scholarly journals Fungal microflora biodiversity of healthy and diseased Adansonia digitata and Sclerocarya birrea trees in Kenya

Topola ◽  
2020 ◽  
pp. 5-13
Author(s):  
Sheillah Cherotich ◽  
Japhet Muthamia ◽  
Jane Njuguna ◽  
Alice Muchugi ◽  
Daniel Otaye ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Morphological Characteristics ◽  
Fungal Species ◽  
Mitigation Strategies ◽  
Malt Extract ◽  
Adansonia Digitata ◽  
Sclerocarya Birrea ◽  
Sampling Locations ◽  
Pure Cultures ◽  
Single Hypha

A study was conducted in Eastern Kenya to assess incidence and severity of Adansonia digitata and Sclerocarya birrea diseases under seasonal variations, and to assess associated fungal genera and their distribution. Asymptomatic and symptomatic tissues were sampled from 175 randomly selected trees. Isolations were done from leaves, twigs and bark following laboratory standard procedures. Samples were plated on Malt Extract Agar (MEA) and incubated at 25°C for 7 days. Fungal colonies were evaluated, and pure cultures were obtained using a single hypha. Fungal pathogens were identified based on morphological characteristics of cultures and spores. Statistical analysis were done using GENSTAT version 18. Fungal morphotypes isolated included: Pestalotia (39.0%), Botryosphaeria (41.0%), Fusarium (12.0%), Alternaria (7.9%) and Cladosporium (0.1%). There were no stastically significant differences (p<0.01) in number of isolated fungi among different plant samples and sampling locations. This is the first detailed study on fungal diversity associated with diseased and healthy A. digitata and S. birrea trees in Kenya and it clearly indicates the need for detailed studies of fungal species isolated to develop mitigation strategies.

scholarly journals Cryphonectriaceae on Myrtales in China: phylogeny, host range, and pathogenicity

2020 ◽  
Vol 45 (1) ◽  
pp. 101-131 ◽  
Author(s):  
W. Wang ◽  
G.Q. Li ◽  
Q.L. Liu ◽  
S.F. Chen
Keyword(s):  
New Species ◽  
Ribosomal Dna ◽  
Dna Sequences ◽  
Fungal Pathogens ◽  
Southern China ◽  
Large Subunit ◽  
Morphological Characteristics ◽  
Psidium Guajava ◽  
Fungal Species ◽  
Canker Disease

Plantation-grown Eucalyptus (Myrtaceae) and other trees residing in the Myrtales have been widely planted in southern China. These fungal pathogens include species of Cryphonectriaceae that are well-known to cause stem and branch canker disease on Myrtales trees. During recent disease surveys in southern China, sporocarps with typical characteristics of Cryphonectriaceae were observed on the surfaces of cankers on the stems and branches of Myrtales trees. In this study, a total of 164 Cryphonectriaceae isolates were identified based on comparisons of DNA sequences of the partial conserved nuclear large subunit (LSU) ribosomal DNA, internal transcribed spacer (ITS) regions including the 5.8S gene of the ribosomal DNA operon, two regions of the β-tubulin (tub2/tub1) gene, and the translation elongation factor1-alpha (tef1) gene region, as well as their morphological characteristics. The results showed that eight species reside in four genera of Cryphonectriaceae occurring on the genera Eucalyptus, Melastoma (Melastomataceae), Psidium (Myrtaceae), Syzygium (Myrtaceae), and Terminalia (Combretaceae) in Myrtales. These fungal species include Chrysoporthe deuterocubensis, Celoporthe syzygii, Cel. eucalypti, Cel. guang-dongensis, Cel. cerciana, a new genus and two new species, as well as one new species of Aurifilum. These new taxa are hereby described as Parvosmorbus gen. nov., Par. eucalypti sp. nov., Par. guangdongensis sp. nov., and Aurifilum terminali sp. nov. Pathogenicity tests showed that the eight species of Cryphonectriaceae are pathogenic to two Eucalyptus hybrid seedlings, Melastoma sanguineum branches, and Psidium guajava and Syzygium jambos seedlings. Theoveralldatashowedthat Chr. deuterocubensis is the most aggressive, followed by Par. eucalypti. Significant differences in tolerance were observed between the two tested Eucalyptus hybrid genotypes, suggesting that disease-tolerant genotypes can be selected for disease management in the Eucalyptus industry.

scholarly journals Naturally-occurring entomopathogenic fungi on three bark beetle species (Coleoptera: Curculionidae) in Bulgaria

2010 ◽  
Vol 25 (1) ◽  
pp. 59-63 ◽  
Author(s):  
Slavimira Draganova ◽  
Danail Takov ◽  
Danail Doychev
Keyword(s):  
Entomopathogenic Fungi ◽  
Bark Beetles ◽  
Fungal Pathogens ◽  
Morphological Characteristics ◽  
Ips Typographus ◽  
Beauveria Brongniartii ◽  
Naturally Occurring ◽  
Fungal Entomopathogens ◽  
Pure Cultures ◽  
Ips Sexdentatus

Bark beetles (Coleoptera: Curculionidae: Scolytinae) belong to one of the most damaging groups of forest insects and the activity of their natural enemies - pathogens, parasitoids, parasites or predators suppressing their population density, is of great importance. Biodiversity of entomopathogenic fungi on bark beetles in Bulgaria has been investigated sporadically. The aim of this preliminary study was to find, identify and study morphological characteristics of fungal entomopathogens naturally-occurring in populations of three curculionid species - Ips sexdentatus Boern, Ips typographus (L.) and Dryocoetes autographus (Ratz.). Dead pest adults were found under the bark of Pinus sylvestris and Picea abies trees collected from forests in the Maleshevska and Vitosha Mountains. Fungal pathogens were isolated into pure cultures on SDAY (Sabouraud dextrose agar with yeast extract) and were identified based on morphological characteristics both on the host and in a culture. Morphological characteristics of the isolates were studied by phenotypic methods. The fungal isolates obtained from dead adults of Ips sexdentatus, Ips typographus and D. autographus were found to belong to the species Beauveria bassiana (Bals. - Criv.) Vuillemin, Beauveria brongniartii (Saccardo) Petch and Isaria farinosa (Holmsk.) Fries (anamorph Ascomycota, Sordariomycetes: Hypocreales, Cordycipitaceae). Morphological traits of the isolates are described.

scholarly journals ISOLATION AND IDENTIFICATION OF PHYTOPATHOGENIC FUNGI FROM INFECTED PLANT PARTS

2018 ◽  
Vol 10 (1) ◽  
pp. 26
Author(s):  
R. Thilagam ◽  
G. Kalaivani ◽  
N. Hemalatha
Keyword(s):  
Infected Plant ◽  
Morphological Characteristics ◽  
Phytopathogenic Fungi ◽  
Malt Extract ◽  
Ear Rot ◽  
Isolation And Identification ◽  
Plant Parts ◽  
Extract Agar ◽  
Cotton Blue ◽  
Pure Cultures

Objective: The present study deals with the isolation and identification of phytopathogenic fungi. The fungal isolates were Alternaria spp (Tomato early blight), Fusarium oxysporum (Fusarium wilt), Fusarium solani (daming off and root rot), Aspergillus flavus (Ear rot) and Collectotricumspp (Anthracnose).Methods: They were isolated from infected plant parts and were identified on the basis of colony morphology andlacto phenol cotton blue (LPCB) stains were used to identifymicroscopic examination of spore structures. Pure cultures of the isolates were sub cultured and transferred onto differential media; potato dextrose agar, malt extract agar, czapek yeast extract agar and czapek dox agar for species identification using macro morphological characteristicsThe morphological characteristics of these fungal elements showed various kinds of spores have been identified up to genus/species level.Results: This study proves rapid and less expensive techniques to validate a primary alarm of contamination.Conclusion: The fivefungus which were isolated from different plant parts were very effective in distruction of the plant and found that the producionwere reduced due to the infection. This rapid and less expensive techniques to validate a primary alarm of contamination.

scholarly journals First Report of Phaeoacremonium inflatipes, P. iranianum, and P. sicilianum Causing Petri Disease of Grapevine in Spain

Plant Disease ◽  
2009 ◽  
Vol 93 (9) ◽  
pp. 964-964 ◽  
Author(s):  
D. Gramaje ◽  
J. Armengol ◽  
M. I. Colino ◽  
R. Santiago ◽  
E. Moralejo ◽  
...  
Keyword(s):  
Morphological Characteristics ◽  
Fungal Species ◽  
Balearic Islands ◽  
Control Treatment ◽  
Malt Extract ◽  
Poor Growth ◽  
First Report ◽  
Petri Disease ◽  
Western Spain ◽  
One Year

In 2008, four isolates of Phaeoacremonium, morphologically and genetically different from known Phaeoacremonium spp. in Spain, were isolated from rootstocks of young grapevine (Vitis vinifera) plants showing Petri disease symptoms including low vigor, reduced foliage, and dark streaking of the xylem in Badajoz Province (western Spain; cv. Syrah on SO4 rootstock), Tarragona Province (eastern Spain; cv. Garnacha on 161 49 C rootstock), and Balearic Islands (eastern Spain; cv. Tempranillo on Rupestris de Lot rootstock). Single-conidial isolates were obtained and grown on potato dextrose agar (PDA) and malt extract agar (MEA) at 25°C for 2 to 3 weeks in the dark until colonies sporulated (3). Identification was based on morphological characteristics (1–3). Phaeoacremonium inflatipes W. Gams, Crous & M. J. Wingf. and P. iranianum L. Mostert, Gräf., W. Gams & Crous were detected in Badajoz Province and P. sicilianum Essakhi, Mugnai, Surico & Crous in Tarragona Province and Balearic Islands. Colonies of P. inflatipes were gray on PDA and gray-brown on MEA. Conidiophores were branched, 15 to 37 (mean 25) μm long. Conidia were hyaline, oblong-ellipsoidal or obovoid, 3 to 5.5 (mean 4) μm long, and 1.2 to 1.9 (mean 1.6) μm wide. Colonies of P. iranianum were brownish gray on PDA and pale brown on MEA. Conidiophores were unbranched and 18 to 47.5 (mean 29) μm long. Conidia were hyaline, oblong-ellipsoidal, 3 to 5 (mean 4) μm long, and 1 to 1.8 (mean 1.5) μm wide. Colonies of P. sicilianum were pale brown on PDA and brown to pale orange on MEA. Conidiophores were branched and 13 to 55 (mean 32.5) μm long. Conidia were hyaline, allantoid, 3 to 8.5 (mean 6) μm long, and 1.5 to 2 (mean 1.8) μm wide. Identity of isolates Pin-2, Pir-4, Psi-1, and Psi-2 was confirmed by sequencing a fragment of the beta-tubulin gene with primers T1 and Bt2b (P. inflatipes, isolate Pin-2: GenBank Accession No. FJ872407, 100% similarity to Accession No. AY579323; P. iranianum, isolate Pir-4: GenBank Accession No. FJ872406, 99% similarity to Accession No. EU128077; P. sicilianum isolates Psi-1 and Psi-2: GenBank Accession Nos. FJ872408 and No. FJ872409, 100% similarity to Accession No. EU863489). Pathogenicity tests were conducted using Pin-2, Pir-4, and Psi-1 isolates. One-year-old callused and rooted cuttings of 110 R rootstock cultivated in sterile peat were wounded at the uppermost internode with an 8-mm cork borer. An 8-mm mycelium plug from a 2-week-old culture was placed into the wound. Wounds were wrapped with Parafilm. Ten cuttings per fungal isolate were used. Ten control plants were inoculated with 8-mm noncolonized PDA plugs. Plants were maintained in a greenhouse at 25°C. Within 2 months, all Phaeoacremonium-inoculated cuttings exhibited shoots with poor growth, small leaves, short internodes, and black streaks in the xylem. The mean shoot weight per plant was 1.8 g in P. inflatipes-inoculated plants, 1.9 g in P. iranianum-inoculated plants, and 1.6 g in P. sicilianum-inoculated plants, all lower than the control treatment (6.8 g). Control plants did not show any symptoms. All fungal species were reisolated from wood of all inoculated cuttings, completing Koch's postulates. Their identity was confirmed with the methods described above. To our knowledge, this is the first report of P. inflatipes, P. iranianum, and P. sicilianum causing Petri disease in Spain. References: (1) P. W. Crous et al. Mycologia 88:786, 1996. (2) S. Essakhi et al. Persoonia 21:119, 2008. (3) L. Mostert et al. Stud. Mycol. 54:1, 2006.

scholarly journals Post-translational regulation of autophagy is involved in intra-microbiome suppression of fungal pathogens

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jing Wang ◽  
Chaoyun Xu ◽  
Qiming Sun ◽  
Jinrong Xu ◽  
Yunrong Chai ◽  
...  
Keyword(s):  
Translational Regulation ◽  
Fungal Pathogens ◽  
Fungal Growth ◽  
Fungal Species ◽  
26S Proteasome ◽  
Healthy Plant ◽  
Autophagy Induction ◽  
Histone Acetyltransferase Gcn5 ◽  
Plant Microbiota ◽  
Autophagic Process

Abstract Background Microbiome interactions are important determinants for ecosystem functioning, stability, and health. In previous studies, it was often observed that bacteria suppress potentially pathogenic fungal species that are part of the same plant microbiota; however, the underlying microbe-microbe interplay remains mostly elusive. Here, we explored antagonistic interactions of the fungus Fusarium graminearum and bacterium Streptomyces hygroscopicus at the molecular level. Both are ubiquitous members of the healthy wheat microbiota; under dysbiosis, the fungus causes devastating diseases. Results In co-cultures, we found that Streptomyces alters the fungal acetylome leading to substantial induction of fungal autophagy. The bacterium secrets rapamycin to inactivate the target of rapamycin (TOR), which subsequently promotes the degradation of the fungal histone acetyltransferase Gcn5 through the 26S proteasome. Gcn5 negatively regulates fungal autophagy by acetylating the autophagy-related protein Atg8 at the lysine site K13 and blocking cellular relocalization of Atg8. Thus, degradation of Gcn5 triggered by rapamycin was found to reduce Atg8 acetylation, resulting in autophagy induction in F. graminearum. Conclusions Autophagy homeostasis plays an essential role in fungal growth and competition, as well as for virulence. Our work reveals a novel post-translational regulation of autophagy initiated by a bacterial antibiotic. Rapamycin was shown to be a powerful modulator of bacteria–fungi interactions with potential importance in explaining microbial homeostasis in healthy plant microbiomes. The autophagic process provides novel possibilities and targets to biologically control pathogens.

scholarly journals The Role of Fungi in the Cocoa Production Chain and the Challenge of Climate Change

2021 ◽  
Vol 7 (3) ◽  
pp. 202
Author(s):  
Johannes Delgado-Ospina ◽  
Junior Bernardo Molina-Hernández ◽  
Clemencia Chaves-López ◽  
Gianfranco Romanazzi ◽  
Antonello Paparella
Keyword(s):  
Climate Change ◽  
Fungal Infections ◽  
Close Association ◽  
Pathogenic Fungi ◽  
Fungal Species ◽  
Mitigation Strategies ◽  
Plant Diseases ◽  
Production Chain ◽  
Cocoa Production

Background: The role of fungi in cocoa crops is mainly associated with plant diseases and contamination of harvest with unwanted metabolites such as mycotoxins that can reach the final consumer. However, in recent years there has been interest in discovering other existing interactions in the environment that may be beneficial, such as antagonism, commensalism, and the production of specific enzymes, among others. Scope and approach: This review summarizes the different fungi species involved in cocoa production and the cocoa supply chain. In particular, it examines the presence of fungal species during cultivation, harvest, fermentation, drying, and storage, emphasizing the factors that possibly influence their prevalence in the different stages of production and the health risks associated with the production of mycotoxins in the light of recent literature. Key findings and conclusion: Fungi associated with the cocoa production chain have many different roles. They have evolved in a varied range of ecosystems in close association with plants and various habitats, affecting nearly all the cocoa chain steps. Reports of the isolation of 60 genera of fungi were found, of which only 19 were involved in several stages. Although endophytic fungi can help control some diseases caused by pathogenic fungi, climate change, with increased rain and temperatures, together with intensified exchanges, can favour most of these fungal infections, and the presence of highly aggressive new fungal genotypes increasing the concern of mycotoxin production. For this reason, mitigation strategies need to be determined to prevent the spread of disease-causing fungi and preserve beneficial ones.

scholarly journals Development of a Co-Dominant Cleaved Amplified Polymorphic Sequences Assay for the Rapid Detection and Differentiation of Two Pathogenic Clarireedia spp. Associated with Dollar Spot in Turfgrass

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1489
Author(s):  
Tammy Stackhouse ◽  
Sumyya Waliullah ◽  
Alfredo D. Martinez-Espinoza ◽  
Bochra Bahri ◽  
Emran Ali
Keyword(s):  
Pcr Primers ◽  
The United States ◽  
Fungal Species ◽  
Dollar Spot ◽  
Direct Pcr ◽  
Specific Pcr ◽  
Specificity And Sensitivity ◽  
Pure Cultures ◽  
Speed Up ◽  
Cleaved Amplified Polymorphic Sequences

Dollar spot is one of the most destructive diseases in turfgrass. The causal agents belong to the genus Clarireedia, which are known for causing necrotic, sunken spots in turfgrass that coalesce into large damaged areas. In low tolerance settings like turfgrass, it is of vital importance to rapidly detect and identify the pathogens. There are a few methods available to identify the genus Clarireedia, but none of those are rapid enough and characterize down to the species level. This study produced a co-dominant cleaved amplified polymorphic sequences (CAPS) test that differentiates between C. jacksonii and C. monteithiana, the two species that cause dollar spot disease within the United States. The calmodulin gene (CaM) was targeted to generate Clarireedia spp. specific PCR primers. The CAPS assay was optimized and tested for specificity and sensitivity using DNA extracted from pure cultures of two Clarireedia spp. and other closely related fungal species. The results showed that the newly developed primer set could amplify both species and was highly sensitive as it detected DNA concentrations as low as 0.005 ng/µL. The assay was further validated using direct PCR to speed up the diagnosis process. This drastically reduces the time needed to identify the dollar spot pathogens. The resulting assay could be used throughout turfgrass settings for a rapid and precise identification method in the US.

scholarly journals Mitotic Recombination and Adaptive Genomic Changes in Human Pathogenic Fungi

Genes ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 901 ◽  
Author(s):  
Asiya Gusa ◽  
Sue Jinks-Robertson
Keyword(s):  
Fungal Pathogens ◽  
Repetitive Sequences ◽  
Pathogenic Fungi ◽  
Genetic Alterations ◽  
Fungal Species ◽  
Chronic Infections ◽  
Yeast Saccharomyces Cerevisiae ◽  
Genomic Changes ◽  
Break Site ◽  
Repair Mechanisms

Genome rearrangements and ploidy alterations are important for adaptive change in the pathogenic fungal species Candida and Cryptococcus, which propagate primarily through clonal, asexual reproduction. These changes can occur during mitotic growth and lead to enhanced virulence, drug resistance, and persistence in chronic infections. Examples of microevolution during the course of infection were described in both human infections and mouse models. Recent discoveries defining the role of sexual, parasexual, and unisexual cycles in the evolution of these pathogenic fungi further expanded our understanding of the diversity found in and between species. During mitotic growth, damage to DNA in the form of double-strand breaks (DSBs) is repaired, and genome integrity is restored by the homologous recombination and non-homologous end-joining pathways. In addition to faithful repair, these pathways can introduce minor sequence alterations at the break site or lead to more extensive genetic alterations that include loss of heterozygosity, inversions, duplications, deletions, and translocations. In particular, the prevalence of repetitive sequences in fungal genomes provides opportunities for structural rearrangements to be generated by non-allelic (ectopic) recombination. In this review, we describe DSB repair mechanisms and the types of resulting genome alterations that were documented in the model yeast Saccharomyces cerevisiae. The relevance of similar recombination events to stress- and drug-related adaptations and in generating species diversity are discussed for the human fungal pathogens Candida albicans and Cryptococcus neoformans.

scholarly journals Eutypella parasitica and Other Frequently Isolated Fungi in Wood of Dead Branches of Young Sycamore Maple (Acer pseudoplatanus) in Slovenia

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 467 ◽  
Author(s):  
Ana Brglez ◽  
Barbara Piškur ◽  
Nikica Ogris
Keyword(s):  
Species Diversity ◽  
Fungal Community ◽  
Sampling Site ◽  
Outer Part ◽  
Similarity Index ◽  
Asymptomatic Infection ◽  
Fungal Species ◽  
Acer Pseudoplatanus ◽  
Pure Cultures ◽  
Sycamore Maple

Eutypella parasitica R.W. Davidson and R.C. Lorenz is the causative agent of Eutypella canker of maple, a destructive disease of maples in Europe and North America. The fungus E. parasitica infects the trunk through a branch stub or bark wound. Because the fungal community may have an impact on infection and colonization by E. parasitica, the composition of fungi colonizing wood of dead branches of sycamore maple (Acer pseudoplatanus L.) was investigated in five sampling sites in Slovenia. Forty samples from each sampling site were collected between the November 2017 and March 2018 period. Isolations were made from the wood in the outer part of dead branches and from discoloured wood in the trunk that originated from a dead branch. Pure cultures were divided into morphotypes, and one representative culture per morphotype was selected for further molecular identification. From a total of 2700 cultured subsamples, 1744 fungal cultures were obtained, which were grouped into 212 morphotypes. The investigated samples were colonized by a broad spectrum of fungi. The most frequently isolated species were Eutypa maura (Fr.) Sacc., Eutypa sp. Tul. and C. Tul., Fusarium avenaceum (Fr.) Sacc., Neocucurbitaria acerina Wanas., Camporesi, E.B.G. Jones and K.D. Hyde and E. parasitica. In this study, we distinguished species diversity and the fungal community. There were no significant differences in the diversity of fungal species between the five sampling sites, and branch thickness did not prove to be a statistically significant factor in fungal species diversity. Nevertheless, relatively low Jaccard similarity index values suggested possible differences in the fungal communities from different sampling sites. This was confirmed by an analysis of similarities, which showed that the isolated fungal community distinctly differed between the five sampling sites and between the different isolation sources. Eutypella parasitica was isolated from all five investigated sampling sites, although Eutypella cankers were observed in only three sampling sites, indicating the possibility of asymptomatic infection.

Sign in / Sign up

Export Citation Format

Share Document