scholarly journals First Report of Chestnut Blight Caused by Cryphonectria parasitica in a Chestnut Orchard in Andalusia (Southern Spain)

Plant Disease ◽  
2014 ◽  
Vol 98 (2) ◽  
pp. 283-283 ◽  
Author(s):  
J. Bascón ◽  
S. Castillo ◽  
C. Borrero ◽  
S. Orta ◽  
A. Gata ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Castanea Sativa ◽  
Cryphonectria Parasitica ◽  
Southern Spain ◽  
Chestnut Blight ◽  
Commonwealth Mycological Institute ◽  
Species Identity ◽  
First Report ◽  
Sweet Chestnut ◽  
Agar Plug

In Europe, chestnut blight caused by Cryphonectria parasitica (Murrill) Barr was first seen in Italy in 1938 (1). In Spain, the disease was first detected in Basque country in 1947 and later in other areas of northern Spain: Galicia, León, Navarra, and Catalonia, and in Trás-os-Montes in Portugal (2). In November 2012, in an orchard (2 ha) in Almonaster la Real (Huelva, Spain), approximately 20 cankered Castanea sativa (sweet chestnut) trees cv. Vazqueño, 40 to 50 years old, were observed. The trees were grafted 2 years before. In May and June 2013, six new disease focuses were detected near the first one. Five focuses were located in the same village and the other in Jabugo (a neighboring village). Diseased trees exhibited sunken cankers, cracked bark with mycelial fan spreads under the bark, and in some cases, orange fungal sporulation was visible on the bark. Samples were collected from two affected trees and symptom-bearing bark pieces were then placed in moist chambers at 20°C for up to 8 days to induce fungal sporulation. Cultures were made from spore masses extruding from the cankered bark and from the edge of necrotic lesions visible in the phloem of cankered bark tissue onto potato dextrose agar (PDA). Monoconidial fungal isolates were obtained from both trees. The morphological structure of two isolated fungi was identical to that described as C. parasitica (3). Species identity was confirmed by analysis of nucleotide sequences of the internal transcribed spacer (ITS) rDNA, using ITS1-ITS4 (4) as primer pairs, respectively. BLAST searches showed a high similarity between collected isolates' DNA sequences and C. parasitica sequences found on GenBank (96% coverage, 99% identity). Our isolates have been included in GenBank as KF220298 and KF220299. The pathogenicity assay of these two isolates was conducted using two cultivars of sweet chestnut (seedlings from Huelva and Granada nurseries). Isolate pathogenicity was tested on 3-year-old chestnut seedlings in a growth chamber at 25°C (day) and 20°C (night) with a 14-h photoperiod. The isolates were cultured on PDA at 25°C for 7 days. Stems were wounded at 10 cm height with a drill. Each isolate was inoculated to 25 replicates per cultivar by placing a mycelia agar plug (4 to 5 mm diameter) in the hole and wrapping the stem with Parafilm. Plants treated identically with sterile agar plugs were used as controls. Plants were then maintained at 100% relative humidity for 2 h. Both isolates induced diseases symptoms and death of seedlings of both cultivars at a mean time of 37.5 days after inoculation. No significant differences between isolates or between cultivars were detected. Twenty control plants similarly treated with sterile PDA discs did not display symptoms. C. parasitica was re-isolated from lesions, confirming Koch's postulates. Andalusia has 14,000 ha of chestnut crops with high commercial value due to their precocity. Dispersion of chestnut blight in this zone can reduce crop productivity. To our knowledge, this is the first report of C. parasitica causing chestnut blight in Andalusia (southern Spain), one of the few areas left in southwestern Europe free of chestnut blight. References: (1) A. Biraghi. Italia Agricola 7:1, 1946. (2) G. González-Varela et al. Eur. J. Plant Pathol. 131:67, 2011. (3) A. Sivanesan and P. Holliday. Cryphonectria parasitica. CMI Descriptions of Pathogenic Fungi and Bacteria. No. 704, Set. 71. Commonwealth Mycological Institute, Kew, UK, 1981. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Amplifications. M. A. Innis et al., eds. Academic Press, San Diego, CA, 1990.

