Occurrence of Pseudonectria foliicola Causing Volutella Blight on Boxwood in Czech Republic

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F62156489%3A43510%2F20%3A43917914" target="_blank" >RIV/62156489:43510/20:43917914 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1094/PDIS-09-19-2046-PDN" target="_blank" >https://doi.org/10.1094/PDIS-09-19-2046-PDN</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1094/PDIS-09-19-2046-PDN" target="_blank" >10.1094/PDIS-09-19-2046-PDN</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Occurrence of Pseudonectria foliicola Causing Volutella Blight on Boxwood in Czech Republic

Popis výsledku v původním jazyce

Pseudonectria foliicola L. Lombard &amp; Crous is a fungal pathogen of boxwood described for the first time by Lombard et al. (2015). Together with the fungus Pseudonectria buxi, this pathogen causes Volutella blight disease of Buxus sempervirens L., an important ornamental shrub (Salgado-Salazar et al. 2019). Symptoms of Volutella blight include leaf discoloration, twig dieback, and in some cases, salmon to pink sporodochia developing on the surface of the leaves and twigs (Rivera et al. 2018). In August 2018, stems of six symptomatic plants (bronze leaves, dead twigs, and salmon sporodochia on the bottom surface of the leaves) were sampled from boxwood in three city parks in the Znojmo region, Czech Republic. The disease incidence was approximately 10% of the boxwood plants through the city parks. Pieces of wood, 5 mm in diameter without bark, were surface sterilized for 1 min using 1% solution of sodium hypochlorite, rinsed three times with sterilized water, and placed onto the surface of potato dextrose agar plates. These were incubated at 25oC in the dark for 1 week. Mycelium emerging from the pieces of wood was fluffy and white with scattered salmon/pink masses of conidia forming from sporodochia at the colony margins after 10 days. Three isolates were obtained, one from each location. Length and width of 30 conidia per isolate were measured. Conidia (n = 30) were hyaline, aseptate, and fusiform to ellipsoidal, measuring 4.52 +- 0.86 x 2.93 +- 0.42 μm. One representative isolate was selected, and its identity was confirmed by sequencing the internal transcribed spacer of ribosomal DNA (ITS) and the β-tubulin (Tub) gene using primers ITS1/ITS4 and T1/BTb2, respectively (Glass and Donaldson 1995; O&apos;Donnell and Cigelnik 1997; White et al. 1990). The sequences were 100% identical (ITS 559/559 nt, Tub 511/511 nt) with the P. foliicola ex-type (CBS 123190) sequences KM231776.1 and KM232035.1. The sequences were deposited in GenBank/NCBI under MN091009 and MN091010, respectively. The strain was deposited in the Mycological Collection of Mendeleum, Mendel University in Brno, Czech Republic, under accession number MEND-F-0129. Ten plants of 3-year-old B. sempervirens grown in pots were used to confirm the pathogenicity of this species. Five plants were inoculated with one isolate of the pathogen, and five plants were used as controls. The trial was repeated twice. The plants were wounded with a sterile 5-mm cork borer, and a 5-mm mycelial plug of a 10-day-old culture was inserted into the wound. Wounds were sealed with Parafilm and aluminum foil. Plants were maintained under field conditions for 3 months (June to August) after inoculation. Necrotic stem lesions appeared after 3 months, but not on control plants. The fungus was successfully reisolated from the symptomatic wood tissues of the infected plants but not from the controls. P. foliicola has already been reported from New Zealand and the United States (Farr and Rossman 2019). To our knowledge, this is the first report of isolation and pathogenicity testing of P. foliicola in the Czech Republic and Europe. This disease could cause serious economic losses, especially to nurseries producing boxwood plants in the Czech Republic.

Název v anglickém jazyce

Occurrence of Pseudonectria foliicola Causing Volutella Blight on Boxwood in Czech Republic

Popis výsledku anglicky

Pseudonectria foliicola L. Lombard &amp; Crous is a fungal pathogen of boxwood described for the first time by Lombard et al. (2015). Together with the fungus Pseudonectria buxi, this pathogen causes Volutella blight disease of Buxus sempervirens L., an important ornamental shrub (Salgado-Salazar et al. 2019). Symptoms of Volutella blight include leaf discoloration, twig dieback, and in some cases, salmon to pink sporodochia developing on the surface of the leaves and twigs (Rivera et al. 2018). In August 2018, stems of six symptomatic plants (bronze leaves, dead twigs, and salmon sporodochia on the bottom surface of the leaves) were sampled from boxwood in three city parks in the Znojmo region, Czech Republic. The disease incidence was approximately 10% of the boxwood plants through the city parks. Pieces of wood, 5 mm in diameter without bark, were surface sterilized for 1 min using 1% solution of sodium hypochlorite, rinsed three times with sterilized water, and placed onto the surface of potato dextrose agar plates. These were incubated at 25oC in the dark for 1 week. Mycelium emerging from the pieces of wood was fluffy and white with scattered salmon/pink masses of conidia forming from sporodochia at the colony margins after 10 days. Three isolates were obtained, one from each location. Length and width of 30 conidia per isolate were measured. Conidia (n = 30) were hyaline, aseptate, and fusiform to ellipsoidal, measuring 4.52 +- 0.86 x 2.93 +- 0.42 μm. One representative isolate was selected, and its identity was confirmed by sequencing the internal transcribed spacer of ribosomal DNA (ITS) and the β-tubulin (Tub) gene using primers ITS1/ITS4 and T1/BTb2, respectively (Glass and Donaldson 1995; O&apos;Donnell and Cigelnik 1997; White et al. 1990). The sequences were 100% identical (ITS 559/559 nt, Tub 511/511 nt) with the P. foliicola ex-type (CBS 123190) sequences KM231776.1 and KM232035.1. The sequences were deposited in GenBank/NCBI under MN091009 and MN091010, respectively. The strain was deposited in the Mycological Collection of Mendeleum, Mendel University in Brno, Czech Republic, under accession number MEND-F-0129. Ten plants of 3-year-old B. sempervirens grown in pots were used to confirm the pathogenicity of this species. Five plants were inoculated with one isolate of the pathogen, and five plants were used as controls. The trial was repeated twice. The plants were wounded with a sterile 5-mm cork borer, and a 5-mm mycelial plug of a 10-day-old culture was inserted into the wound. Wounds were sealed with Parafilm and aluminum foil. Plants were maintained under field conditions for 3 months (June to August) after inoculation. Necrotic stem lesions appeared after 3 months, but not on control plants. The fungus was successfully reisolated from the symptomatic wood tissues of the infected plants but not from the controls. P. foliicola has already been reported from New Zealand and the United States (Farr and Rossman 2019). To our knowledge, this is the first report of isolation and pathogenicity testing of P. foliicola in the Czech Republic and Europe. This disease could cause serious economic losses, especially to nurseries producing boxwood plants in the Czech Republic.

Druh

O - Ostatní výsledky

CEP obor

—

OECD FORD obor

10611 - Plant sciences, botany

Projekt

<a href="/cs/project/EF16_017%2F0002334" target="_blank" >EF16_017/0002334: Výzkumná infrastruktura pro mladé vědce</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů