scholarly journals Identification of New Fungal Pathogens of Coast Live Oak in California

Plant Disease ◽  
2013 ◽  
Vol 97 (8) ◽  
pp. 1025-1036 ◽  
Author(s):  
Shannon Colleen Lynch ◽  
Paul J. Zambino ◽  
Joey Sal Mayorquin ◽  
Danny Ho Wang ◽  
Akif Eskalen
Keyword(s):  
Fungal Pathogens ◽  
Southern California ◽  
Phylogenetic Analyses ◽  
Ribosomal Subunit ◽  
Complete Sequence ◽  
Fungal Species ◽  
Pathogenicity Test ◽  
Live Oak ◽  
Unknown Species ◽  
One Year

A decline of coast live oak (Quercus agrifolia) has been observed throughout southern California. In this study, the identity and pathogenicity of non-Botryosphaeriaceae fungal species consistently recovered from necrotic tissues of branch and bleeding trunk canker samples from these locations were assessed. Species were identified morphologically and by comparison of the complete sequence of the internal transcribed spacer (ITS) of the ribosomal DNA to sequences available in GenBank. Phylogenetic analyses were then conducted using ITS and partial sequences of the β-tubulin and mitochondrial small ribosomal subunit genes for unknown species. Fungi recovered and identified included Fusarium solani, Phaeoacremonium mortoniae, Diatrypella verrucaeformis, and a fungus described herein as Cryptosporiopsis querciphila sp. nov. One-year-old coast live oak seedlings were wound inoculated under controlled conditions to test pathogenicity of the fungal species. Each fungal species was successfully reisolated from necrotic tissue at 70 and 100% for P. mortoniae and all other species, and xylem necrosis was significantly different between all treatments and controls (P < 0.0001 at α = 0.05). Isolates of F. solani were the most aggressive tested. These species represent new records of fungal pathogens of coast live oak in California. Results from the pathogenicity test suggest that these fungi play a role in the decline of southern California coast live oak trees.

scholarly journals Identification and Pathogenicity of Fungal Pathogens Associated with Stem-End Rot of Avocado in California

Plant Disease ◽  
2013 ◽  
Vol 97 (12) ◽  
pp. 1580-1584 ◽  
Author(s):  
M. Twizeyimana ◽  
H. Förster ◽  
V. McDonald ◽  
D. H. Wang ◽  
J. E. Adaskaveg ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Southern California ◽  
Colletotrichum Gloeosporioides ◽  
Fungal Species ◽  
Molecular Techniques ◽  
Pathogenicity Test ◽  
Avocado Fruit ◽  
Low Humidity ◽  
Neofusicoccum Luteum

Stem-end rot of harvested avocado fruit commonly occurs wherever the crop is cultivated. Multiple fungal species have been described as causal agents. To determine the causal pathogens of stem-end rot in California, fungal isolations were conducted from symptomatic fruit, and fungi were identified by morphological and molecular techniques. In 2010 and 2011, a total of 177 isolates were recovered from 290 avocado fruit collected from seven orchards in one of the major avocado growing areas in Southern California. The majority of isolates was identified as Neofusicoccum luteum (65%), with the remainder either as Colletotrichum gloeosporioides (33%) or Phomopsis sp. (2%). In a pathogenicity test, N. luteum caused significantly (P < 0.05) more severe stem-end rot than either C. gloeosporioides or Phomopsis sp. No significant (P > 0.05) differences in stem-end rot severity were observed between inoculations with N. luteum isolated from fruit stem-end rot and N. luteum or N. parvum isolated from branch cankers. This confirms that stem-end rot of avocado can be initiated by fungi causing branch cankers. Although low humidity and rainfall during much of the growing and harvest seasons in California are considered unfavorable conditions for the development of avocado stem-end rot, the identification of the causal pathogens is of value when decays have to be managed during outbreaks, and it stresses the importance of managing branch cankers.

scholarly journals A Novel Phellinidium sp. Causes Laminated Root Rot on Qilian Juniper (Sabina przewalskii) in Northwest China

Plant Disease ◽  
2015 ◽  
Vol 99 (1) ◽  
pp. 39-43 ◽  
Author(s):  
Bao-Kai Cui ◽  
Yu-Cheng Dai ◽  
Shuang-Hui He ◽  
Li-Wei Zhou ◽  
Hai-Sheng Yuan
Keyword(s):  
Root Rot ◽  
Phylogenetic Analyses ◽  
Northwest China ◽  
Morphological Characters ◽  
Fungal Species ◽  
Qinghai Province ◽  
Forest Pathogen ◽  
Sabina Przewalskii ◽  
Qilian Juniper ◽  
One Year

A laminated root rot on Qilian juniper (Sabina przewalskii) caused by a species of Phellinidium (Basidiomycota) was observed in northwest China. Seventeen fungal samples collected from Qinghai Province during 2012 and 2013 were used for taxonomic and pathogenicity tests. The fungal pathogen was identified by morphological characters and phylogenetic analyses based on nLSU sequences. A new fungus is described herein as Phellinidium qilianense sp. nov. One-year-old Qilian juniper seedlings were wound-inoculated under controlled conditions to test pathogenicity of the fungal species. The fungus was successfully reisolated from decayed tissue of tested seedlings. P. qilianense is a new forest pathogen on coniferous trees in China.

scholarly journals Identification of Species of Botryosphaeriaceae Causing Bot Gummosis in Citrus in California

Plant Disease ◽  
2014 ◽  
Vol 98 (1) ◽  
pp. 55-61 ◽  
Author(s):  
A. O. Adesemoye ◽  
J. S. Mayorquin ◽  
D. H. Wang ◽  
M. Twizeyimana ◽  
S. C. Lynch ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Elongation Factor ◽  
Complete Sequence ◽  
Fungal Species ◽  
Lesion Length ◽  
Neoscytalidium Dimidiatum ◽  
Phylogenetic Comparison ◽  
Identification Of Species ◽  
Multigene Phylogenetic Analysis ◽  
Factor Α

Members of the Botryosphaeriaceae family are known to cause Bot gummosis on many woody plants worldwide. To identify pathogens associated with Bot gummosis on citrus in California, scion and rootstock samples were collected in 2010 and 2011 from five citrus-growing counties in California. Symptoms observed on citrus included branch cankers, dieback, and gumming. Various fungal species were recovered from necrotic tissues of branch canker and rootstock samples. Species were identified morphologically and by phylogenetic comparison as ‘Eureka’ lemon, ‘Valencia’, ‘Washington Navel’, ‘Fukumoto’, grapefruit, ‘Satsuma’, and ‘Meyer’ lemon. Species were identified morphologically and by phylogenetic comparison of the complete sequence of the internal transcribed spacer regions, β-tubulin gene, and elongation factor α-1 genes with those of other species in GenBank. A consensus-unrooted most parsimonious tree resulting from multigene phylogenetic analysis showed the existence of three major clades in the Botryosphaeriaceae family. In total, 74 isolates were identified belonging to the Botryosphaeriaceae family, with Neofusicoccum spp., Dothiorella spp., Diplodia spp., (teleomorph Botryosphaeria), Lasiodiplodia spp., and Neoscytalidium dimidiatum (teleomorphs unknown) accounting for 39, 25, 23, 10, and 3% of the total, respectively. On inoculated Eureka lemon shoots, lesion length was significantly different (P < 0.05) among 14 isolates recovered from portions of cankered tissues of the original trees. Lesion lengths were significantly longer (P < 0.05) for shoots inoculated with isolates of Neofusicoccum luteum and shorter for shoots inoculated with isolates of Dothiorella viticola (P < 0.05) than those of other species. Identifying the distribution and occurrence of these fungal pathogens associated with Bot gummosis is useful for management applications during occasional outbreaks in California.

scholarly journals Year-to-Year Incidence of Cranberry Fruit Rot and Persistence of Fungal Pathogens

2017 ◽  
Vol 18 (2) ◽  
pp. 114-119 ◽  
Author(s):  
Lindsay D. Wells-Hansen ◽  
Patricia S. McManus
Keyword(s):  
New Jersey ◽  
Fungal Pathogens ◽  
Field Studies ◽  
Fungal Species ◽  
Fruit Rot ◽  
Economic Losses ◽  
Current Management ◽  
Consistent Basis ◽  
One Year ◽  
Management Recommendations