scholarly journals Changes in Cryphonectria parasitica Populations Affect Natural Biological Control of Chestnut Blight

2018 ◽  
Vol 108 (7) ◽  
pp. 870-877 ◽  
Author(s):  
Marin Ježić ◽  
Jelena Mlinarec ◽  
Rosemary Vuković ◽  
Zorana Katanić ◽  
Ljiljana Krstin ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Infected Plant ◽  
Castanea Sativa ◽  
Cryphonectria Parasitica ◽  
Chestnut Blight ◽  
Native Plant ◽  
Native Plant Species ◽  
Sweet Chestnut ◽  
Tripartite Interactions ◽  
Disease Management Strategy

Invasive species, especially plant pathogens, have a potential to completely eradicate native plant species and remodel landscapes. Tripartite interactions among sweet chestnut (Castanea sativa), chestnut blight-causing invasive fungus Cryphonectria parasitica, and hyperparasitic virus Cryphonectria hypovirus 1 (CHV1) were studied in two populations. The number of different vegetative compatibility (vc) types of C. parasitica more than doubled over the 10 years, while the hypovirulence incidence dropped in one population and slightly increased in the other one. Over the course of our 3-year monitoring experiment, the prevalence of hypovirulent isolates obtained from monitored cankers increased slowly (i.e., more hypovirulent isolates were being obtained from the same cankers over time). Within studied cankers, considerable changes in vc type and CHV1 presence were observed, indicating a highly dynamic system in which virulent and hypovirulent mycelia, sometimes of discordant vc types, often appeared together. The increase in hypovirulence prevalence did not have any observable curative effect on the cankers and, occasionally, reactivation of healed cankers by new, virulent C. parasitica isolates was observed. Both short- and long-term observations and revalidation of the infected plant populations are necessary to accurately estimate disease progress and formulate an adequate disease management strategy.

scholarly journals New finds of Cryphonectria parasitica and the first record of chestnut blight on red oak Quercus rubra L. in the Czech Republic

2012 ◽  
Vol 51 (No. 6) ◽  
pp. 256-258 ◽  
Author(s):  
P. Haltofová ◽  
L. Jankovský ◽  
D. Palovčíková
Keyword(s):  
Czech Republic ◽  
Castanea Sativa ◽  
First Record ◽  
Cryphonectria Parasitica ◽  
Chestnut Blight ◽  
Red Oak ◽  
The Czech Republic ◽  
Sweet Chestnut ◽  
New Localities ◽  
Endothia Parasitica

The causal agent of the chestnut blight, the fungus Cryphonectria parasitica (Murrill) M. E. Barr (syn. Endothia parasitica (Murrill) P. J. Anderson et H. W. Anderson), was found out at new localities in the Czech Republic. The chestnut blight was observed for the first time in the Czech Republic in 2002. Two new localities were discovered in southern Moravia in May and June 2004. The disease was identified both on the sweet chestnut (Castanea sativa Mill.) and on the red oak (Quercus rubraL.). Infected trees were treated according to the order of the State Phytosanitary Administration of the Czech Republic. 

scholarly journals Management of Chestnut Blight in Greece Using Hypovirulence and Silvicultural Interventions

Forests ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 492 ◽  
Author(s):  
Stephanos Diamandis
Keyword(s):  
Biological Control ◽  
Castanea Sativa ◽  
Pilot Project ◽  
Cryphonectria Parasitica ◽  
Chestnut Blight ◽  
Sweet Chestnut ◽  
Central Greece ◽  
Clear Cutting ◽  
Castanea Sativa Mill ◽  
Nut Production

