scholarly journals First Report of Thiabendazole-Resistant Isolates of Fusarium sambucinum Infecting Stored Potatoes in Nova Scotia, Canada

Plant Disease ◽  
2001 ◽  
Vol 85 (9) ◽  
pp. 1030-1030 ◽  
Author(s):  
R. D. Peters ◽  
I. K. Macdonald ◽  
K. A. MacIsaac ◽  
S. Woodworth
Keyword(s):  
Nova Scotia ◽  
Solanum Tuberosum L ◽  
Fusarium Species ◽  
The United States ◽  
Postharvest Disease ◽  
Potato Tubers ◽  
Eastern Canada ◽  
Dry Rot ◽  
First Report ◽  
Petri Dishes

Fusarium dry rot is a significant postharvest disease of potato (Solanum tuberosum L.) and is often controlled by applying thiabendazole to tubers prior to storage. However, thiabendazole-resistant isolates of Fusarium spp. have been reported from Europe (2), the United States (1), and Canada (1,4). To address concerns, samples of potato tubers showing symptoms of dry rot caused by Fusariumspp. were collected from three storage bays in a commercial storage facility in Nova Scotia, Canada, in February 2001. All tubers had been treated with thiabendazole after harvest and prior to storage. Tubers were cut longitudinally, and small tissue samples (10 × 5 × 3 mm) were taken from the margins of internal necrotic regions with a sterile scalpel, surface-sterilized in 0.6% sodium hypochlorite for 15 s, rinsed twice in sterile distilled water (SDW), and blotted dry on sterile filter paper. Tissue pieces were plated on 0.5-strength potato dextrose agar (PDA) amended with tetracycline (0.05 g/liter) and streptomycin sulfate (0.1 g/liter). Petri dishes were incubated in the dark at 22°C for 4 to 7 days. After incubation, hyphal tips from the margins of actively growing isolates were removed with a sterile probe and plated on 0.5-strength PDA to generate pure cultures. Of 35 potato tubers examined, 10 (29%) yielded Fusarium isolates for further study. All 10 isolates were identified as F. sambucinum Fuckel according to Nelson et al. (3). Agar plugs (5 mm diameter) taken from the margins of 7- to 10-day-old cultures of F. sambucinum isolates were transferred to petri dishes containing 0.5-strength PDA amended with thiabendazole at 0, 1, 5, 10, 20, 50, or 100 mg/liter. Thiabendazole was prepared as a stock solution in SDW and added to molten agar after autoclaving. Cultures were grown in the dark for 7 days at 22°C, after which mycelial growth diameter was measured using digital calipers. Two measurements, along orthogonal diameters, were taken from each of three replicate plates for a total of six measurements per thiabendazole concentration. Means were calculated, and the diameter of the inoculation plug was subtracted from each mean. Calculated EC50 values (thiabendazole concentration inhibiting pathogen growth by 50%) were obtained by regression of the log of the chemical concentration against the corresponding probit of percent fungal inhibition. All isolates of F. sambucinum were resistant to thiabendazole, with EC50 values ranging from 7 to 82 mg/liter. Six isolates had EC50 values between 40 and 82 mg/liter. Control isolates of F. sambucinum, F. avenaceum, F. solani, and F. oxysporum were sensitive to thiabendazole, with EC50 values of <1 mg/liter. Although isolates of F. sambucinum resistant to thiabendazole have been recovered from eastern Canada (1,4), this is the first report of thiabendazole resistance in F. sambucinum isolates from tubers in commercial storage in the Annapolis Valley of Nova Scotia, Canada, a production region that concentrates on growing processing potatoes for the potato chip industry and is several hundred kilometers from other potato-growing regions of Prince Edward Island and New Brunswick. References: (1) A. E. Desjardins. Am. Potato J. 72:145, 1995. (2) G. A. Hide et al. Plant Pathol. 41:745, 1992. (3) P. E. Nelson et al. 1983. Fusarium Species: An Illustrated Manual for Identification . Pennsylvania State University Press, University Park, PA. (4) H. W. Platt. Phytoprotection 78:1, 1997.

scholarly journals First Report of Fusarium torulosum Causing Dry Rot of Seed Potato Tubers in the United States

Plant Disease ◽  
2011 ◽  
Vol 95 (9) ◽  
pp. 1194-1194 ◽  
Author(s):  
E. Gachango ◽  
W. Kirk ◽  
L. Hanson ◽  
A. Rojas ◽  
P. Tumbalam
Keyword(s):  
United States ◽  
Sodium Hypochlorite ◽  
Fusarium Species ◽  
The United States ◽  
Distilled Water ◽  
Potato Tubers ◽  
Dry Rot ◽  
Fusarium Dry Rot ◽  
Half Strength ◽  
Potato Dry Rot

