molina ◽  
Laura L. Barrera-Necha
Keyword(s):  
Soft Rot ◽  

Plant Disease ◽  
2002 ◽  
Vol 86 (4) ◽  
pp. 345-348 ◽  
Author(s):  
Gerald J. Holmes ◽  
Richard R. Stange

Susceptibility of stored sweetpotato roots (cvs. Beauregard and Hernandez) to Rhizopus soft rot caused by Rhizopus stolonifer was tested at 4- to 6-week intervals over a storage period of 335 days in 1998-1999 (year 1) and 1999-2000 (year 2). In each experiment, roots were wounded by four methods (puncture, bruise, broken, and scrape), inoculated with freshly harvested spores from 4- to 10-day-old cultures, and compared with a nonwounded but inoculated control for their susceptibility to decay. Roots were totally resistant to infection after harvest for 60 days in year 1 and 30 days in year 2. The bruise wound type was most commonly associated with infection, with disease incidence peaking 100 and 175 days after harvest in years 1 and 2, respectively. Inoculation by the puncture method followed a similar pattern in Hernandez but was ineffective in Beauregard. Following the peak in disease incidence at 100 or 175 days, susceptibility of roots declined to levels comparable to that of freshly harvested roots. This period of heightened susceptibility was longer in Hernandez than in Beauregard. The effects of injury types broken and scrape were more variable and did not show the same trend in both years.


2004 ◽  
Vol 50 (9) ◽  
pp. 737-744 ◽  
Author(s):  
K Manjula ◽  
G Krishna Kishore ◽  
A R Podile

In foliar and postharvest biocontrol systems, the use of active metabolites produced by antagonistic microorganisms is advantageous compared with the use of living microorganisms. Chitinases, a major group of hydrolytic enzymes produced by biocontrol agents, are involved in the lysis of cell walls of pathogenic fungi. In the present study, an attempt was made to test the partially purified β-1,4-N-acetylglucosaminidase (NAGase) of a biocontrol strain Bacillus subtilis AF 1 for control of rust in groundnut (caused by Puccinia arachidis) and soft rot in lemons (caused by Aspergillus niger). Four proteins of molecular mass 67, 40, 37, and 32 kDa were isolated from the culture filtrates of AF 1 by affinity chromatography, of which the 67-kDa protein has detectable chitinolytic ability. This protein (NAGase) effectively inhibited the in vitro growth of A. niger in microtitre plates. In the presence of NAGase, germination of urediniospores of P. arachidis was reduced by 96% compared with the control. In a detached leaf bioassay, NAGase reduced the rust lesion frequency by >60%. NAGase significantly reduced the incidence of soft rot in harvested lemon fruits. However, fresh cells and (or) alginate formulation of AF 1 were more effective than NAGase in control of both of the test plant – pathogen systems.Key words: chitinase, peanut rust, lemon fruit rot, biocontrol.


2013 ◽  
Vol 66 ◽  
pp. 223-228
Author(s):  
S.L. Lewthwaite ◽  
P.J. Wright ◽  
C.M. Triggs

Infection by the fungal pathogen Rhizopus stolonifer causes a postharvest disease in sweetpotato (Ipomoea batatas) roots known as soft rot In recent years due to changes in legislation prescribing acceptable agrichemical residues postwash applications of the fungicide dicloran can no longer be used on exported sweetpotato roots An important component of any alternate disease control system is cultivar resistance This study examined the range of responses within artificially inoculated roots of various cultivars under different wounding regimes While none of the cultivars evaluated was immune to infection they differed in their degree of susceptibility (P


Mycobiology ◽  
2001 ◽  
Vol 29 (3) ◽  
pp. 176-178 ◽  
Author(s):  
Jin-Hyeuk Kwon ◽  
Soo-Woong Kang ◽  
Jeong-Soo Kim ◽  
Chang-Seuk Park

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