scholarly journals Podosphaera spiraeae (Japanese spiraea powdery mildew).

2021 ◽  
Author(s):  
Swarnalatha Moparthi ◽  
Michael Bradshaw
Keyword(s):  
Powdery Mildew ◽  
Pest Management ◽  
Fungal Pathogen ◽  
Host Plants ◽  
Pathogenic Fungus ◽  
Wind Dispersal ◽  
Primary Control ◽  
Long Distance ◽  
Management Regimes ◽  
Leaf Drop

Abstract Podosphaera spiraeae is a common fungal pathogen for plants in the genus Spiraea. The pathogen is native to Japan but is most likely widespread throughout the temperate world where viable host plants occur. Identification of powdery mildew on Spiraea spp. can be difficult and its occurrence has not been well documented. Wind dispersal of asexual spores, known as conidia, spreads powdery mildew between viable host plants. The most likely long-distance pathway of invasion is through the nursery industry, which commonly trades Spiraea plants. P. spiraeae can be detrimental to nursery growers as it is unsightly, reduces photosynthesis and flower vigour and causes premature leaf drop. Primary control of the pathogenic fungus requires intricate integrated pest management regimes.

Podosphaera spiraeae (Japanese spiraea powdery mildew).

2021 ◽  
Author(s):  
Swarnalatha Moparthi ◽  
Michael Bradshaw
Keyword(s):  
Powdery Mildew ◽  
Pest Management ◽  
Fungal Pathogen ◽  
Host Plants ◽  
Pathogenic Fungus ◽  
Wind Dispersal ◽  
Primary Control ◽  
Long Distance ◽  
Management Regimes ◽  
Leaf Drop

Abstract Podosphaera spiraeae is a common fungal pathogen for plants in the genus Spiraea. The pathogen is native to Japan but is most likely widespread throughout the temperate world where viable host plants occur. Identification of powdery mildew on Spiraea spp. can be difficult and its occurrence has not been well documented. Wind dispersal of asexual spores, known as conidia, spreads powdery mildew between viable host plants. The most likely long-distance pathway of invasion is through the nursery industry, which commonly trades Spiraea plants. P. spiraeae can be detrimental to nursery growers as it is unsightly, reduces photosynthesis and flower vigour and causes premature leaf drop. Primary control of the pathogenic fungus requires intricate integrated pest management regimes.

scholarly journals Ammonia Production by Streptomyces Symbionts of Acromyrmex Leaf-Cutting Ants Strongly Inhibits the Fungal Pathogen Escovopsis

2021 ◽  
Vol 9 (8) ◽  
pp. 1622
Author(s):  
Basanta Dhodary ◽  
Dieter Spiteller
Keyword(s):  
Fungal Pathogen ◽  
Closed Loop ◽  
Pathogenic Fungus ◽  
Ant Colonies ◽  
Strong Activity ◽  
Streptomyces Sp ◽  
Mutualistic Symbiosis ◽  
Leaf Cutting ◽  
Leucoagaricus Gongylophorus ◽  
Production Of Ammonia

Leaf-cutting ants live in mutualistic symbiosis with their garden fungus Leucoagaricus gongylophorus that can be attacked by the specialized pathogenic fungus Escovopsis. Actinomyces symbionts from Acromyrmex leaf-cutting ants contribute to protect L. gongylophorus against pathogens. The symbiont Streptomyces sp. Av25_4 exhibited strong activity against Escovopsis weberi in co-cultivation assays. Experiments physically separating E. weberi and Streptomyces sp. Av25_4 allowing only exchange of volatiles revealed that Streptomyces sp. Av25_4 produces a volatile antifungal. Volatile compounds from Streptomyces sp. Av25_4 were collected by closed loop stripping. Analysis by NMR revealed that Streptomyces sp. Av25_4 overproduces ammonia (up to 8 mM) which completely inhibited the growth of E. weberi due to its strong basic pH. Additionally, other symbionts from different Acromyrmex ants inhibited E. weberi by production of ammonia. The waste of ca. one third of Acomyrmex and Atta leaf-cutting ant colonies was strongly basic due to ammonia (up to ca. 8 mM) suggesting its role in nest hygiene. Not only complex and metabolically costly secondary metabolites, such as polyketides, but simple ammonia released by symbionts of leaf-cutting ants can contribute to control the growth of Escovopsis that is sensitive to ammonia in contrast to the garden fungus L. gongylophorus.

scholarly journals Ampelomyces strains isolated from diverse powdery mildew hosts in Japan: Their phylogeny and mycoparasitic activity, including timing and quantifying mycoparasitism of Pseudoidium neolycopersici on tomato

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251444
Author(s):  
Márk Z. Németh ◽  
Yuusaku Mizuno ◽  
Hiroki Kobayashi ◽  
Diána Seress ◽  
Naruki Shishido ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Host Plants ◽  
Morphological Characteristics ◽  
Post Inoculation ◽  
Powdery Mildew Fungus ◽  
Rdna Its ◽  
Pseudoidium Neolycopersici ◽  
Tomato Powdery Mildew ◽  
Internal Transcribed Spacer Rdna ◽  
Complete Collapse

A total of 26 Ampelomyces strains were isolated from mycelia of six different powdery mildew species that naturally infected their host plants in Japan. These were characterized based on morphological characteristics and sequences of ribosomal DNA internal transcribed spacer (rDNA-ITS) regions and actin gene (ACT) fragments. Collected strains represented six different genotypes and were accommodated in three different clades of the genus Ampelomyces. Morphology of the strains agreed with that of other Ampelomyces strains, but none of the examined characters were associated with any groups identified in the genetic analysis. Five powdery mildew species were inoculated with eight selected Ampelomyces strains to study their mycoparasitic activity. In the inoculation experiments, all Ampelomyces strains successfully infected all tested powdery mildew species, and showed no significant differences in their mycoparasitic activity as determined by the number of Ampelomyces pycnidia developed in powdery mildew colonies. The mycoparasitic interaction between the eight selected Ampelomyces strains and the tomato powdery mildew fungus (Pseudoidium neolycopersici strain KTP-03) was studied experimentally in the laboratory using digital microscopic technologies. It was documented that the spores of the mycoparasites germinated on tomato leaves and their hyphae penetrated the hyphae of Ps. neolycopersici. Ampelomyces hyphae continued their growth internally, which initiated the atrophy of the powdery mildew conidiophores 5 days post inoculation (dpi); caused atrophy 6 dpi; and complete collapse of the parasitized conidiphores 7 dpi. Ampelomyces strains produced new intracellular pycnidia in Ps. neolycopersici conidiophores ca. 8–10 dpi, when Ps. neolycopersici hyphae were successfully destroyed by the mycoparasitic strain. Mature pycnidia released spores ca. 10–14 dpi, which became the sources of subsequent infections of the intact powdery mildew hyphae. Mature pycnidia contained each ca. 200 to 1,500 spores depending on the mycohost species and Ampelomyces strain. This is the first detailed analysis of Ampelomyces strains isolated in Japan, and the first timing and quantification of mycoparasitism of Ps. neolycopersici on tomato by phylogenetically diverse Ampelomyces strains using digital microscopic technologies. The developed model system is useful for future biocontrol and ecological studies on Ampelomyces mycoparasites.

scholarly journals IDENTIFIKASI DAN UJI PATOGENISITAS CENDAWAN ENTOMOPATOGEN LOKAL TERHADAP Leptocorisa oratorius

EUGENIA ◽  
2011 ◽  
Vol 17 (3) ◽  
Author(s):  
Emmy Senewe ◽  
Guntur Manengkey
Keyword(s):  
Fungal Pathogen ◽  
Fungal Pathogens ◽  
Pathogenic Fungus ◽  
Pathogenic Fungi ◽  
North Sulawesi ◽  
Pathogenicity Tests ◽  
Major Pest ◽  
White Mycelium ◽  
Fusarium Sp ◽  
Leptocorisa Oratorius