Sweet chestnut (Castanea sativa Mill.) is an important tree for Greece. The invasive fungus Cryphonectria parasitica, which causes chestnut blight, was first found in Central Greece in 1963. It has since spread all over the country, significantly reducing the national annual nut production. The increasing decline of forests and orchards due to the disease led to a project in 1995, which aimed at studying the feasibility of applying biological control. A prerequisite study of the existing vegetative compatibility types of the pathogen showed only four, and their distribution was mapped. A pilot project (1998–2000) that consisted of clear cutting heavily infected coppice stands and introducing hypovirulence to the remainder was implemented on Mt. Athos on a 7000 ha sweet chestnut forest. Two evaluations (in 2003 and 2011) revealed that hypovirulence was established in the sweet chestnut forests and spread more or less homogeneously. A nationwide project introducing hypovirulence to 29 counties was implemented in two, 3-yr-periods 2007–2009 (17 counties) and 2014–2016 (12 counties). The new evaluations showed that hypovirulence spread profoundly and forests and orchards started recovering. The appearance of natural hypovirulence cannot be predicted. Introduced hypovirulence and silvicultural interventions can be used to manage the disease. It is the responsibility of the forest/orchard manager to decide whether to wait for appearance of natural hypovirulence, or to introduce it for a faster decline in disease.

scholarly journals First Report of Phytophthora pseudosyringae on Chestnut Nursery Stock in Spain

Plant Disease ◽  
2007 ◽  
Vol 91 (11) ◽  
pp. 1517-1517 ◽  
Author(s):  
C. Pintos Varela ◽  
J. P. Mansilla Vázquez ◽  
O. Aguín Casal ◽  
C. Rial Martínez
Keyword(s):  
Dna Sequences ◽  
Aqueous Suspension ◽  
Castanea Sativa ◽  
Leading Edge ◽  
Growth Patterns ◽  
Deciduous Tree ◽  
First Report ◽  
Agar Plug ◽  
Golden Yellow ◽  
Detached Leaves

Phytophthora pseudosyringae causes stem necrosis and collar rot of deciduous tree species (Quercus spp., Fagus silvatica, and Alnus glutinosa) in several European countries (1,2). In November 2006, we received diseased Castanea sativa seedlings from a nursery in Galicia (northwest Spain). These plants had tongue-shaped necroses of the inner bark and cambium. Reddish, sunken lesions occurred on the surface of the bark, either in the stem base or higher on the stem. Tissue from the leading edge of the lesions was transferred to a selective V8 agar medium (4) and incubated for 7 days at 20°C in the dark. A Phytophthora sp. was isolated, transferred to cornmeal agar (CMA) and V8 agar, and incubated in the dark. Colonies were appressed with stellate to rosaceous growth patterns on CMA and stellate, limited aerial mycelium on V8 agar. Growth on V8 occurred from 2 to 25°C with an optimum at 20°C and a radial growth rate of 4.5 mm per day at 20°C. Chains of inflated spherical to deltoid hyphal swellings with radiating hyphae were abundantly produced in water (2). Chlamydospores were not observed on agar media. The deciduous, sympodial, semipapillate, rarely bipapillate sporangia with pedicels had a length/breadth average ratio of 1.55. Oogonia, antheridia, and oospores were produced within a single culture. Oogonia were spherical and smooth walled, antheridia were predominantly paraginous, but some were amphyginous, and oospores were plerotic that turned golden yellow with age (2). Internal transcribed spacer (ITS)-rDNA and mitochondrial DNA (mtDNA) regions were amplified by nested-PCR and sequenced with DNA extracted from mycelium. The amplicon sizes obtained were similar to those reported for P. pseudosyringae (2,3). DNA sequences showed 99 to 100% homology with those previously identified as P. pseudosyringae and deposited in GenBank. Pathogenicity of the isolate was confirmed by inoculating 10 C. sativa seedlings, as well as three detached leaves from each of another 10 young plants growing in containers. For the seedlings, one shallow cut was made into the bark on the main stem. A colonized agar plug was inserted beneath the flap that was sealed with Parafilm. Unwounded and wounded detached leaves of C. sativa were dipped into a zoospore aqueous suspension (1 × 105 zoospores ml–1) for 10 s., seedlings and leaves were incubated at 20°C and 95% humidity for 60 and 7 days, respectively. After 7 days, foliar lesions that developed exceeded 25 mm, and the pathogen was consistently reisolated. Leaves inoculated with sterile water did not develop symptoms. On inoculated seedlings, the external surface of the bark was reddish and sunken. Stem lesions progressed bidirectionally from the wound. P. pseudosyringae was recovered from inoculated seedlings but not from controls. On the basis of its unique combination of morphological and physiological characters, pathogenicity, and ITS and mtDNA sequences, the Phytophthora isolated from chestnut was identified as P. pseudosyringae. To our knowledge, this is the first report of P. pseudosyringae on C. sativa in Spain. References: (1) EPPO Reporting Service. Online publication. No. 10 2005/162, 2005. (2) T. Jung et al. Mycol. Res. 107:772, 2003. (3) F. N. Martin et al. Phytopathology 94:621, 2004. (4) C. Pintos Varela et al. Plant. Dis. 87:1396, 2003.

