No Indication of Strict Host Associations in a Widespread Mycoparasite: Grapevine Powdery Mildew (Erysiphe necator) Is Attacked by Phylogenetically Distant Ampelomyces Strains in the Field

Pycnidial fungi belonging to the genus Ampelomyces are common intracellular mycoparasites of powdery mildews worldwide. Some strains have already been developed as commercial biocontrol agents (BCAs) of Erysiphe necator and other powdery mildew species infecting important crops. One of the basic, and still debated, questions concerning the tritrophic relationships between host plants, powdery mildew fungi, and Ampelomyces mycoparasites is whether Ampelomyces strains isolated from certain species of the Erysiphales are narrowly specialized to their original mycohosts or are generalist mycoparasites of many powdery mildew fungi. This is also important for the use of Ampelomyces strains as BCAs. To understand this relationship, the nuclear ribosomal DNA internal transcribed spacer (ITS) and partial actin gene (act1) sequences of 55 Ampelomyces strains from E. necator were analyzed together with those of 47 strains isolated from other powdery mildew species. These phylogenetic analyses distinguished five major clades and strains from E. necator that were present in all but one clade. This work was supplemented with the selection of nine inter-simple sequence repeat (ISSR) markers for strain-specific identification of Ampelomyces mycoparasites to monitor the environmental fate of strains applied as BCAs. The genetic distances among strains calculated based on ISSR patterns have also highlighted the genetic diversity of Ampelomyces mycoparasites naturally occurring in grapevine powdery mildew. Overall, this work showed that Ampelomyces strains isolated from E. necator are genetically diverse and there is no indication of strict mycohost associations in these strains. However, these results cannot rule out a certain degree of quantitative association between at least some of the Ampelomyces lineages identified in this work and their original mycohosts.

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Genetic Structure and Aggressiveness of Erysiphe necator Populations during Grapevine Powdery Mildew Epidemics

Applied and Environmental Microbiology ◽

10.1128/aem.01200-08 ◽

2008 ◽

Vol 74 (20) ◽

pp. 6327-6332 ◽

Cited By ~ 30

Author(s):

Josselin Montarry ◽

Philippe Cartolaro ◽

François Delmotte ◽

Jérôme Jolivet ◽

Laetitia Willocquet

Keyword(s):

Powdery Mildew ◽

Latency Period ◽

Growing Season ◽

Spore Production ◽

Erysiphe Necator ◽

Genetic Groups ◽

Grapevine Powdery Mildew ◽

Temporal Differentiation ◽

Group A ◽

Group B

ABSTRACT Isolates of the causal ascomycete of grapevine powdery mildew, Erysiphe necator, correspond to two genetically differentiated groups (A and B) that coexist on the same host. This coexistence was analyzed by investigating temporal changes in the genetic and phenotypic structures of E. necator populations during three epidemics. Group A was present only at the start of the growing season, whereas group B was present throughout all three epidemics. Group A was less aggressive in terms of germination and infection efficiency but was more aggressive than group B in terms of the latency period, lesion diameter, and spore production. Our results are consistent with a temporal differentiation of niches, preventing recombination, and suggest an association between the disease level and the frequencies of genetic groups.

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Taxonomic revision and phylogenetic analyses of rubber powdery mildew fungi

Microbial Pathogenesis ◽

10.1016/j.micpath.2017.01.054 ◽

2017 ◽

Vol 105 ◽

pp. 185-195 ◽

Cited By ~ 8

Author(s):

K.K. Liyanage ◽

Sehroon Khan ◽

Siraprapa Brooks ◽

Peter E. Mortimer ◽

Samantha C. Karunarathna ◽

...

Keyword(s):

Powdery Mildew ◽

Phylogenetic Analyses ◽

Taxonomic Revision ◽

Powdery Mildew Fungi

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Using a limited mapping strategy to identify major QTLs for resistance to grapevine powdery mildew (Erysiphe necator) and their use in marker-assisted breeding

Theoretical and Applied Genetics ◽

10.1007/s00122-010-1511-6 ◽

2010 ◽

Vol 122 (6) ◽

pp. 1059-1073 ◽

Cited By ~ 71

Author(s):

S. Riaz ◽

A. C. Tenscher ◽

D. W. Ramming ◽

M. A. Walker

Keyword(s):

Powdery Mildew ◽

Marker Assisted Breeding ◽

Erysiphe Necator ◽

Major Qtls ◽

Mapping Strategy ◽

Grapevine Powdery Mildew

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Reprint of “Sequence and phylogenetic analyses of novel totivirus-like double-stranded RNAs from field-collected powdery mildew fungi”

Virus Research ◽

10.1016/j.virusres.2016.05.011 ◽

2016 ◽

Vol 219 ◽

pp. 39-50 ◽

Cited By ~ 1

Author(s):

Hideki Kondo ◽

Sakae Hisano ◽

Sotaro Chiba ◽

Kazuyuki Maruyama ◽

Ida Bagus Andika ◽

...

