Journal of Fungi

Research

18 pages, 3646 KiB

Open AccessArticle

Streptomyces spp. Strains as Potential Biological Control Agents against Verticillium Wilt of Olive

by Miriam Díaz-Díaz, Begoña I. Antón-Domínguez, María Carmen Raya, Alexander Bernal-Cabrera, Ricardo Medina-Marrero, Antonio Trapero and Carlos Agustí-Brisach

J. Fungi 2024, 10(2), 138; https://doi.org/10.3390/jof10020138 - 08 Feb 2024

Viewed by 971

Abstract

Verticillium wilt of olive (VWO) caused by Verticillium dahliae is considered a major olive (Olea europaea) disease in Mediterranean-type climate regions. The lack of effective chemical products against VWO makes it necessary to search for alternatives such as biological control. The [...] Read more.

Verticillium wilt of olive (VWO) caused by Verticillium dahliae is considered a major olive (Olea europaea) disease in Mediterranean-type climate regions. The lack of effective chemical products against VWO makes it necessary to search for alternatives such as biological control. The main goal of this study was to evaluate the effect of six Streptomyces spp. strains as biological control agents (BCAs) against VWO. All of them were molecularly characterized by sequencing 16S or 23S rRNA genes and via phylogenetic analysis. Their effect was evaluated in vitro on the mycelial growth of V. dahliae (isolates V004 and V323) and on microsclerotia (MS) viability using naturally infested soils. Bioassays in olive plants inoculated with V. dahliae were also conducted to evaluate their effect against disease progress. In all the experiments, the reference BCAs Fusarium oxysporum FO12 and Aureobasidium pullulans AP08 were included for comparative purposes. The six strains were identified as Streptomyces spp., and they were considered as potential new species. All the BCAs, including Streptomyces strains, showed a significant effect on mycelial growth inhibition for both V. dahliae isolates compared to the positive control, with FO12 being the most effective, followed by AP08, while the Streptomyces spp. strains showed an intermediate effect. All the BCAs tested also showed a significant effect on the inhibition of germination of V. dahliae MS compared to the untreated control, with FO12 being the most effective treatment. Irrigation treatments with Streptomyces strain CBQ-EBa-21 or FO12 were significantly more effective in reducing disease severity and disease progress in olive plants inoculated with V. dahliae compared to the remaining treatments. This study represents the first approach to elucidating the potential effect of Streptomyces strains against VWO. Full article

(This article belongs to the Special Issue Diagnosis of Plant Pathogenic Fungi and Oomycetes and Plant Breeding for Disease Resistance, 3rd Edition)

► Show Figures

Figure 1

14 pages, 4725 KiB

Open AccessArticle

First Report of Diplodia quercivora and Neofusicoccum vitifusiforme Associated with Cankers and Necrosis of Holm Oak (Quercus ilex) in Declining Stands in Southern Italy

by Carmine Del Grosso, Davide Palmieri, Lucia Marchese, Luigi Melissano and Giuseppe Lima

J. Fungi 2024, 10(1), 35; https://doi.org/10.3390/jof10010035 - 03 Jan 2024

Viewed by 1120

Abstract

The emergence of new plant diseases is an increasingly important concern. Climate change is likely to be among the factors causing most of the emerging diseases endangering forest and tree heritage around the world. Such diseases may be caused by latent pathogens or [...] Read more.

The emergence of new plant diseases is an increasingly important concern. Climate change is likely to be among the factors causing most of the emerging diseases endangering forest and tree heritage around the world. Such diseases may be caused by latent pathogens or microorganisms cryptically associated with plants. The shift from a non-pathogenic to a pathogenic stage may depend on physiological alterations of the host, environmental changes, and/or stress factors. In some woods of the Salento Peninsula (Apulia Region, Italy), sudden declines of holm oak plants (Quercus ilex L.) have been observed since 2016. The morphological and molecular characterization of representative fungal isolates associated with cankers and necrosis in declining plants indicated that these isolates belong to the Botryosphaeriaceae family, and the most frequent species were Diplodia corticola and Diplodia quercivora, followed by Neofusicoccum vitifusiforme. In artificially inoculated young holm oak plants, both D. corticola and D. quercivora species produced intense and severe subcortical and leaf margin necrosis. N. vitifusiforme, although less aggressive, induced the same symptoms. Our research, in addition to confirming the involvement of D. corticola in olm oak decline, represents the first report of D. quercivora as a new pathogen of Q. ilex in Italy. Furthermore, to the best of our knowledge, we also found N. vitifusiforme as a new pathogen of Q. ilex. Full article