scholarly journals Die Edelkastanien (Castanea sativa) am Südhang des Urmiberges, Kanton Schwyz | Sweet chestnut (Castanea sativa) on the southern slopes of Urmiberg, canton of Schwyz

2002 ◽  
Vol 153 (12) ◽  
pp. 476-478
Author(s):  
Ursula Heiniger ◽  
Andreas Schilter ◽  
Roger Wirz
Keyword(s):  
Castanea Sativa ◽  
Cryphonectria Parasitica ◽  
Wide Distribution ◽  
Economic Importance ◽  
Fruit Tree ◽  
Chestnut Blight ◽  
The West ◽  
Sweet Chestnut ◽  
Central Switzerland ◽  
Open Land

Around 1900, the sweet chestnut (Castanea sativa) was widespread near the lakes of Central Switzerland. It was mainly cultivated as a fruit tree. Today the tree has lost its economic importance,but it is still a beautiful landscape element. ENGLER (1900) found a wide distribution of the sweet chestnut on the south-western slopes of the Urmiberg. These chestnuts had largely disappeared by 1958 (FURRER 1958). In 1999 the occurrence of the sweet chestnut was mapped on the Urmiberg and compared with maps made by ENGLER (1900) and FURRER(1958). The results show that the sweet chestnut has disappeared from the open land on the Urmiberg with the exception of one tree at Hebleren. Today several tree groups are to be found to the west of the study area at the edge of the forest and in the forest along the Bärenfallenweg and near Schroten-Dörfli. Only two trees were found with a dbh > 1 m;the majority had dbhs between 10 and 40 cm. All the trees were healthy and showed no signs of chestnut blight (Cryphonectria parasitica). For the future preservation of the sweet chestnut, special care and management needs to be applied.

scholarly journals The role of production site isolation in the plant health situation of sweet chestnut (Castanea sativa)

2017 ◽  
pp. 79-82
Author(s):  
Gabriella Kovács ◽  
László Radócz
Keyword(s):  
Castanea Sativa ◽  
Cryphonectria Parasitica ◽  
Western Slope ◽  
Past Century ◽  
Sweet Chestnut ◽  
European Chestnut ◽  
Disease Occurrence ◽  
New Perspective ◽  
Blight Disease ◽  
Health Situation

The most destructive pathogen for the European chestnut is the blight fungus Cryphonectria parasitica (Murr.) Barr. The spread of the fungus was very fast in Europe within a few decades in the second half of the past century. During the tree-health checking in the chestnut andwalnut plantation in Romania, Hargita county, next to Homoródkarácsonyfalva village, we especially concentraded on the signs of blight disease occurrence. The grove is laying on a western slope, under a pine forest. This favourable geographical space protects it not only from pathogen attacts, but it has a special, mild microclimate for nut and chestnut trees. The European chestnut could be a valuable member of local forests, opening a new perspective under conditions of climate changes.

