Etiological agents of crown rot of organic bananas in the Dominican Republic (2023)

Fusarium proliferatum causes crown rot of harvested banana fruit, but the underlying infection mechanism is still unclear. Here, proteomic changes in the banana peel with and without inoculation with F. proliferatum were evaluated. In addition, we investigated the effects of F. proliferatum infection on cell structure, hormone content, primary metabolites, and defense-related enzyme activities in banana peels. Our results showed that infection with F. proliferatum mainly affects cell wall components and inhibits the activities of polyphenol oxidase, peroxidase and chitinase. Gel-free quantitative proteome analysis showed 92 down-regulated and 29 up-regulated banana peel proteins after F. proliferatum infection. These proteins were mainly related to the defense response to biotic stress, chloroplast structure and function, JA signaling pathway and primary metabolism. Although levels of jasmonic acid (JA) and the coronatin-insensitive (COI) protein of the JA signaling component were induced by F. proliferatum infection, defense genes/proteins responsible for JA were downregulated. In contrast, expression of senescence-related genes was induced by F. proliferatum, suggesting that F. proliferatum modulated the JA signal to accelerate senescence of banana fruit. Furthermore, salicylic acid (SA) levels and SA signaling for resistance acquisition by F. proliferatum were inhibited. Taken together, these results suggest that F. proliferatum depolymerizes the cell wall barrier, impairs the defense system in banana fruit, and activates the non-defensive JA signaling pathway that accelerates senescence in banana fruit. This study provided an elucidation of the main signaling pathways disrupted by F. proliferatum in banana fruit, which will facilitate the development of a new strategy to control banana fruit crown rot and improve banana cultivars.

Fruit production can be affected by the presence of phytopathogens in the field, which can lead to significant losses due to post-harvest disease. The use of agricultural chemicals to control disease is a common practice. However, consumers are aware of the presence of chemical residues in fruit. In this context, new disease control technologies must be developed. They must be effective and safe for humans and have no impact on the environment. This chapter summarizes the characteristics and properties of nanoemulsions as an alternative for postharvest disease control.

Seven Fusarium species isolated from rotten bananas were analyzed for their mycotoxicity. The first pathogenicity test showed symptoms of Fusarium rot infection when the Fusarium isolates were inoculated onto damaged banana fruit. The second pathogenicity test, in which Nicotiana seedlings were inoculated with Fusarium isolate filtrates, revealed evidence of pathogenicity for six of the Fusarium species. One species, Fusarium oxysporum, showed no pathogenicity symptoms in Nicotiana seedlings. It also did not produce the mycotoxins fumonisin, zearalenone and deoxynivalenol produced by all other species. However, mycotoxin concentrations in the pathogenicity test with banana fruits did not correlate with disease severity. We conclude that pathogenicity is a complex problem regulated by many factors and multiple toxins, and that pathogenicity assessment requires bioassays with a multi-mycotoxin approach.

The lack of in-depth knowledge of plant pathogenic fungal biofilms is reflected in the few existing environmentally friendly options for combating fungal plant diseases. In fact, chemical fungicides still dominate the market, but today's concerns about their true effectiveness, increased awareness of the risk they pose to human health and the environment, and the spread of fungicide resistance have all led to the market currently being almost zero - Tolerance over for pesticide residues in fruit and vegetables. Here, essential oils (PK and PK-IK) from the edible leaves of two cultivars of Perilla frutescens are proposed as new, effective, non-toxic, environmentally friendly, pesticide-free options suitable for a preventive or integrative approach to sustainable crop protection and product preservation. PK and PK-IK were extracted and characterized and their ability to affect biofilm formation of the phytopathogenic model fungi Colletotrichum musae, Fusarium dimerum and Fusarium oxysporum at non-lethal doses was investigated. Both essential oils in 1000 and 2000 mgl⁻¹demonstrated excellent anti-biofilm performance: i) reduction in conidial adhesion by up to 80.3 ± 16.2%; ii) inhibition of conidia germination by up to 100.0 ± 0.0%; iii) to influence the structural development of the biofilm with a reduction in dry weight by up to 100.0 ± 0.0% and extracellular polysaccharides and proteins by up to 81.4 ± 8.0% and 51.0 ± 6, respectively 1 %. In all cases, PK-IK showed better activity than PK.

Agriculture, ecosystems and the environment, volume 239, 2017, pp. 173-181

One of the most devastating banana diseases is Fusarium wilt or Panama disease, which is caused by the soil-borne fungus Fusarium oxysporum f. sp. cubic (Foc). Foc is widespread in almost all banana growing areas and cannot be effectively controlled by chemical or biological measures. Fusarium wilt can potentially be controlled by promoting soil disease suppression. However, little is known about how soils achieve higher levels of disease suppression and how crop management can affect this. Banana cultivar (cultivar) Maçã, a cultivar highly susceptible to Foc race 1, was grown on an agroforestry managed farm in Pedra Dourada, Brazil, where Foc race 1 occurs in the soil. In some places on the farm banana plants by cv. Maçã remained prolific while others quickly declined. We hypothesized that differences in disease severity on the farm were due to different degrees of soil disease suppression. In this study, we evaluated the level of disease suppression at the different sites and highlighted possible factors that could promote disease suppression in the soil. Areas with confirmed occurrence of Foc race 1 were sampled and tested in greenhouse trials for suppression of Fusarium wilt. The composition of the plant community, the abiotic properties of the soil and the soil microbial community at the different sites were compared. Sites with higher levels of disease suppression were characterized by low densities of susceptible CVs. Maçã, a large variety of other banana cultivars, higher clay content, higher pH and lower graminoid ground cover. Banana CV. Ouro was only present in the three most oppressive areas. The results of this study suggest that in soils with favorable abiotic properties there is a good plant arrangement where cv. Maçã is grown in mixed stands with other banana varieties and can help suppress Fusarium wilt.

Postharvest Biology and Technology, Band 173, 2021, Artikel 111407

Dry rot is a post-harvest emerging disease of garlic (Allium sativum) attributed to Fusarium proliferatum which has caused huge economic losses in recent years. In this study, we aimed to detect the presence of F. proliferatum on post-harvest garlic bulbs during long-term storage and to identify other fungal species associated with garlic dry rot. We also quantified fumonisin levels in symptomatic and asymptomatic cloves. A total of 100 plants from three production seasons on six farms in northern Italy were sampled at three time points (at harvest, processing and 6 months after storage at -4 °C). The Fusarium garlic pathosystem has been divided into two parts: basal plate/root and bulb. F. proliferatum was the dominant fungus in infected bulbs and was confirmed to cause dry rot in garlic after harvest (average incidence: 35.4%). F. oxysporum coexisted with F. proliferatum but only caused basal plate/root disease. The incidence of dry rot increased slightly during cold storage (from 14.6% at processing to 18.4% at 6 months storage). Although the occurrence of F. proliferatum remained stable during cold storage, fumonisins were produced. Symptomatic cloves were more heavily contaminated than asymptomatic cloves, both by the fungus (mean incidence 39% vs. 25.3%) and by the toxin (287.0 vs. 24.4 μg kg).⁻¹). These results suggest that cold storage delays dry rot development, but the risk of fumonisin-related health problems and occurrence of infection in asymptomatic cloves should be seriously considered.

Biological Control, Tape 137, 2019, Article 104016

Among the world's most consumed fruits, bananas are a tropical climate commodity that requires harvesting methods, storage and transportation that burden its commercialization. It is one of the food crops most susceptible to diseases such as B. Anthracnose caused by Colletotrichum musae, which is considered to be the main post-harvest disease of bananas. This pathogen is a dormant fungus that infects the fruit during pre-harvest. Symptoms appear after harvest at an advanced stage of maturity. Although effective, fungal control requires more than dusting. This is therefore not possible given the time that elapses between harvest and transport of the fruit when symptoms are already evident. In addition, this control method is subject to commercial and environmental restrictions that prevent this product from being certified organic, which adds value to the product. Biological control agents (BCAs) have been studied and used as an alternative to chemical control. Based on this information, we selected 12 bacteria from in vitro tests that are trivial for biocontrol agent selection. When tested in vivo, the following taxa were effective in controlling anthracnose: Bacillus velezensis, Enterobacter cloacae, Serratia marcescens and Stenotrophomonas maltophilia. B. velezensis performed similarly to thiabendazole (Tecto SC®). In addition, B. velezensis inhibited mycelial growth and pathogen sporulation and was positive for cellulase and xylanase activity, which are relevant mechanisms of action for a biocontrol agent. In addition, this bacterium can be considered as a BCA for direct application by spraying and dipping in fruit, or can be used systemically, since B. velezensis is non-pathogenic to humans.

Disinfection after harvesting fruit and vegetables, 2018, pp. 1-52

Fungi and bacteria cause various post-harvest diseases in fruit and vegetables during storage and transport. Infection is caused by these pathogens either at the pre-harvest stage in the field or post-harvest during storage and transport. There are three basic approaches to treating postharvest diseases in fruits and vegetables: prevention of infection, elimination of incipient or latent infection, and prevention of spread of the pathogen in host tissues. Physical, chemical and biological methods are used to control post-harvest diseases, but these have some limitations in individual cases. However, the effectiveness of these methods can be improved by combining two or three methods of post-harvest treatment to reduce post-harvest losses and also extend product shelf life.

Postharvest Decay, 2014, S. 189-231

Blue mold disease, caused by Penicillium expansum (Link), is the most economically important post-harvest disease of stored fruits and vegetables. Some fungal strains not only cause food spoilage but also produce the mycotoxin patulin. This chapter discusses pre- and post-harvest factors that affect the occurrence of blue mold. Synthetic fungicides provide control of blue mold disease, and the development of P. expansum resistance to benzimidazole fungicides in the 1980s has prompted the search for new, lower-risk fungicides, biological control agents (BCAs), and other control alternatives. To remove the obstacles that limit the effectiveness of conventional and biological control methods, future research and implementation should focus on the development of integrated disease management strategies that combine conventional and biological control systems with one or more of the physical, chemical, biological and genetic control methods. to ensure effective control of blue mold after harvest. This chapter reviews the nature of the post-harvest pathogen P. expansum and the blue mold disease it causes in fruits and vegetables, factors influencing pre-harvest, at-harvest and post-harvest infection, and conventional and alternative methods of controlling the pathogen and of blue -roan investigates disease in the camp. The literature review indicates that while apple blue mold and P. expansum have been extensively studied due to its economic importance in horticulture and the ability of some strains to produce the mycotoxin patulin that affects humans, other P. expansum and crop combinations have been less intensively studied.

Biopestizide, 2022, S. 261-275

Agricultural practices worldwide face numerous problems such as disease, drought, pests, reduced soil fertility, pollution and health risks from the use of toxic chemical pesticides. Phytopathogens pose a major obstacle to crop production, causing severe disease outbreaks and yield losses. Cauliflower wilt, caused by the soil-borne species complex Fusarium oxysporum and Ralstonia solanacearum, is a devastating disease that threatens the production and yield of several important crops. The main concern is that traditional disease control methods and chemicals are unable to combat these destructive pathogens. Therefore, it is imperative to find environmentally friendly biopesticides that help control wilt pathogens. Biopesticides are disease-fighting agents based on living microorganisms or natural products. Among the various biopesticides, Trichoderma is important and widespread for combating plant pathogens in agriculture. Trichoderma strains utilize a complex network of mechanisms, such as colonizing the soil and the host's root, colonizing a physical space and preventing the phytopathogens from multiplying, producing cell wall-degrading enzymes, producing antimicrobial metabolites that kill the pathogens, and inducing plant defense mechanisms that promotes plant development and improves plant tolerance to biotic and abiotic stresses. This chapter describes the potential fungal biopesticide Trichoderma spp. submitted. To control wilt diseases in various crops, the mechanism of Trichoderma spp. and its impact on agriculture.