(This article belongs to the Special Issue Diagnosis of Plant Pathogenic Fungi and Oomycetes and Plant Breeding for Disease Resistance, 3rd Edition)

► Show Figures

Figure 1

19 pages, 3079 KiB

Open AccessArticle

Defense Mechanisms Induced by Celery Seed Essential Oil against Powdery Mildew Incited by Podosphaera fusca in Cucumber

by Hajar Soleimani, Reza Mostowfizadeh-Ghalamfarsa, Mustafa Ghanadian, Akbar Karami and Santa Olga Cacciola

J. Fungi 2024, 10(1), 17; https://doi.org/10.3390/jof10010017 - 27 Dec 2023

Viewed by 1174

Abstract

This study aimed to evaluate the effectiveness of essential oil extracted from celery (Apium graveolens) seeds (CSEO) for the control of powdery mildew of cucumber (Cucumis sativus) incited by Podosphaera fusca and to investigate the metabolic and genetic defense [...] Read more.

This study aimed to evaluate the effectiveness of essential oil extracted from celery (Apium graveolens) seeds (CSEO) for the control of powdery mildew of cucumber (Cucumis sativus) incited by Podosphaera fusca and to investigate the metabolic and genetic defense mechanisms triggered by the treatment with this essential oil in cucumber seedlings. The main compounds in the CSEO as determined by gas chromatography–mass spectrometry (GC-MS) analysis were d-limonene, 3-butyl phthalide, β-selinene, and mandelic acid. The treatment with CSEO led to an increase in the content of both chlorophyll and phenolic/flavonoid compounds in cucumber leaves. In greenhouse tests, the application of CSEO reduced by 60% the disease severity on leaves of cucumber plants and stimulated the activity of defense-related enzymes such as β-1,3-glucanase, chitinase, phenylalanine ammonia-lyase, peroxidase, and polyphenol oxidase. Moreover, treatment with CSEO induced overexpression of β-1,3-glucanase, chitinase, and phenylalanine ammonia-lyase genes. A highly significant correlation was found between the β-1,3-glucanase, chitinase, and phenylalanine ammonia-lyase enzymatic activities and the relative expression of the corresponding encoding genes in both inoculated and non-inoculated cucumber seedlings treated with the essential oil. Overall, this study showed that CSEO is a promising eco-friendly candidate fungicide that can be exploited to control cucumber powdery mildew. Full article

(This article belongs to the Special Issue Diagnosis of Plant Pathogenic Fungi and Oomycetes and Plant Breeding for Disease Resistance, 3rd Edition)

► Show Figures

Figure 1

12 pages, 3521 KiB

Open AccessArticle

Gene Family Expansion during the Adaptation of Colletotrichum gloeosporioides to Woody Plants

by Fanli Meng and Chengming Tian

J. Fungi 2023, 9(12), 1185; https://doi.org/10.3390/jof9121185 - 11 Dec 2023

Cited by 2 | Viewed by 1010

Abstract

Gene gains/losses during evolution are critical for the adaptation of organisms to new environments or hosts. However, it remains unknown whether gene family expansions facilitated the adaptation of phytopathogenic fungi to woody plants. In this study, we compared the newly sequenced genome of [...] Read more.

Gene gains/losses during evolution are critical for the adaptation of organisms to new environments or hosts. However, it remains unknown whether gene family expansions facilitated the adaptation of phytopathogenic fungi to woody plants. In this study, we compared the newly sequenced genome of the Colletotrichum gloeosporioides strain CFCC80308 with the genomes of two other C. gloeosporioides strains, Cg-14 and Lc-1, isolated from Persea americana and Liriodendron leaves, respectively. The genes in the expanded families, which were associated with plant surface signal recognition, encoded various proteins, including glycosyde hydrolases (GHs) and cytochrome P450. Interestingly, there was a substantial increase in the number of GH family genes in CFCC80308. Specifically, there were 368 enriched genes in the GH families (e.g., GH1, GH3, GH10, GH12, GH15, GH16, GH17, GH18, GH25, GH32, GH53, GH61, GH76, and GH81); the expression levels of these genes were highly up-regulated during the infection of poplar trees. Additionally, the GH17 family was larger in CFCC80308 than in C. gloeosporioides strains Cg-14 and Lc-1. Furthermore, the expansion of the MP65-encoding gene family during the adaptation of Colletotrichum species to woody plants was consistent with the importance of gene gains/losses for the adaptation of organisms to their environments. This study has clarified how C. gloeosporioides adapted to woody plants during evolution. Full article