ABSTRACT Leptocorisa oratorius is one major pest of rice in North Sulawesi. Hence, it is necessary to control the pest. The research objective was to identify and to test pathogenicity of local  entomopathogen fungi which infected  Leptocorisa oratorius. The pathogens were collected through sampling of L. oratorius which had been infected by the fungi in the field. The pathogenic fungi was isolated using PDA medium, identified followed by inoculation for pathogenecity test.  During several sampling pest, it was found that  L. oratorius was attacked by fungal pathogens in the field. The identification revelead that the fungal pathogens were Beauveria sp and Fusarium sp. Both the fungal pathogen produced white mycelium and could only be distinguished using microscope in the laboratory. Result of pathogenicity tests showed that the two fungal pathogens caused different mortality of the L. oratorius. Mortality of  L. oratorius caused by pathogenic fungus Beauveria sp was  30.3% . Whereas, mortality of  L. oratorius caused by Fusarium sp was only 3.33%. Keywords : pathogenic fungi, entomopathogen, pathogenicity tests, L. oratorius

scholarly journals De novo indol‐3‐ylmethyl glucosinolate biosynthesis, and not long‐distance transport, contributes to defence of Arabidopsis against powdery mildew

2020 ◽  
Vol 43 (6) ◽  
pp. 1571-1583 ◽  
Author(s):  
Pascal Hunziker ◽  
Hassan Ghareeb ◽  
Lena Wagenknecht ◽  
Christoph Crocoll ◽  
Barbara Ann Halkier ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
De Novo ◽  
Long Distance ◽  
Glucosinolate Biosynthesis ◽  
Long Distance Transport ◽  
Distance Transport

Long-distance wind dispersal of tree seeds

1995 ◽  
Vol 73 (7) ◽  
pp. 1036-1045 ◽  
Author(s):  
D. F. Greene ◽  
E. A. Johnson
Keyword(s):  
Seed Dispersal ◽  
Conservation Biology ◽  
Plant Conservation ◽  
Dispersal Distance ◽  
Wind Dispersal ◽  
Source Strength ◽  
Long Distance ◽  
Model Predictions ◽  
Tree Seeds ◽  
The Relationship

Long-distance seed dispersal figures prominently in most plant conservation biology arguments, yet we possess little more than anecdotes concerning the relationship among deposition (seeds/m2), source strength (seeds/m2), and distance. In this paper we derive two simple models for long-distance deposition. The models are tested at the scale of 100–1600 m from the source and found to be within 5-fold of the observed deposition. There is no discernable decline in deposition for the range 300–1600 m. While we hesitate to extend model predictions to greater distances, both the models and the empirical results allow us to assert that rare wind-dispersed species in woodlots (dispersal distance around 1 km) are effectively isolated from one another at the temporal scale of 1000 years. Key words: plant conservation biology, wind dispersal of seeds, metapopulations.

scholarly journals Key scale insects (Hemiptera: Coccoidea) of high economic importance in a Mediterranean area: host plants, bio-ecological characteristics, natural enemies and pest management strategies – a review

2017 ◽  
Vol 53 (No. 1) ◽  
pp. 1-14 ◽  
Author(s):  
Mansour Ramzi ◽  
Grissa-Lebdi Kaouthar ◽  
Suma Pompeo ◽  
Mazzeo Gaetana ◽  
Russo Agatino
Keyword(s):  
Pest Management ◽  
Host Plants ◽  
Management Strategies ◽  
Mediterranean Area ◽  
Economic Importance ◽  
Scale Insects ◽  
Economic Losses ◽  
Planococcus Citri ◽  
Present Contribution ◽  
Saissetia Oleae

Key scale insects that have long been considered as having high economic importance in Tunisia and for which several research studies and pest management programs have been undertaken include the mealybug species Planococcus ficus (Signoret) and Planococcus citri Risso, the soft scale Saissetia oleae (Olivier) and the armoured scale Parlatoria ziziphi (Lucas). The host plants, bio-ecological aspects, auxiliary fauna of each of the aforementioned species as well as the related economic losses and pest management strategies adopted are explored and discussed. Among these species, P. ficus is considered herein as the most economically important in Tunisia. Still, the present contribution constitutes the first review article on key scale insects infesting plants in the South Mediterranean Maghreb area.

scholarly journals Heterologous Movement Protein Strongly Modifies the Infection Phenotype of Cucumber Mosaic Virus

2002 ◽  
Vol 76 (7) ◽  
pp. 3554-3557 ◽  
Author(s):  
Emese Huppert ◽  
Dénes Szilassy ◽  
Katalin Salánki ◽  
Zoltán Divéki ◽  
Ervin Balázs
Keyword(s):  
Nicotiana Tabacum ◽  
Virus Infection ◽  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Host Plants ◽  
Movement Protein ◽  
Long Distance ◽  
Cucumber Mosaic Cucumovirus ◽  
Nicotiana Debneyi ◽  
Symptom Phenotype

ABSTRACT A hybrid virus (CMVcymMP) constructed by replacing the movement protein (MP) of cucumber mosaic cucumovirus (CMV) with that of cymbidium ringspot tombusvirus (CymRSV) was viable and could efficiently spread both cell to cell and long distance in host plants. The hybrid virus was able to move cell to cell in the absence of functional CP, whereas CP-deficient CMV was restricted to single inoculated cells. In several Chenopodium and Nicotiana species, the symptom phenotype of the hybrid virus infection was clearly determined by the foreign MP gene. In Nicotiana debneyi and Nicotiana tabacum cv. Xanthi, the hybrid virus could move systemically, contrary to CymRSV.

scholarly journals The Cpc1 Regulator of the Cross-Pathway Control of Amino Acid Biosynthesis Is Required for Pathogenicity of the Vascular Pathogen Verticillium longisporum

2013 ◽  
Vol 26 (11) ◽  
pp. 1312-1324 ◽  
Author(s):  
Christian Timpner ◽  
Susanna A. Braus-Stromeyer ◽  
Van Tuan Tran ◽  
Gerhard H. Braus
Keyword(s):  
Amino Acid ◽  
Oilseed Rape ◽  
Host Plants ◽  
Pathogenic Fungus ◽  
Amino Acid Biosynthesis ◽  
Amino Acid Starvation ◽  
Acid Biosynthesis ◽  
Plant Host ◽  
Verticillium Longisporum ◽  
The Cross

The plant-pathogenic fungus Verticillium longisporum is a causal agent of early senescence and ripening in cruciferous crops like Brassica napus. Verticillium wilts have become serious agricultural threats in recent decades. Verticillium species infect host plants through the roots and colonize xylem vessels of the host plant. The xylem fluid provides an environment with limited carbon sources and unbalanced amino acid supply, which requires V. longisporum to induce the cross-pathway control of amino acid biosynthesis. RNA-mediated gene silencing reduced the expression of the two CPC1 isogenes (VlCPC1-1 and VlCPC1-2) of the allodiploid V. longisporum up to 85%. VlCPC1 encodes the conserved transcription factor of the cross-pathway control. The silenced mutants were highly sensitive to amino-acid starvation, and the infected plants showed significantly fewer symptoms such as stunting or early senescence in oilseed rape plant infection assays. Consistently, deletion of single CPC1 of the haploid V. dahliae resulted in strains that are sensitive to amino-acid starvation and cause strongly reduced symptoms in the plant-host tomato (Solanum lycopersicum). The allodiploid V. longisporum and the haploid V. dahliae are the first phytopathogenic fungi that were shown to require CPC1 for infection and colonization of their respective host plants, oilseed rape and tomato.

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