First Report of Diaporthe ambigua associated with dead arm disease on grapevine in Chile

Grapevine (Vitis vinifera L.) is one of the most important fruit crops in Chile based on economic value. Phaeomoniella chlamydospora and Botryosphaeriaceae species have been reported as the major causal agents associated with dieback symptoms in Chile commercial vineyards (Díaz and Latorre 2014; Besoain, 2018; Larach et al. 2020). Recently Eutypa lata has been reported attacking Chilean vineyards with dieback symptoms (Lolas et al. 2020). In this study, two commercial cv. Cabernet Sauvignon vineyards, located in O'Higgins Region of Chile, showing dead cordons, dead spur with a grayish color, canker, and vascular necrosis were sampled in fall 2018, with a high incidence of symptoms was observed. Four symptomatic wood samples were analyzed from these vineyards. Pieces of wood (<1 cm2) were taken from the advance zone of the canker lesions, disinfected with 70% ethanol, rinsed in sterile distilled water, dried, and transferred to two media in Petri plates, potato dextrose agar acidified with 0.5 ml of 96% lactic acid (APDA) and malt extract agar, and incubated for at least seven days at 24°C in darkness. From mycelium obtained from monosporic culture, two isolates were selected and morphologically identified as Diaporthe sp. To induce sporulation, these two isolates were grown in APDA under near-ultraviolet light (λ = 320 nm) at room temperature. After 30 days, the development of pycnidia was observed. Both Diaporthe sp. isolate presented alpha-conidia ellipsoidal with an obtuse apex, biguttulate (n=30) of 6.7 µm ± 0.33 µm x 3.3 µm ± 0.32 µm. No Beta-conidia or perhitecia were observed. DNA was extracted from the monosporic mycelium. The ribosomal internal transcribed spacer (ITS), β-tubulin (BT) gene, and elongation factor (EF) gene were amplified using ITS4/ITS5, Bt2a/Bt2b, and EF1-728F/EF1-986R primer pairs, respectively. PCR products were sequenced and identified as Diaporthe ambigua Nitschke (PUCV2140 and PUCV2141), showing 100% sequence identity with ITS MH864620.1, 99.8% with BT MG281142.1, and 100% with EF KC343738.1 sequences from D. ambigua. Sequences were deposited in GenBank (ITS: accession numbers MW301136, MW301137; BT: MW323445, MW323446 and EF: MW308305, MW308306). Two pathogenicity tests were performed with strains PUCV2140 and PUCV2141 using 2-year-old V.vinifera cv. Cabernet Sauvignon. In each test, three plants were used per isolate, considering one plant as an experimental unit. In the first test, a 5 mm mycelial plug from a 6-day-old APDA culture was inoculated using an oblique cut made in the bark with a sterile scalpel and done at the middle of the trunk. In the second test, the trial was done under the same described conditions previously, but in this case, one-year-old semi-lignified shoots were inoculated between two internodes, using mycelial plugs, one shoot for each plant. Injured plants but treated with sterile APDA plugs were used as controls. Plants were placed in natural conditions, and after three months from inoculations, plants showed a cortical canker and brown vascular lesions. Non-inoculated plants remained asymptomatic. The lengths of the cankers were 22.0 ± 1.8 mm and 10.5 ± 0.6 mm, after inoculations of the trunk and cane, respectively. The vascular lesions were 37.0 ± 3.3 and 18.0 ± 2.0 mm, in trunk and cane inoculations, respectively. D. ambigua was re-isolated and reidentified morphologically from the inoculated symptomatic plants, confirming Koch’s postulate. Also, the plants inoculated on the trunk showed premature leaf drop. To our knowledge, this is the first report of D. ambigua associated with dieback affecting grapevines in Chile. Previous D. ambigua was reported causing fruit rots (Auger et al. 2013; Díaz et al. 2017) and cordon dieback in kiwifruit (Díaz and Latorre, 2018), and stem canker and dieback in blueberry (Elfar et al. 2013) in Chile. This study reports a new species of fungi for Chile associated with the dead arm in vineyards. D. ambigua is a pathogen in essential crops in our country. Therefore, it is important to study its prevalence in the future.

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First Report of Lasiodiplodia theobromae Associated with Decline of Grapevine Rootstock Mother Plants in Spain

Plant Disease ◽

10.1094/pdis-92-5-0832b ◽

2008 ◽

Vol 92 (5) ◽

pp. 832-832 ◽

Cited By ~ 13

Author(s):

A. Aroca ◽

R. Raposo ◽

D. Gramaje ◽

J. Armengol ◽

S. Martos ◽

...

Keyword(s):

Elongation Factor ◽

Aerial Mycelium ◽

Its Region ◽

Pathogenic Fungi ◽

Vascular Lesions ◽

Malt Extract ◽

Pathogenicity Test ◽

Lasiodiplodia Theobromae ◽

First Report ◽

Mother Plants

A field of Richter 110 rootstock mother plants in Valencia Province (eastern Spain) was surveyed during November 2006 to study the mycoflora of declining plants. Two canes with stunted leaves were collected from a plant with a reduced number of shoots. No cankers or vascular lesions were observed in the collected canes. Six wood chips (1 to 2 mm thick) were taken from one basal fragment (3 to 4 cm long) of each cane, surface sterilized in 70% ethanol for 1 min, and plated on malt extract agar supplemented with 0.5 g L–1 of streptomycin sulfate. Petri dishes were incubated for 7 days at 25°C. A fungus was consistently isolated from all samples that showed the following characteristics: colonies grown on potato dextrose agar (PDA) at 25°C developed a white, aerial mycelium that turned gray after 4 to 6 days and produced pycnidia after 1 month on sterile grapevine slivers of twigs placed on the PDA surface; conidia from culture were ellipsoidal, thick walled, initially hyaline, nonseptate, and measuring 20 to 25 (22.5) × 12 to 14 (13) μm; aged conidia were brown, 1-septate with longitudinal striations in the wall; and pseudoparaphyses variable in form and length were interspersed within the fertile tissue. The fungus was identified as Lasiodiplodia theobromae (Pat.) Griffon & Maubl. from the above characteristics (2). Identity was confirmed by analysis of the nucleotide sequences of the internal transcribed spacer (ITS) region from the rRNA repeat and part of the translation elongation factor 1-alpha (EF1-α) and the β-tubulin (B-tub) genes, as done elsewhere (1,3). BLAST searches at GenBank showed a high identity with reference sequences (ITS: 100%, EF1-α: 97%; B-tub: 99%). Representative sequences of the studied DNA regions were deposited at GenBank (Accession Nos.: ITS: EU254718; EF1-α: EU254719; and B-tub: EU254720). A pathogenicity test was conducted on 1-year-old grapevine plants cv. Macabeo grafted onto Richter 110 rootstocks maintained in a greenhouse. A superficial wound was made on the bark of 10 plants with a sterilized scalpel, ≈10 cm above the graft union. A mycelial plug obtained from the margin of an actively growing fungal colony (isolate JL664) was placed in the wound and the wound was wrapped with Parafilm. Ten additional control plants were inoculated with sterile PDA plugs. All control plants grew normally, and the inoculation wound healed 3 months after inoculation. Plants inoculated with L. theobromae showed no foliar symptoms in the same period, but developed cankers variable in size surrounding the inoculation sites. Vascular necroses measuring 8.4 ± 1.5 cm (mean ± standard error) developed in the inoculated plants that were significantly longer than the controls (0.3 ± 0.2 cm). The pathogen was reisolated from all inoculated plants and no fungus was reisolated from the controls. These results confirmed the pathogenicity of L. theobromae to grapevine and points to a possible involvement of L. theobromae in the aetiology of grapevine decline as previously reported (3,4). To our knowledge, this is the first report of L. theobromae isolated from grapevine in Spain. References: (1) J. Luque et al. Mycologia 97:1111, 2005. (2) E. Punithalingam. No. 519 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1976. (3) J. R. Úrbez-Torres et al. Plant Dis. 90:1490, 2006. (4) J. M. van Niekerk et al. Phytopathol. Mediterr. 45(suppl.):S43, 2006.

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First Report of Phaeoacremonium krajdenii Causing Petri Disease of Grapevine in Spain

Plant Disease ◽

10.1094/pdis-11-10-0808 ◽

2011 ◽

Vol 95 (5) ◽

pp. 615-615 ◽

Cited By ~ 3

Author(s):

D. Gramaje ◽

M. I. Aguilar ◽

J. Armengol

Keyword(s):

Tap Water ◽

Vitis Vinifera L ◽

Sodium Hypochlorite Solution ◽

Malt Extract ◽

First Report ◽

Worldwide Distribution ◽

Black Spots ◽

Pathogenicity Tests ◽

Weak Growth ◽

Human Infections

In September 2009, symptoms of grapevine (Vitis vinifera L.) decline were observed on 3-year-old grapevines in a vineyard in Roquetas de Mar (Almeria Province, southern Spain). Affected vines were weak with reduced foliage and chlorotic leaves. Black spots and dark streaking of the xylem vessels could be seen in cross- or longitudinal sections of the rootstock trunk. Symptomatic plants were collected and sections (10 cm long) were cut from the basal end of the rootstocks, washed under running tap water, surface disinfested for 1 min in a 1.5% sodium hypochlorite solution, and washed twice with sterile distilled water. The sections were split longitudinally and small pieces of discolored tissues were plated onto malt extract agar (MEA) supplemented with 0.5 g liter–1 of streptomycin sulfate. Dishes were incubated at 25 to 26°C in the dark for 14 to 21 days, and all colonies were transferred to potato dextrose agar (PDA). A Phaeoacremonium sp. was consistently isolated from necrotic tissues. Single conidial isolates were obtained and grown on PDA and MEA in the dark at 25°C for 2 to 3 weeks until colonies produced spores (2). Colonies were grayish brown on PDA and dark brown on MEA. Conidiophores were short and unbranched and 11.5 to 46 (25.5) μm long. Phialides were often polyphialidic. Conidia were hyaline, oblong-ellipsoidal or allantoid, 2.5 to 5 (4.2) μm long, and 1 to 1.7 (1.2) μm wide. On the basis of these characters, the isolates were identified as Phaeoacremonium krajdenii L. Mostert, Summerb. & Crous (1,2). DNA sequencing of a fragment of the beta-tubulin gene of the isolate (Pkr-1) using primers T1 and Bt2b (GenBank Accession No. HM637892) matched P. krajdenii GenBank Accession No. AY579330. Pathogenicity tests were conducted using isolate Pkr-1. Ten 1-year-old callused and rooted cuttings of 110 R rootstock grown in pots with sterile peat were wounded at the uppermost internode with an 8-mm cork borer. A 5-mm mycelium PDA plug from a 2-week-old culture was placed in the wound before being wrapped with Parafilm. Ten control plants were inoculated with 5-mm noncolonized PDA plugs. Plants were maintained in a greenhouse at 25 to 30°C. Within 3 months, shoots on all Phaeoacremonium-inoculated cuttings had weak growth with small leaves and short internodes and there were black streaks in the xylem vessels. The vascular necroses that developed on the inoculated plants were 5.5 ± 1.2 cm long, significantly greater than those on the control plants (P < 0.01). Control plants did not show any symptoms. The fungus was reisolated from discolored tissue of all inoculated cuttings, completing Koch's postulates. P. krajdenii has a worldwide distribution, although these reports are from human infections (1). P. krajdenii was first reported as a pathogen of grapevines in South Africa (1). To our knowledge, this is the first report of P. krajdenii causing young grapevine decline in Spain or any country in Europe. References: (1) L. Mostert et al. J. Clin. Microbiol. 43:1752, 2005. (2) L. Mostert et al. Stud. Mycol. 54:1, 2006.

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First Report of Dieback on Euonymus fortunei Caused by Cylindrocladiella parva in Germany

Plant Disease ◽

10.1094/pdis-02-13-0162-pdn ◽

2013 ◽

Vol 97 (8) ◽

pp. 1120-1120 ◽

Cited By ~ 2

Author(s):

U. Brielmaier-Liebetanz ◽

S. Wagner ◽

S. Werres

Keyword(s):

Morphological Characteristics ◽

Day Length ◽

Morphological Identification ◽

Malt Extract ◽

Tubulin Gene ◽

First Report ◽

Near Ultraviolet ◽

Euonymus Fortunei ◽

Negative Controls ◽

Β Tubulin

In August 2011, a severe shoot dieback was observed on several hundred plants of 1-year-old Euonymus fortunei cv. Emerald 'n Gold in a nursery in Lower Saxony and on a cemetery in Berlin. Single shoots or the whole plant were affected. Chocolate brown lesions around the shoots spread primarily acropetally to be followed by wilting of the shoot tip, reddish discoloration, dropping of leaves, and finally plant death. Two fungal isolates, JKI 2187 and JKI 1288, forming white mycelium on 2% malt extract agar (MEA) were obtained from symptomatic shoots. Both were identified by their morphology as Cylindrocladiella parva (P.J. Anderson) Boesewinkel (syn. Cylindrocladium parvum). After incubation for one week at 25°C in the dark, the reverse side of the colony became buff to ochreous and this was associated with development of long chains of chlamydospores. Microsclerotia and fruiting bodies were not observed. Morphological characteristics were determined on synthetic nutrient agar (SNA) after 7 days at 25°C under near-ultraviolet light. The conidiophores were penicillately branched. The stipe extensions were thick-walled with clavate to naviculate vesicles. Conidia measured 12.7 to 17.1 (14.9) × 2.2 to 3.3 (2.7) μm. The molecular studies confirmed the morphological identification. Genomic DNA was isolated from the mycelia. The rDNA internal transcribed spacer (ITS) region was amplified with the primers ITS1 and ITS4 and a part of the β-tubulin gene with the primers Bt2a and Bt2b (2). The sequences generated in this study were compared with sequences obtained from GenBank. A BLAST analysis showed that the ITS sequence had a 99% similarity with that of C. parva GenBank Accession No. AY793454 and the β-tubulin gene had a 100% similarity with AY793489. So far, pathogenicity of C. parva has been demonstrated for only a few plant species. Its pathogenicity was confirmed on grapevine (Vitis vinifera) in New Zealand (3), on common oak (Quercus robur) in Italy (4), and on eucalyptus in South Africa (1). To fulfill Koch's postulates for the pathogen on E. fortunei, the isolate JKI 2188 of C. parva was inoculated on 40 two-year-old plants of cv. Emerald 'n Gold. The leaves around one node were removed on five shoots per plant. After wounding the nodes with a needle, colonized agar plugs were placed on them. The plugs were covered with moist cellulose swabs and sealed with Parafilm. To act as negative controls, 20 plants were treated with sterile agar plugs. All the plants were incubated in a growth chamber at 21/16°C (day/night), with a day length of 12 h and a relative humidity of 90 to 100%. Seven weeks after inoculation, all inoculated plants showed symptoms identical to those of the diseased plants from which C. parva was originally isolated. The negative controls remained healthy. The strains reisolated were identical to the original isolates. To our knowledge, this is the first report of C. parva as a pathogen of Euonymus. Since 2011, there were no further reports of this disease. At present, the disease is not of economic importance. References: (1) P. W. Crous et al. Plant Pathol. 42:302, 1993. (2) N. L. Glass and G. C. Donaldson. Appl. Environ. Microbiol. 61:1323, 1995. (3) E. E. Jones et al. Plant Dis 96: 144, 2012. (4) L. Scattolin and L. Monteccio. Plant Dis. 91:771, 2007.

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Occurrence of Grapevine Declines and First Report of Black Dead Arm Associated with Botryosphaeria obtusa in Lebanon

Plant Disease ◽

10.1094/pd-90-0115a ◽

2006 ◽

Vol 90 (1) ◽

pp. 115-115 ◽

Cited By ~ 7

Author(s):

E. Choueiri ◽

F. Jreijiri ◽

P. Chlela ◽

G. Louvet ◽

P. Lecomte

Keyword(s):

Morphological Characteristics ◽

Aerial Mycelium ◽

Cabernet Sauvignon ◽

Polymerase Chain Reaction Primer ◽

First Report ◽

Phaeomoniella Chlamydospora ◽

Central Necrosis ◽

Eutypa Dieback ◽

Botryosphaeria Obtusa ◽

Black Dead Arm

Grapevine, cultivated mostly in the Bekaa Plain, is one of the most important fruit crops in Lebanon. During July 2004, a survey was made in 11 vineyards of local table or wine grapes to evaluate the sanitary status of the grapevine industry as far as wood declines are concerned. The most common grapevine decline was esca. The two forms of the disease (mild and severe) were observed. The mild form was characterized by leaf symptoms consisting of interveinal necrotic spots with yellow or red chlorotic blotches on white and red cultivars. The severe form was characterized by dieback of one or more shoots, leaf drop, shrivelling, and drying of fruit clusters. In west Bekaa, on cv. Cabernet Sauvignon, some vines showed symptoms identical to those of Eutypa dieback such as stunted chlorotic shoots with small, distorted leaves; moreover, symptoms corresponding to black dead arm (BDA) such as wine red spots on the margins of leaves and dry spots were seen as reported earlier (1). Diseased vines of various cultivars were collected: 10 Cabernet Sauvignon (7 esca, 3 BDA, and 1 Eutypa dieback), 4 Beitamouni, 3 Carignan, 2 Teifihi, 1 Zeitouni, 1 Mourverdre, 1 Caladoc, and 1 Merlot. In wood, cross sections through the trunk were made that showed mainly central necrosis, white heart rot, brown red wood, and black spotting. Wedge-shaped lesions were the least common. Particularly for BDA, peeling off the bark revealed a brown streaking of the external wood. Isolations were made on malt agar (MA) with wood chips cut from the different necroses described above. Fungal identifications were based on morphological characteristics in comparison with French isolates after subculturing at 20 to 22°C: Fomitiporia sp. (F85-1), Phaeomoniella chlamydospora (F85-2), Eutypa lata (BX1-10, 8D, and 8F), and Botryosphaeria obtusa (F99-1). The fungus most frequently isolated from central necrosis with white heart rot was the basidiomycete Fomitiporia sp. (35% of vines). Cultures of Fomitiporia sp. on MA reached 4 to 5 cm in diameter after 2 weeks and were yellowish to brownish without conidia. P. chlamydospora (associated with esca, black goo, or Petri disease) was isolated from only 9% of vines investigated. Cultures of P. chlamydospora on MA were slow growing and reached 7 to 8 mm in diameter in the dark after 8 days. Colonies were white but became light green and later became dark green. Sporulation was abundant. E. lata (causing Eutypa dieback) was isolated from the vine of cv. Cabernet Sauvignon showing typical symptoms and from two vines showing symptoms of esca only. Two strains produced characteristic pycniospores, and all strains were identified using polymerase chain reaction (Primer Scar 10A-10B) (2). Among the saprophytic fungi isolated from the different kinds of necroses, either central, wedge-shaped, or under the bark, B. obtusa associated with BDA was found most commonly (65% of vines). Cultures of B. obtusa were gray brown with dense aerial mycelium. Pycnidia started to form after 4 to 5 days and conidia (20 to 26 × 9 to 16 μm) were dark brown when mature. These results are consistent with previous descriptions. To our knowledge, this is the first report of black dead arm in Lebanon. References: (1) P. Larignon et al. Phytopathol. Mediterr. 40:S336, 2001. (2) P. Lecomte et al. Appl. Environ. Microbiol. 66:4475, 2000.

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First Report of Canker Disease Caused by Neofusicoccum australe on Eucalyptus and Pistachio in Spain

Plant Disease ◽

10.1094/pdis-92-6-0980b ◽

2008 ◽

Vol 92 (6) ◽

pp. 980-980 ◽

Cited By ~ 15

Author(s):

J. Armengol ◽

D. Gramaje ◽

A. Pérez-Sierra ◽

E. Landeras ◽

R. Alzugaray ◽

...

Keyword(s):

Dna Sequences ◽

Elongation Factor ◽

Stem Canker ◽

Malt Extract ◽

Northern Spain ◽

Internal Transcribed Spacer Region ◽

Canker Disease ◽

First Report ◽

Inoculation Site ◽

Mycelial Plug

In 2005 and 2006, dieback and branch cankers were observed in 12-year-old Eucalyptus globulus Labill. plantations in Gijón (northern Spain) and a 20-year-old pistachio (Pistacia vera L.) plantation in Constantí (northeastern Spain). Isolations were made from symptomatic branches. Small pieces of necrotic tissues were surface sterilized for 1 min in 1.5% NaOCl and plated onto malt extract agar amended with 0.5 g L–1 streptomycin sulfate. Plates were incubated at 25°C in the dark and all growing colonies were transferred to potato dextrose agar (PDA). A Neofusicoccum sp. was consistently isolated from necrotic tissues of both host species. On PDA at 25°C, isolates developed a moderately dense mycelium, initially with a pale yellow pigment diffusing into the medium but becoming olivaceous gray after 5 to 6 days. Pycnidia were produced on sterile eucalyptus and pistachio twigs placed on the surface of water agar after 1 month. Conidia were hyaline, fusiform, aseptate, with granular contents. Conidia from eucalyptus isolates measured (22.5–) 25.4 (–28.1) × (5–) 6.2 (–7.5) μm, (n = 40) and (20.0–) 23.6 (–28.0) × (6.5–) 7.1 (–8.0) μm, (n = 40) from pistachio isolates. Isolates were identified as Neofusicoccum australe (Slippers, Crous & M.J. Wingf.) Crous, Slippers & A.J.L. Phillips (1,2). DNA sequences of the rDNA internal transcribed spacer region (ITS), part of the beta-tubulin (BT2), and part of the translation elongation factor 1-alpha (EF1-α) genes from isolates CBS 122027 (pistachio) and CBS 122026 and CBS 122025 (eucalyptus) were used to confirm the identifications through BLAST searches in GenBank. Representative sequences of all studied regions were deposited in GenBank (ITS: EU375516 and EU375517; BT2: EU375520; EF1-α: EU375518 and EU375519). Pathogenicity tests were conducted on 8-month-old eucalyptus seedlings and 2-year-old pistachio plants with the three N. australe strains mentioned above. A mycelial plug taken from the margin of an actively growing colony of each isolate was put in a shallow wound (0.4 cm2) made with a scalpel on the stem of each plant. Inoculation wounds were wrapped with Parafilm. Controls were inoculated with sterile PDA plugs. Ten replicates for each isolate and plant species were used, with an equal number of control plants. Plants were maintained in a greenhouse at 25°C. After 3 weeks, all eucalyptus seedlings showed leaf wilting, stem canker, and pycnidia formation around the inoculation site. No foliar symptoms were observed in pistachio plants after 3 months, but depressed cankers variable in size and pycnidia formation developed around the inoculation site. Vascular necroses that developed on the inoculated plants were 10.2 ± 1.2 cm long in eucalyptus and 6.4 ± 1.6 cm long in pistachio, significantly greater than their respective controls (P < 0.01). There were no significant differences in necrosis lengths among the three N. australe isolate inoculations, irrespective of the inoculated host. These results point to a high susceptibility of eucalyptus to N. australe. No symptoms were visible in the control seedlings and no fungus was isolated from them. The pathogen was reisolated from all inoculated plants. To our knowledge, this is the first report of N. australe causing canker disease on eucalyptus and pistachio trees in Spain. References: (1) P. Crous et al. Stud. Mycol. 55:235, 2006. (2) B. Slippers et al. Mycologia 96:1030, 2004.

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First Report of Cylindrocarpon pauciseptatum Associated with Grapevine Decline from Castilla y León, Spain

Plant Disease ◽

10.1094/pdis-10-10-0750 ◽

2011 ◽

Vol 95 (3) ◽

pp. 361-361 ◽

Cited By ~ 5

Author(s):

M. T. Martin ◽

L. Martin ◽

M. J. Cuesta ◽

P. García-Benavides

Keyword(s):

Morphological Characteristics ◽

Vascular Lesions ◽

Width Ratio ◽

Morphological Identification ◽

Malt Extract ◽

Internal Transcribed Spacer Region ◽

Current Season ◽

First Report ◽

Grapevine Decline ◽

Agar Plug

During a survey for grapevine decline, 10 young grapevines (cvs. Tempranillo and Verdejo) with low vigor and little foliage were collected between June 2008 and August 2009. Small pieces of vascular and brown wood were placed onto malt extract agar supplemented with 0.25 g/liter of chloramphenicol and incubated at 25°C. Fifteen resulting colonies were transferred to potato dextrose agar in petri dishes (90 mm). Colonies with white mycelium covered the dishes after 10 days of incubation at 25°C in darkness; mycelium gradually became yellowish with some brownish aspect. Macroconida were predominantly three septate (40 to 45 to 50 × 8.6 to 9 to 9.5 μm with a length and width ratio of 4.7 to 5 to 5.4), straight, and cylindrical with both ends broadly rounded. Chlamydospora and ovoidal microconidia were observed on synthetic nutrient-poor agar (1). Cylindrocarpon pauciseptatum was not easy to distinguish from other Cylindrocarpon species based on morphological characteristics. Ribosomal internal transcribed spacer region sequences of single-spore cultures confirmed the morphological identification and revealed 100% genetic identity with other isolates of C. pauciceptatum present in GenBank (EF607090), a sequence of the fragment was deposited with Accession No. EU983277. Pathogenicity tests were conducted with two isolates. The inoculations were done on 110R rootstock wood of four different young plants and 15 detached canes of current-season growth (cv. Tempranillo). Plants were inoculated with an agar plug containing C. pauciceptatum; controls were treated with agar only. Grapevines were maintained in a greenhouse at 20 to 25°C. After 3 to 4 months, C. pauciceptatum was reisolated from brown tissues and internal vascular lesions in 45% of inoculated samples, fulfilling Koch's postulates. Control plants were asymptomatic and C. pauciceptatum was not recovered. To our knowledge, this is the first report implicating C. pauciceptatum as a cause of grapevine black foot disease in Spain with potentially significant impact on grapevine nurseries. Reference: (1) H. J. Schroers et al. Mycol. Res. 112:82, 2008.

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First Report of Cylindrocladiella parva and C. peruviana Associated with Black-foot Disease of Grapevine in Spain

Plant Disease ◽

10.1094/pdis-04-12-0410-pdn ◽

2012 ◽

Vol 96 (9) ◽

pp. 1381-1381 ◽

Cited By ~ 4

Author(s):

C. Agustí-Brisach ◽

S. Alaniz ◽

D. Gramaje ◽

A. Pérez-Sierra ◽

J. Armengol ◽

...

Keyword(s):

Peat Moss ◽

Vitis Vinifera L ◽

Post Inoculation ◽

Malt Extract ◽

Wheat Seed ◽

High Similarity ◽

First Report ◽

Foot Disease ◽

Black Foot ◽

Black Foot Disease

From 2007 to 2009, Cylindrocladiella-like isolates were recovered from grapevine (Vitis vinifera L.) roots with symptoms of black-foot disease in Spain, where the causal agents of this disease have been previously reported as Campylocarpon and Cylindrocarpon species (1,2). Three representative isolates were selected to confirm their identity: CPa1 and CPa2 from Asturias (northern Spain), and CPe523 from Cuenca (central Spain). Isolates were incubated on malt extract agar (MEA) and Spezieller Nährstoffarmer Agar (SNA) with carnation leaves (4) at 25°C for 10 days in darkness. On MEA, colonies developed light brown, cottony mycelium. On SNA, all three isolates produced chlamydospores in chains, and conidia were zero-to one-septate, but CPa1 and CPa2 produced longer conidia (10.4 to 18.9 [15.3] × 1.7 to 3.1 [2.4] μm) than CPe523 (6.4 to 12.3 [9.7] × 1.6 to 3.3 [2.4] μm). A fragment of the beta-tubulin gene from all isolates was sequenced with primers T1 and Bt2b (1) and deposited in GenBank (Accession Nos. JQ693133, JQ693134, and JQ693135). CPa1 and CPa2 showed high similarity (99%) to Cylindrocladiella parva (AY793486) and CPe523 showed high similarity (99%) to C. peruviana (AY793500), which is in agreement with the corresponding morphological features of these species (4). Pathogenicity tests were conducted with inoculum produced on wheat (Triticum aestivum L.) seed soaked for 12 h in 300 ml of distilled water and autoclaved three times. Inoculum was prepared by inoculating two fungal disks (8 mm in diameter) of a 2-week-old culture of each isolate grown on potato dextrose agar to wheat seed and incubation at 25°C for 4 weeks. One-month-old grapevine seedlings were planted individually in 220-cc pots filled with a potting medium of sterilized peat moss and 10 g of inoculum, and grown in the greenhouse at 25°C in a completely randomized design. Controls were inoculated with sterile, noninoculated wheat seed. There were six replicate plants per isolate, with an equal number of controls, and the experiment was repeated once. Symptoms developed in all plants by 20 days post-inoculation and consisted of reduced vigor, necrotic root lesions, and occasionally mortality, all of which resembled the symptoms from grapevines in the field from which the isolates were originally recovered. Mean shoot dry weights of inoculated plants (0.25, 0.16, and 0.28 g for CPa1, Cpa2, and CPa523, respectively) were significantly lower (P < 0.05) than that of the controls (0.74 g). Mean root dry weights of inoculated plants (0.28, 0.16, and 0.29 g for CPa1, Cpa2, and CPa523, respectively) were also significantly lower (P < 0.05) than that of the controls (0.68 g). Isolates recovered from the roots of inoculated plants were identical morphologically and molecularly to C. parva and C. peruviana, thereby satisfying Koch's postulates. No symptoms were observed on the control plants. These Cylindrocladiella spp. have been reported from nurseries or vineyards in South Africa and New Zealand (3). To our knowledge, this is the first report of C. parva and C. peruviana associated with black-foot disease of grapevine in Spain, and in Europe. References: (1) S. Alaniz et al. Plant Dis. 91:1187, 2007. (2) S. Alaniz et al. Plant Dis. 95:1028, 2011. (3) E. E. Jones et al. Plant Dis. 96:144, 2012. (4) L. Lombard et al. Mycol. Progress DOI 10.1007/s11557-011-0799-1, 2012.

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Sistemas atmosféricos em Santa Catarina no período da maturação à colheita de videira Cabernet Sauvignon

Agrometeoros ◽

10.31062/agrom.v25i2.23591 ◽

2018 ◽

Vol 25 (2) ◽

Author(s):

Cristina Pandolfo ◽

Marilene De Lima ◽

Angelo Mendes Massignam ◽

Aparecido Lima da Silva ◽

Luiz Albano Hammes

Keyword(s):

Vitis Vinifera ◽

Vitis Vinifera L ◽

Cabernet Sauvignon ◽

Santa Catarina

Os sistemas atmosféricos exercem um papel significativo no clima de uma região e poucos trabalhos determinaram os impactos dos sistemas atmosféricos no desenvolvimento e na produção de videira. Os objetivos deste trabalho foram determinar a frequência de ocorrência dos sistemas atmosféricos durante o período da maturação à colheita da videira (Vitis vinifera L.) var. Cabernet Sauvignon para as duas regiões produtoras de Santa Catarina em diferentes safras e determinar a associação entre a ocorrência dos sistemas atmosféricos e as regiões produtoras e as safras. Os sistemas atmosféricos foram identificados durante as safras de 2005/2006 à 2008/2009. Os municípios de Água Doce e Campos Novos foram escolhidos para representar a região produtora 1 e os municípios de Bom Retiro e São Joaquim para representar a região produtora 2. As frequências de ocorrências dos sistemas atmosféricos durante o período da maturação à colheita de videira são muito semelhantes entre as regiões, somente houve diferença na frequência de ocorrência do sistema jato subtropical entre regiões. Houve uma diferença significativa da ocorrência da frequência dos sistemas atmosféricos entre safras.

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