(This article belongs to the Special Issue Diagnosis of Plant Pathogenic Fungi and Oomycetes and Plant Breeding for Disease Resistance, 3rd Edition)

► Show Figures

Figure 1

8 pages, 1603 KiB

Open AccessCommunication

Exogenous dsRNA-Induced Silencing of the Phytophthora infestans Elicitin Genes inf1 and inf4 Suppresses Its Pathogenicity on Potato Plants

by Artemii A. Ivanov and Tatiana S. Golubeva

J. Fungi 2023, 9(11), 1100; https://doi.org/10.3390/jof9111100 - 11 Nov 2023

Viewed by 1085

Abstract

Phytophthora infestans, an Oomycete pathogen, has a devastating impact on potato agriculture, leading to the extensive use of chemical fungicides to prevent its outbreaks. Spraying double-stranded RNAs to suppress specific genes of the pathogen via the RNA interference (RNAi) pathway may provide [...] Read more.

Phytophthora infestans, an Oomycete pathogen, has a devastating impact on potato agriculture, leading to the extensive use of chemical fungicides to prevent its outbreaks. Spraying double-stranded RNAs to suppress specific genes of the pathogen via the RNA interference (RNAi) pathway may provide an environmentally friendly alternative to chemicals. However, this novel approach will require various target genes and application strategies to be tested. Using the L4440 backbone, we have designed two plasmids to express dsRNA targeting inf1 and inf4 genes of P. infestans that are known to contribute to the disease development at different stages. The dsRNA produced by the bacteria was tested on potato explants and demonstrated a statistically significant reduction in lesions five days after inoculation compared to water treatment. The study results allow us to consider our approach to be promising for potato late blight control. Full article

(This article belongs to the Special Issue Diagnosis of Plant Pathogenic Fungi and Oomycetes and Plant Breeding for Disease Resistance, 3rd Edition)

► Show Figures

Figure 1

16 pages, 2108 KiB

Open AccessArticle

Pyricularia’s Capability of Infecting Different Grasses in Two Regions of Mexico

by Ivan Sequera-Grappin, Elsa Ventura-Zapata, Erika Alicia De la Cruz-Arguijo, Claudia Patricia Larralde-Corona and Jose Alberto Narváez-Zapata

J. Fungi 2023, 9(11), 1055; https://doi.org/10.3390/jof9111055 - 27 Oct 2023

Viewed by 846

Abstract

The genus Pyricularia includes species that are phytopathogenic fungi, which infect different species of Poaceae, such as rice and sorghum. However, few isolates have been genetically characterized in North America. The current study addresses this lack of information by characterizing an additional 57 [...] Read more.

The genus Pyricularia includes species that are phytopathogenic fungi, which infect different species of Poaceae, such as rice and sorghum. However, few isolates have been genetically characterized in North America. The current study addresses this lack of information by characterizing an additional 57 strains of three grasses (Stenotaphrum secundatum, Cenchrus ciliaris and Digitaria ciliaris) from two distant regions of Mexico. A Pyricularia dataset with ITS sequences retrieved from GenBank and the studied sequences were used to build a haplotype network that allowed us to identify a few redundant haplotypes highly related to P. oryzae species. An analysis considering only the Mexican sequences allowed us to identify non-redundant haplotypes in the isolates of C. ciliaris and D. ciliaris, with a high identity with P. pennisetigena. The Pot2-TIR genomic fingerprinting technique resulted in high variability and allowed for the isolates to be grouped according to their host grass, whilst the ERIC-PCR technique was able to separate the isolates according to their host grass and their region of collection. Representative isolates from different host grasses were chosen to explore the pathogenic potential of these isolates. The selected isolates showed a differential pathogenic profile. Cross-infection with representative isolates from S. secundatum and C. ciliaris showed that these were unable to infect D. ciliaris grass and that the DY1 isolate from D. ciliaris was only able to infect its host grass. The results support the identification of pathogenic strains of Pyricularia isolates and their cross-infection potential in different grasses surrounding important crops in Mexico. Full article

(This article belongs to the Special Issue Diagnosis of Plant Pathogenic Fungi and Oomycetes and Plant Breeding for Disease Resistance, 3rd Edition)

► Show Figures

Figure 1

14 pages, 10759 KiB

Open AccessArticle

Replacing Mancozeb with Alternative Fungicides for the Control of Late Blight in Potato

by Yariv Ben Naim and Yigal Cohen

J. Fungi 2023, 9(11), 1046; https://doi.org/10.3390/jof9111046 - 25 Oct 2023

Cited by 1 | Viewed by 1808

Abstract

Mancozeb (MZ) is a broadly used fungicide for the control of plant diseases, including late blight in potatoes caused by the oomycete Phytophthora infestans (Mont.) De Bary. MZ has been banned for agricultural use by the European Union as of January 2022 due [...] Read more.

Mancozeb (MZ) is a broadly used fungicide for the control of plant diseases, including late blight in potatoes caused by the oomycete Phytophthora infestans (Mont.) De Bary. MZ has been banned for agricultural use by the European Union as of January 2022 due to its hazards to humans and the environment. In a search for replacement fungicides, twenty-seven registered anti-oomycete fungicidal preparations were evaluated for their ability to mitigate the threat of this disease. Fourteen fungicides provided good control (≥75%) of late blight in potted potato and tomato plants in growth chambers. However, in Tunnel Experiment 1, only three fungicides provided effective control of P. infestans in potatoes: Cyazofamid (Ranman, a QiI inhibitor), Mandipropamid (Revus, a CAA inhibitor), and Oxathiapiprolin + Benthiavalicarb (Zorvek Endavia, an OSBP inhibitor + CAA inhibitor). In Tunnel Experiment 2, these three fungicides were applied at the recommended doses at 7-, 9-, and 21-day intervals, respectively, totaling 6, 4, and 2 sprays during the season. At 39 days post-inoculation (dpi), control efficacy increased in the following order: Zorvec Endavia > Ranman > Revus > Mancozeb. Two sprays of Zorvec Endavia were significantly more effective in controlling the blight than six sprays of Ranman or four sprays of Revus. We, therefore, recommend using these three fungicides as replacements for mancozeb for the control of late blight in potatoes. A spray program that alternates between these three fungicides may be effective in controlling the disease and also in avoiding the build-up of resistance in P. infestans to mandipropamid and oxathiapiprolin. Full article

(This article belongs to the Special Issue Diagnosis of Plant Pathogenic Fungi and Oomycetes and Plant Breeding for Disease Resistance, 3rd Edition)

► Show Figures

Figure 1

15 pages, 6812 KiB

Open AccessArticle

Characterization of Alternaria alternata and Alternaria scrophulariae Brown Spot in Colombian quinoa (Chenopodium quinoa)

by Ingrid Rocío Fonseca-Guerra, Mayra Eleonora Beltrán Pineda and Martha Elizabeth Benavides Rozo

J. Fungi 2023, 9(9), 947; https://doi.org/10.3390/jof9090947 - 20 Sep 2023

Viewed by 1208

Abstract

Alternaria is a saprophytic and opportunistic fungus with a worldwide distribution that can affect the quality of various agricultural products, such as fruits, cereals, and pseudocereals. This research was carried out to investigate the population of this genus associated with quinoa cultivation in [...] Read more.

Alternaria is a saprophytic and opportunistic fungus with a worldwide distribution that can affect the quality of various agricultural products, such as fruits, cereals, and pseudocereals. This research was carried out to investigate the population of this genus associated with quinoa cultivation in plots located in the Boyacá department (Colombia), the country’s third-largest quinoa-producing department. The present study found 17 Alternaria isolates, of which 13 were identified as A. alternata and 4 as A. scrophulariae (formerly A. conjuncta) employed molecular markers of internal transcribed spacer (ITS) region and translation elongation factor 1α (TEF-1α). In the pathogenicity test under greenhouse conditions, all the Alternaria isolates showed some degree of pathogenicity on Piartal quinoa cultivar plants although no significant differences were found in isolates. The severity indices ranged from 2 to 5, and the percentage of affected leaves per plant ranged between 15% and 40%. This fungus affected the foliar tissue of quinoa, resulting in chlorotic and necrotic spots, symptoms that can generate a reduction in the quality and productivity of crops. This is the first time that the pathogenicity of Alternaria spp. in the Piartal variety has been described and the first report of this genera in quinoa crops of Colombia. Full article

(This article belongs to the Special Issue Diagnosis of Plant Pathogenic Fungi and Oomycetes and Plant Breeding for Disease Resistance, 3rd Edition)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Diagnosis of Plant Pathogenic Fungi and Oomycetes and Plant Breeding for Disease Resistance, 3rd Edition

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (8 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI