Rhizopus stolonifer (Soft Rot)

doi:10.1016/B978-0-12-411552-1.00001-6

Postharvest Decay

Control Strategies

2014, Pages 1-44

https://doi.org/10.1016/B978-0-12-411552-1.00001-6 Get rights and content

Abstract

Rhizopus stolonifer is considered the most important species in the genus Rhizopus. Disease symptoms that characterize R. stolonifer infection are watery areas quickly covered by coarse, gray hairy mycelia forming a mass of black sporangia at their tips. Infection usually occurs during harvest and handling. Due to the wide array of hosts that R. stolonifer can infect and its fast penetration and colonization, it has become an important target to control. Overall, R. stolonifer is controlled using synthetic fungicides; among the various registered fungicides are thiabendazole, benomyl, imazalil, propiconazole and thiocarbamates. The fungicides fluodioxonyl, tebuconazole, fenhexamide and azoxystrobin have also achieved notable control of this fungus. Sanitizers like chlorine, sodium hypochlorite, calcium hypochlorite, ozone and peracetic acid have shown to have good control on Rhizopus. Of the various non-conventional methods under experimentation, antagonists have attracted considerable attention. Bacteria including Pantoe agglomerans, Enterobacter cloacae, Pseudomonas syringae, and Bacillus spp., as well as yeasts of the genera Pichia, Kloeckera, Candida, Cryptoccoccus, Metschnikowia and Acremonium, have exerted a significant control on this fungus. Aqueous plant extracts belonging to the botanical families Amaryllidaceae, Annonaceae, Arecaceae, Bromeliaceae, Caricaceae, Lamiaceae, Lauraceae, Leguminosae, Meliacea, Myrtaceae, Pinaceae, Sapotaceae, Solanaceae and Urticaceae, along with the essential oils of the genera Thymus, Cinnamom, Origanum and Citrus, have also produced excellent results under experimentation. UVC irradiation levels of up to 3.6 kJm² showed levels of control up to 50% on R. stolonifer. Chitosan, a widely known chitin derivative, alone or in combination with other natural products, has been able to reduce significantly Rhizopus soft rot on various horticultural commodities at various concentrations. Volatiles, hypobaric atmospheres, salts, minerals, plant phenolics, hot water, wax and salicylic acid have resulted in good control methods with promising applications.

References (0)

Cited by (45)