scholarly journals The Morphology and the Biological Control of Cryphonectria parasitica

2012 ◽  
Vol 69 (1) ◽  
Author(s):  
Carmen Emilia PUIA ◽  
Daniela Andreea GRIGORESCU ◽  
Raluca Vasilica MICLEA
Keyword(s):  
Biological Control ◽  
Virulent Strain ◽  
Morphological Characteristics ◽  
Castanea Sativa ◽  
Cryphonectria Parasitica ◽  
Chestnut Blight ◽  
Dual Culture ◽  
Natural Form ◽  
Hypovirulent Strain ◽  
Endothia Parasitica

Cryphonectria parasitica  (Murr.) Bar [syn. Endothia parasitica (Murr. And.] (anamorf: Endothiella sp .) is the causal agent of chestnut bark disease or chestnut blight, disease which produced great damages throughout the world, for example, in Europe, the European chestnut tree ( Castanea sativa (P.) Mill) was heavily affected. Environmental concerns have focused attention on natural forms of disease control as an effective alternative to chemical pesticides. In the chestnut blight fungus, Cryphonectria parasitica deals with a natural form of biological control in which the virulence of a fungal pathogen is attenuated by an endogenous viral RNA genetic element- the hypovirulent strain. In our researches we picked samples of chestnut bark from different areas in Maramures county. We’ve isolated the fungus on PDA medium and we’ve studied the morphological characteristics of the usual virulent strain and we looked for a possible hypovirulent strain in order to study its capacity for biological control. The fungus develops in the bark and in cambium where forms a yellowish or brownish stroma and produces both conidia and ascospores. The pycnidia stromata break through the lenticels producing conidia and later in the same stroma develop the perithecia which produce ascospores. Both strains of the fungus were found in the research area. The hypovirulent strain had a slower development, showed no sporu lation and pigmentation “white cultural strain” and was tested in vitro for the capacity to convert the virulent isolates by dual culture tests.

scholarly journals Studies of Cryphonectria parasitica (MURR.) BARR subpopulations on Quercus petraea in Ukraine

2011 ◽  
pp. 70-75
Author(s):  
László Radócz ◽  
Gábor Tarcali ◽  
László Irinyi ◽  
Gábor Görcsös
Keyword(s):  
Fungal Pathogens ◽  
Castanea Sativa ◽  
Cryphonectria Parasitica ◽  
Quercus Petraea ◽  
Carpathian Basin ◽  
Chestnut Blight ◽  
Oak Trees ◽  
Compatibility Group ◽  
Laboratory Examinations ◽  
Blight Disease

Chryphonectria parasitica (Murr.) Barr, the casual agent of chestnut blight disease, which is one of the most important fungal pathogens of chestnut (Castanea sativa). The disease seriously affected the chestnut in Northern-America and in Europe as well. It is important to mention that the pathogen does not only infect the chestnut but oak species (Quercus spp.) also. In the Carpathian-Basin, the chestnut is endemic in the Mecsek mountains, in Zala, in Somogy counties but it also can be found in the Danube-Bend. In the Carpathian-Basin (outside Hungary) the chestnut is found in Slovakia, Ukraine, Romania. In our study bark samples infected by Cryphonectria parasitica were collected from Bobovyshche, Serednje and Rostovjatica (Ukraine). The rate of infected chestnut tree were higher than 90% around Bobovyshche and beside chestnut, the symptoms were detected on oak trees as well. We collected bark samples from chestnut and oak as well and then we isolated the pathogen Cryphonectria parasitica in the lab of University of Debrecen. Symptomatological observations, laboratory examinations on fungus morphology, as well as comparisons of ITS sequency homology were made and approved that the causal agent of new disease was Cryphonectria parasitica. Our results proved that the Cryphonectria. parasitica infects oak trees beside chestnut in the Carpathian-Basin. Further studies are needed to determine the VCG (Vegatative Compatibility Group) group of the Cryphonectria parasitica found on oak trees. 

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