Cranberry fruit rot is a disease complex comprised of as many as 15 fungal species. Current management recommendations are to spray broad-spectrum fungicides every year in regions such as New Jersey where fruit rot incidence is high on a consistent basis. By contrast, in regions such as Wisconsin, where economic losses from fruit rot occur sporadically, many growers forego fungicide sprays, but if faced with a serious fruit rot outbreak they then spray fungicides intensively the following year to prevent a recurrence of disease. This recommendation is based on the untested assumption that left unchecked, fruit rot incidence will increase and that the predominant fruit rot pathogens will persist from one year to the next. Field studies conducted over 3 years showed that in New Jersey fruit rot incidence increased or remained high and fruit rot pathogens persisted from one year to the next. By contrast, in Wisconsin fruit rot incidence decreased or remained low, and the persistence of pathogens was inconsistent from one year to the next. Thus, in Wisconsin, fruit rot incidence and fungal species present in one year do not reliably predict the disease situation in the following year, a finding that should be considered when planning fungicide spray programs.

Plenodomus dezfulensis sp. nov. causing leaf spot of Rapeseed in Iran

Phytotaxa ◽  
2021 ◽  
Vol 523 (2) ◽  
pp. 141-154
Author(s):  
ATENA SAFI ◽  
MEHDI MEHRABI-KOUSHKI ◽  
REZA FAROKHINEJAD
Keyword(s):  
Rna Polymerase Ii ◽  
Leaf Spot ◽  
Internal Transcribed Spacer ◽  
Phylogenetic Analyses ◽  
Fungal Species ◽  
Nuclear Ribosomal Dna ◽  
Pathogenicity Test ◽  
Molecular Phylogenetic ◽  
Southwestern Iran ◽  
Combined Matrix

Rapeseed (Brassica napus subsp. napus) is one of the autumn crops in Iran. A new fungal species isolated from internal tissues associating a typical leaf spot of Rapeseed in Dezful (southwestern Iran) was described and illustrated. The sampling and isolation were performed in the late fall of 2019 (during December), which led to obtain the colonies with the similar morphology. Molecular phylogenetic analyses based on a combined matrix of the internal transcribed spacer regions 1 and 2 including the intervening 5.8S nuclear ribosomal DNA (ITS), and partial regions of the β-tubulin (tub2) and RNA polymerase II second largest subunit (rpb2) indicated that two isolated strains represent a new Plenodomus species in family Leptosphaeriaceae (Pleosporales). These novel strains formed a sister lineage with P. biglobosus in our phylogenetic analyses, while, observed morphology is distinguished the taxa from P. biglobosus by its pycnidia in having hyphal outgrowths and lacking cylindrical neck. Accordingly, P. dezfulensis sp. nov. was introduced and its pathogenicity was investigated. Pathogenicity test with both P. dezfulensis strains on three-week seedlings of Rapeseed reproduced leaf spot symptoms. These results approve P. dezfulensis as the causal agent of leaf spot observed on Rapeseed in Dezful.

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 Multilocus phylogenies reveal three new truffle-like taxa and the traces of interspecific hybridization in Octaviania (Boletaceae, Boletales)

IMA Fungus ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Takamichi Orihara ◽  
Rosanne Healy ◽  
Adriana Corrales ◽  
Matthew E. Smith
Keyword(s):  
Rna Polymerase Ii ◽  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Gene Tree ◽  
Phylogenetic Network ◽  
Elongation Factor ◽  
Morphological Observation ◽  
Tree Comparison ◽  
Unknown Species ◽  
The Usa

ABSTRACTAmong many convergently evolved sequestrate fungal genera in Boletaceae (Boletales, Basidiomycota), the genus Octaviania is the most diverse. We recently collected many specimens of Octaviania subg. Octaviania, including several undescribed taxa, from Japan and the Americas. Here we describe two new species in subgenus Octaviania, O. tenuipes and O. tomentosa, from temperate to subtropical evergreen Fagaceae forests in Japan based on morphological observation and robust multilocus phylogenetic analyses (nrDNA ITS and partial large subunit [LSU], translation elongation factor 1-α gene [TEF1] and the largest subunit of RNA polymerase II gene [RPB1]). Based on specimens from the Americas as well as studies of the holotype, we also taxonomically re-evaluate O. asterosperma var. potteri. Our analysis suggests that O. asterosperma var. potteri is a distinct taxon within the subgenus Octaviania so we recognize this as O. potteri stat. nov. We unexpectedly collected O. potteri specimens from geographically widespread sites in the USA, Japan and Colombia. This is the first verified report of Octaviania from the South American continent. Our molecular analyses also revealed that the RPB1 sequence of one O. tenuipes specimen was identical to that of a closely related species, O. japonimontana, and that one O. potteri specimen from Minnesota had an RPB1 sequence of an unknown species of O. subg. Octaviania. Additionally, one O. japonimontana specimen had an unusually divergent TEF1 sequence. Gene-tree comparison and phylogenetic network analysis of the multilocus dataset suggest that these heterogenous sequences are most likely the result of previous inter- and intra-specific hybridization. We hypothesize that frequent hybridization events in Octaviania may have promoted the high genetic and species diversity found within the genus.

scholarly journals Production of Phytotoxic Metabolites by Botryosphaeriaceae in Naturally Infected and Artificially Inoculated Grapevines

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 802
Author(s):  
Pierluigi Reveglia ◽  
Regina Billones-Baaijens ◽  
Jennifer Millera Millera Niem ◽  
Marco Masi ◽  
Alessio Cimmino ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Protocatechuic Acid ◽  
Physiological Factors ◽  
Diplodia Seriata ◽  
Grapevine Trunk Diseases ◽  
Botryosphaeria Dieback ◽  
Trunk Diseases ◽  
One Year ◽  
Pathogen Dna

Grapevine trunk diseases (GTDs) are considered a serious problem to viticulture worldwide. Several GTD fungal pathogens produce phytotoxic metabolites (PMs) that were hypothesized to migrate to the foliage where they cause distinct symptoms. The role of PMs in the expression of Botryosphaeria dieback (BD) symptoms in naturally infected and artificially inoculated wood using molecular and analytical chemistry techniques was investigated. Wood samples from field vines naturally infected with BD and one-year-old vines inoculated with Diplodia seriata, Spencermartinsia viticola and Dothiorella vidmadera were analysed by cultural isolations, quantitative PCR (qPCR) and targeted LC-MS/MS to detect three PMs: (R)-mellein, protocatechuic acid and spencertoxin. (R)-mellein was detected in symptomatic naturally infected wood and vines artificially inoculated with D. seriata but was absent in all non-symptomatic wood. The amount of (R)-mellein detected was correlated with the amount of pathogen DNA detected by qPCR. Protocatechuic acid and spencertoxin were absent in all inoculated wood samples. (R)-mellein may be produced by the pathogen during infection to break down the wood, however it was not translocated into other parts of the vine. The foliar symptoms previously reported in vineyards may be due to a combination of PMs produced and climatic and physiological factors that require further investigation.

scholarly journals Morpho-molecular identification and first report of Fusarium equiseti in causing chilli wilt from Kashmir (Northern Himalayas)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ammarah Hami ◽  
Rovidha S. Rasool ◽  
Nisar A. Khan ◽  
Sheikh Mansoor ◽  
Mudasir A. Mir ◽  
...  
Keyword(s):  
Dna Barcoding ◽  
Pcr Amplification ◽  
Its Region ◽  
Fungal Species ◽  
Pathogenicity Test ◽  
Kashmir Valley ◽  
Fusarium Equiseti ◽  
Infected Root ◽  
Fusarium Sp ◽  
High Degree

AbstractChilli (Capsicum annuum L.) is one of the most significant vegetable and spice crop. Wilt caused by Fusarium Sp. has emerged as a serious problem in chilli production. Internal transcribed spacer (ITS) region is widely used as a DNA barcoding marker to characterize the diversity and composition of Fusarium communities. ITS regions are heavily used in both molecular methods and ecological studies of fungi, because of its high degree of interspecific variability, conserved primer sites and multiple copy nature in the genome. In the present study we focused on morphological and molecular characterization of pathogen causing chilli wilt. Chilli plants were collected from four districts of Kashmir valley of Himalayan region. Pathogens were isolated from infected root and stem of the plants. Isolated pathogens were subjected to DNA extraction and PCR amplification. The amplified product was sequenced and three different wilt causing fungal isolates were obtained which are reported in the current investigation. In addition to Fusarium oxysporum and Fusarium solani, a new fungal species was found in association with the chilli wilt in Kashmir valley viz., Fusarium equiseti that has never been reported before from this region. The studies were confirmed by pathogenicity test and re-confirmation by DNA barcoding.

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.

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