Rhizopus stolonifer and related control strategies in postharvest fruit: A review
2024, Heliyon
Rhizopus stolonifer is one of the main pathogens in postharvest storage logistics of more than 100 kinds of fruit, such as strawberries, tomatoes and melons. In this paper, the research on the morphology and detection, pathogenicity and infection mechanism of Rhizopus stolonifer was reviewed. The control methods of Rhizopus stolonifer in recent years was summarized from three dimensions of physics, chemistry and biology, including the nanomaterials, biological metabolites, light control bacteria, etc. Future direction of postharvest Rhizopus stolonifer infection control was analyzed from two aspects of pathogenic mechanism research and new composite technology. The information provided in this review will help researchers and technicians to deepen their understanding of the pathogenicity of Rhizopus stolonifer, and develop more effective control methods in the future.
Electrosprayed hydroxypropyl methylcellulose microcapsules containing Rhus microphylla fruit extracts and their application in strawberry (Fragaria × ananassa) preservation
2023, LWT
Encapsulation is used to incorporate a wide range of compounds, which is beneficial for protecting and improving the bioactivity of plant extracts. In this study, the objectives were to develop hydroxypropyl methylcellulose microcapsules containing two different extracts from Rhus microphylla fruit namely RmA (obtained by conventional agitation) and RmO (obtained by ohmic heating) using electrohydrodynamic processing. The microcapsules were then characterized through Scanning Electron Microscopy (SEM), ATR-Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Additionally, the study aimed to evaluate their influence on strawberry shelf life parameters. Spherical microcapsules with a particle size ranged from 2.05 to 2.41 μm were successfully obtained, and FTIR analysis confirmed the proper incorporation of the extracts. The microcapsules containing RmA extract (MC-RmA) exhibited superior antioxidant and antifungal activities in vitro. Consequently, their efficacy in preserving the quality of strawberry fruits during storage at 4 ± 1 °C and 85% relative humidity (RH) was evaluated at concentrations of 0.25% and 0.50% (w/v). After 14 days, the MC-RmA-treated fruits showed reduced weight loss, improved firmness, and unchanged color. Furthermore, the gradual release of antifungal activity from MC-RmA suggests their potential as a novel solution to mitigate postharvest losses in strawberry fruits.
Efficacy of Debaryomyce hansenii in the biocontrol for postharvest soft rot of strawberry and investigation of the physiological mechanisms involved
2022, Biological Control
Citation Excerpt :
In addition, fresh strawberry can be processed into strawberry wine, strawberry juice, strawberry preserves, strawberry canning, strawberry jam, etc. However, strawberries are susceptible to mechanical damage during storage, transportation and marketing, and strawberries are susceptible to postharvest diseases caused by pathogens, especially soft rot caused by R. stolonifer (Bautista-Baños et al., 2014; Oliveira et al., 2019). The current strawberry disease prevention and control agents mainly involve benzimidazoles, dicarboximide and other chemical fungicides.
The postharvest disease of strawberries caused by Rhizopus stolonifer caused enormous financial losses. This study investigates the efficacy of antagonistic yeast Debaryomyce hansenii in the biocontrol of postharvest soft rot of strawberries and the physiological mechanisms involved. The results showed that D. hansenii significantly reduced the incidence of postharvest soft rot of strawberry, reduced the natural decay incidence of postharvest strawberry, and had no adverse effects on quality parameters of strawberries. In vitro experiments showed that D. hansenii reduced the spore germination rate and germ tube length of R. stolonifer. D. hansenii can also stably colonize the surface and wounds of strawberries at either 4 °C or 20 °C. Meanwhile, the activities of antioxidant-related enzymes superoxide dismutase, peroxidase, catalase, ascorbate oxidase and resistance-related enzymes polyphenol oxidase and phenylalanine ammonia-lyase were significantly higher in D. hansenii-treated strawberries than in control. Meanwhile, the contents of resistance-related substances including total phenols, flavonoids and anthocyanins were also increased in D. hansenii-treated strawberries. This study suggested that D. hansenii has the potential to control postharvest soft rot of strawberry by the mechanism involving inhibition of spore germination and germ tube length of R. stolonifer and induction of increased activities of defense-related enzymes and substances in strawberry.
New insights into the cell wall preservation by 1-methylcyclopropene treatment in harvest-ripe strawberry fruit
2022, Scientia Horticulturae
Citation Excerpt :
The fruit cell wall acts as a pre-formed barrier against invasive microorganisms both during pre- and postharvest ripening, and the disassembly of this structure is closely related to pathogen attack (Cantu et al., 2008). Necrotrophic fungi such as B. cinerea and R. stolonifer employ mechanical force and/or release cell wall-degrading enzymes to break down the structure that prevents access to cellular nutrients (Williamson et al., 2007; Bautista-Baños et al., 2014). Results obtained here of pathogens in vitro growing assays, suggest that 1-MCP treatment would result in stronger and more integral cell walls from harvest-ripe strawberries which are less accessible to Botrytis and Rhizopus hydrolytic enzymes.
The purpose of the present work was to provide novel knowledge about the mechanisms underlying the preservation of strawberry fruit by 1-methylcyclopropene (1-MCP) treatment during storage. Harvest-ripe strawberries were treated with 1-MCP for ten hours at 22 °C and then stored for ten days at 4 °C and two days at 20 °C. 1-MCP treatment significantly delayed the loss of fruit firmness and the accumulation of anthocyanins during storage, whereas sustained pH, titratable acidity, total sugars, and phenolic compounds values. 1-MCP treatment reduced the in vitro growth of fungal pathogens Botrytis cinerea and Rhizopus stolonifer when using isolated fruit cell walls as only carbon source. Also, 1-MCP treatment was effective in delaying the appearance of fungal lesions and reducing their severity in comparison with non-treated fruit. 1-MCP treated fruit showed higher amounts of ionically bounded pectins and hemicellulose fractions than controls. Treated fruit showed an increase of pectin methylesterase activity, and the inhibition of polygalacturonase, β-galactosidase, α-arabinofuranosidase, and β-xylosidase activities. 1-MCP application modified the expression of relevant genes related to strawberry fruit firmness, increasing the FaPME1 and FaXTH1 mRNA abundance and down-regulating FaPG1, FaPLC, and FaXTH2 expression. Treatment delayed the in vitro cell wall swelling and the collapse of the hemicellulose-cellulose mesh during storage. The effect of 1-MCP on the cell wall composition and its accessibility to necrotrophic pathogens through an up-regulation of endogenous pectin methylesterases and xyloglucan transglycosylases and a down-regulation of lyases and hydrolases is the first report in commercial-ripe strawberries. Moreover, the effect of 1-MCP treatment combined with a dip in a CaCl₂ solution on the firmness of strawberry fruit was evaluated. As a result, 1-MCP/CaCl₂ treatment rendered significantly firmer fruit when compared with control, and also with 1-MCP, or CaCl₂ individual applications.
Monitoring the infection process of Rhizopus stolonifer on strawberry fruit during storage using films based on chitosan/polyvinyl alcohol/polyvinylpyrrolidone and plant extracts
2021, International Journal of Biological Macromolecules
Different formulations based on nanoparticles of chitosan-plant extracts were evaluated to detect the infection process from the earliest stage of the fungus Rhizopus stolonifer on strawberry fruit during storage. Chitosan/polyvinyl alcohol (Ch/PVA) and chitosan/polyvinylpyrrolidone (Ch/PVP) films enriched with nanoparticles (NPs) of chitosan blended with plant extracts were prepared. They were placed inside a plastic package containing inoculated fruits and stored at 25 °C for 72 h. The thickness values of the films were in the range of 0.10 to 0.25 mm. All samples showed a maximum absorbance peak of about 300–320 nm; however, the Ch/PVP films enriched with NPs of chitosan and 10% of radish extract had an evident decrease in the optical absorbance as the fungal infection progressed. Additionally, as observed by scanning electron microscopy, the cross-section and surface morphology of films were not modified during storage, and the growth of R. stolonifer was evident after 48 h. Therefore, the Ch/PVP films enriched with chitosan NPs blended with 10% radish extract could be a reliable indicator of this fungus's growth.
Detection of Alternaria alternata in tomato juice and fresh fruit by the production of its biomass, respiration, and volatile compounds
2021, International Journal of Food Microbiology
Citation Excerpt :
It has been mentioned that several species from the genus Alternaria can cause tomato diseases, including A. alternata. Nevertheless, during their postharvest stage, this species and Rhizopus stolonifer are the most important causal agents (Bautista-Baños et al., 2008; Bautista-Baños et al., 2014; SAGARPA, 2017; Troncoso-Rojas and Tiznado-Hernandez, 2014). In addition, the growth rate of postharvest microorganisms can be affected by the ripening stage of the fruit.
Tomato is widely consumed and marketed as juice, puree, or fresh product. Nevertheless, 30% of its harvest volume is lost because of the fungus Alternaria alternata. This research aimed to provide early detection methods for this fungal decay on tomato juice and fresh fruit. Biomass content, CO₂, O₂ and volatile compounds (VOCs) during A. alternata growth in tomato juice and fruit at two ripening stages (breaker and red colour) were evaluated. Additionally, CO₂ and VOCs data set were analysed with a hierarchical cluster technique (HCA) to explore the differences between inoculated and non-inoculated samples. Biomass was determined by gravimetry, CO₂ and O₂ by gas chromatography (GC), and VOCs by GC-mass spectrometry. Biomass content was not drastically modified by tomato's ripening stage (3–6 mg of dry weight). CO₂ in tomato juice was considerably higher in the inoculated samples with A. alternata (27–63%) than in the non-inoculated ones (2.8–6.6%), regardless of the ripeness stage; while in tomato fruit CO₂ was higher at breaker stage and inoculated with A. alternata (33–41%) than the remaining treatments (9–23%). It was also observed that, except for limonene, trans-sabinene hydrate, and rhodovibrin, VOCs' release during the interaction between tomato juice and A. alternata was different from the fresh tomato and A. alternata interaction. Only the HCA based on CO₂ data showed clear differences between the inoculated and non-inoculated tomato juice and fruit at both ripening stages.

View all citing articles on Scopus

View full text

Chapter 1 - Rhizopus stolonifer (Soft Rot)

Abstract