Keyword(s):

Powdery Mildew ◽

Phylogenetic Analyses ◽

Powdery Mildew Fungi

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Molecular phylogenetic analyses reveal a close relationship between powdery mildew fungi on some tropical trees and Erysiphe alphitoides, an oak powdery mildew

Mycoscience ◽

10.1007/s10267-006-0311-y ◽

2006 ◽

Vol 47 (6) ◽

pp. 327-335 ◽

Cited By ~ 39

Author(s):

Saranya Limkaisang ◽

Susumu Takamatsu ◽

James Henry Cunnington ◽

Liew Kon Wui ◽

Baharuddin Salleh ◽

...

Keyword(s):

Powdery Mildew ◽

Phylogenetic Analyses ◽

Tropical Trees ◽

Erysiphe Alphitoides ◽

Close Relationship ◽

Molecular Phylogenetic ◽

Powdery Mildew Fungi

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Overwintering form of Erysiphe necator, the causal agent of grapevine powdery mildew in southern Syria

Journal of Plant Protection Research ◽

10.1515/jppr-2017-0017 ◽

2017 ◽

Vol 57 (2) ◽

pp. 129-135 ◽

Cited By ~ 1

Author(s):

Nujoud Alimad ◽

Walid Naffaa ◽

Fawaz Azmeh

Keyword(s):

Powdery Mildew ◽

Winter Season ◽

Causal Agent ◽

Bud Break ◽

Erysiphe Necator ◽

First Report ◽

Primary Inoculum ◽

Grapevine Powdery Mildew ◽

Histopathological Studies ◽

Grapevine Buds

AbstractThe main aims of this study were to determine the overwintering form and the primary inoculum ofErysiphe necator,the causal agent of grapevine powdery mildew in southern Syria. Eleven vineyards located at five different geographical sites were visited every week from March to November in 2014 and 2015. The results of field and histopathological studies showed thatE. necatorsurvived as mycelium in dormant grapevine buds during the winter season. The first flag shoots were observed shortly after bud break in spring. The number of flag shoots varied greatly according to vineyards, cultivars and years, being present on 27.4 to 61.9% of the grapevines in 2014, and on 5.2 to 40% of the grapevines in 2015. The percentage of flag shoots on the same grapevine also varied according to the year, cultivar and location. It was between 4.3 to 9.4% in 2014, and 2.1 to 3.6% in 2015. The disease was observed only on Balady and Black cultivars. Conidia were released from the second week of May to early September. The first conidia were trapped around mid-May, and the first secondary symptoms were observed on leaves from mid-May to early June according to the site. Chasmothecia were observed on leaves in 45.5% of the studied vineyards. The first observation of chasmothecia on leaves was in July, and their numbers varied greatly between vineyards and years. Chasmothecia were not detected on bark, nor were ascospores trapped at the beginning of the season. These results confirmed that the ascospores did not have any role in the initiation of spring infection. To the best of our knowledge, this is the first report of the overwintering form ofE. necatorin Syria.

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Infection of papaya (Carica papaya) by four powdery mildew fungi

Phytopathologia Mediterranea ◽

10.36253/phyto-11976 ◽

2021 ◽

Vol 60 (1) ◽

pp. 37-49

Author(s):

Diána SERESS ◽

Gábor M. KOVÁCS ◽

Orsolya MOLNÁR ◽

Márk Z. NÉMETH

Keyword(s):

Powdery Mildew ◽

New Record ◽

Species Complex ◽

Carica Papaya ◽

Phylogenetic Analyses ◽

Molecular Taxonomy ◽

Podosphaera Xanthii ◽

Powdery Mildew Fungus ◽

Molecular Phylogenetic ◽

Powdery Mildew Fungi

Papaya (Carica papaya L.) is an important fruit crop in many tropical and subtropical countries. Powdery mildew commonly affects this host, causing premature leaf loss, reduced yields and poor fruit quality. At least fifteen different fungi have been identified as the causal agents of papaya powdery mildew. Powdery mildew symptoms were detected on potted papaya plants growing in two locations in Hungary. This study aimed to identify the causal agents. Morphology of powdery mildew samples was examined, and sequences of two loci were used for molecular taxonomic identifications. Only anamophs were detected in all samples, and four morphological types were distinguished. Most samples had Pseudoidium anamorphs, while some were of the Fibroidium anamorph. Based on morphology and molecular taxonomy, the Fibroidium anamorph was identified as Podosphaera xanthii. The Pseudoidium anamorphs corresponded to three different Erysiphe species: E. cruciferarum, E. necator and an unidentified Erysiphe sp., for which molecular phylogenetic analyses showed it belonged to an unresolved species complex of E. malvae, E. heraclei and E. betae. Infectivity of P. xanthii and E. necator on papaya was verified with cross inoculations. A review of previous records of powdery mildew fungi infecting papaya is also provided. Podosphaera xanthii was known to infect, and E. cruciferarum was suspected to infect Carica papaya, while E. necator was recorded on this host only once previously. No powdery mildew fungus belonging to the E. malvae/E. heraclei/E. betae species complex is known to infect papaya or any other plants in the Caricaceae, so the unidentified Erysiphe sp. is a new record on papaya and the Caricaceae. This study indicates host range expansion of this powdery mildew fungus onto papaya.

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