Fusarium dry rot of potato (Solanum tuberosum L.) is a postharvest disease caused by several Fusarium species and is of worldwide importance. Thirteen species of Fusarium have been implicated in fungal dry rots of potatoes worldwide. Among them, eight species have been reported in the northern United States (2). In Michigan potato production, F. sambucinum was the predominant species reported to be affecting seed potato in storage and causing seed piece decay after planting (3). Some previous identifications of F. sambucinum as dry rot may have been F. torulosum since F. torulosum was previously classified within F. sambucinum (4). To further investigate this, dry rot symptomatic tubers were collected from Michigan seed lots in the summers of 2009 and 2010. Small sections from the margins of necrotic regions were cut with a scalpel, surface sterilized in 0.5% sodium hypochlorite for 10 s, rinsed twice in sterile distilled water, and blotted with sterile filter paper. The tissue pieces were plated on half-strength potato dextrose agar (PDA) amended with 0.5 g/liter of streptomycin sulfate and incubated at 23°C for 5 to 7 days. Cultures resembling Fusarium species were transferred onto water agar, and single hyphal tips from actively growing isolates were removed and plated either on carnation leaf agar (CLA) or on half-strength PDA to generate pure cultures. Among the Fusarium isolates obtained, five isolates were identified as F. torulosum (GenBank Accessions Nos. JF803658–JF803660). Identification was based on colony and conidial morphology on PDA and CLA, respectively. These features included slow growth (2.8 ± 0.2 cm in 5 days), white mycelium that became pigmented with age, narrow concentric rings, red or white pigmentation on agar, macroconidia (32.4 ± 0.4 μm average length) with five septa, a pointed apical cell, and a foot-shaped basal cell (4). The identity was confirmed through DNA extraction followed by amplification and sequencing of the translation elongation factor (EF-1α) gene region (1). The Fusarium-ID.v (1) and the NCBI database were used to obtain the closest match (99%) to previously sequenced materials (GenBank Accession No. AJ543611). Pathogenicity testing was done on disease-free potato tubers cv. Red Norland. Tubers were surface sterilized for 10 min in 0.5% sodium hypochlorite and rinsed twice in distilled water. Three tubers per isolate were injected with 20 μl of a conidial suspension (106 conidia/ml) made from F. torulosum cultures grown on PDA for 7 to 10 days. Control tubers were injected with 20 μl of sterile distilled water. All tubers inoculated with F. torulosum developed typical potato dry rot symptoms consisting of a brown and dry decay. There was no disease incidence on the control tubers. F. torulosum was reisolated from the symptomatic tubers. To our knowledge, this is the first report of F. torulosum causing potato dry rot in the United States. References: (1) D. Geiser et al. Eur. J. Plant Pathol. 110:473, 2004. (2) L. E. Hanson et al. Phytopathology 86:378, 1996. (3) M. L. Lacy and R. Hammerschmidt. Fusarium dry rot. Extension Bulletin. Retrieved from http://web1.msue.msu.edu/msue/iac/onlinepubs/pubs/E/E2448POT , 23 May 2010. (4) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Wiley-Blackwell, Hoboken, NJ, 2006.

scholarly journals Identification of Fusarium spp. Associated with Potato Tubers in Upper Egypt by Morphological and Molecular Characters

2019 ◽  
pp. 1-14 ◽  
Author(s):  
Youssuf A. Gherbawy ◽  
Mohamed A. Hussein ◽  
Eman G. A. El-Dawy ◽  
Nabila A. Hassany ◽  
Saad A. Alamri
Keyword(s):  
Solanum Tuberosum L ◽  
Fusarium Species ◽  
Correct Diagnosis ◽  
Potato Tubers ◽  
Fusarium Spp ◽  
Dry Rot ◽  
Upper Egypt ◽  
Fusarium Dry Rot ◽  
Global Population ◽  
Highly Virulent

Potato (Solanum tuberosum L.) is an important crop which holds promise for food security considering the global population growth rate. Fusarium dry rot is one of the most significant diseases of potato. To build up strategies for the control of this disease, it ought to be made primarily a correct diagnosis and identification of the pathogen. A total of 504 Fusarium isolates were recovered from potato tubers collected from Upper Egypt. Fusarium isolates were identified based on morphology and partial DNA sequencing of β-tubulin (TUB) genes. 62.5% of the isolates were identified as F. sambucinum, followed F. oxysporum (57.5%), then F. verticillioides (56.25%) and F. incarnatum (47.5%). All the tested Fusarium species were able to produce amylase. The pathogenicity of the isolates was tested by inoculation of healthy potato tubers; all of the tested isolates were pathogenic to healthy potato tubers. F. sambucinum had a highly virulent effect.

scholarly journals Incidence and Etiology of Postharvest Fungal Diseases Associated with Bulb Rot in Garlic (Alllium sativum) in Spain

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1063
Author(s):  
Laura Gálvez ◽  
Daniel Palmero
Keyword(s):  
Negative Impact ◽  
Fusarium Species ◽  
Fungal Species ◽  
Postharvest Disease ◽  
Dry Rot ◽  
Fusarium Dry Rot ◽  
Causative Agents ◽  
Postharvest Handling ◽  
Pathogenicity Tests ◽  
Bulb Rot

In recent years, different postharvest alterations have been detected in garlic. In many cases, the symptoms are not well defined, or the etiology is unknown, which further complicates the selection of bulbs during postharvest handling. To characterize the different symptoms of bulb rot caused by fungi, garlic bulb samples were collected from six Spanish provinces in two consecutive years. Eight different fungal species were identified. The most prevalent postharvest disease was Fusarium dry rot (56.1%), which was associated with six Fusarium species. Fusarium proliferatum was detected in more than 85% of symptomatic cloves, followed by F. oxysporum and F. solani. Pathogenicity tests did not show a significant correlation between virulence and mycotoxin production (fumonisins, beauvericin, and moniliformin) or the mycelial growth rate. Penicillium allii was detected in 12.2% of the samples; it was greatly influenced by the harvest season and garlic cultivar, and three different morphotypes were identified. Stemphylium vesicarium and Embellisia allii were pathogenic to wounded cloves. Some of the isolated fungal species produce highly toxic mycotoxins, which may have a negative impact on human health. This work is the first to determine the quantitative importance, pathogenicity, and virulence of the causative agents of postharvest garlic rot in Spain.

scholarly journals Resistance to thiabendazole in Fusarium species and Helminthosporium solani in potato tubers treated commercially in eastern Canada

2005 ◽  
Vol 78 (1) ◽  
pp. 1-10 ◽  
Author(s):  
H.W. Platt
Keyword(s):  
Prince Edward Island ◽  
Fusarium Species ◽  
Storage Period ◽  
Application Rate ◽  
Helminthosporium Solani ◽  
Fusarium Sambucinum ◽  
Potato Tubers ◽  
Eastern Canada ◽  
Wide Range ◽  
Tuber Rot

During the 1992-1993 and 1994-1995 winter storage period for potatoes (Solarium tuberosum) in Quebec, New Brunswick, and Prince-Edward-Island, tubers were collected which had symptoms of fusarium tuber rot and silver scurf and which had been treated commercially after harvest with thiabendazole. Resistance to thiabendazole was detected in isolates of Fusarium sambucinum and Helminthosporium solani but not in isolates of F. avenaceum and F. oxysporum. However, the majority of those farms surveyed (64%) had adequate disease control with no pathogen isolated from the diseased tubers. Incidence and EC50 values of resistant isolates were lower than found elsewhere and the occurrence of farms with resistant isolates of F. sambucinum (18%) was greater than for H. solani (7%). For H. solani, EC50 values of resistant isolates were substantially less than those found in Alberta. While the study investigated commercial operations employing a wide range of thiabendazole rates (6-42 g a.i. t-1), no specifie trends were detected between the occurrence of resistant isolates and cultivar or thiabendazole application rate.

Resistance to thiabendazole in Fusarium species isolated from potato tubers affected by dry rot

1992 ◽  
Vol 41 (6) ◽  
pp. 745-748 ◽  
Author(s):  
G. A. HIDE ◽  
P. J. READ ◽  
S. M. HALL
Keyword(s):  
Fusarium Species ◽  
Potato Tubers ◽  
Dry Rot

scholarly journals Parasitic nematodes in potatoes of different varieties and their interrelations with some arthropods

2021 ◽  
Vol 2 (3) ◽  
pp. 39-47
Author(s):  
Maria MELNIC ◽  
Olesea GLIGA ◽  
Dumitru ERHAN ◽  
Stefan RUSU ◽  
Elena IORDOSOPOL
Keyword(s):  
Solanum Tuberosum ◽  
Fungal Infections ◽  
Solanum Tuberosum L ◽  
Parasitic Nematodes ◽  
Potato Tubers ◽  
Dry Rot ◽  
Mole Cricket ◽  
The Republic ◽  
Ditylenchus Destructor

Introduction. Potato (Solanum tuberosum L.) is susceptible to infestation with an associated complex of different species of parasitic and saprophytic nematodes, bacteria, fungi, and arthropods, which diminish the quality of the product. Material and methods. 10 varieties of potatoes were investigated (Agata, Albastriu-mov, Bella rosa, Concorde, Desiree, Irga, Iagodca, Roko, Romano, Sprinter), cultivated on the territory of the Republic of Moldova. The extraction of nematodes and mites was performed using the Baermann funnels, modified by Nesterov.Results. Multiannual researches on the degree of potato infestation have shown that tubers are preferred by various arthropods (Acaridae), Agriothes spp. (Elateridae), Gryllotalpa gryllotalpa, (Grillotalpidae) and Sciaridae spp . (Sciaridae), which form different interactions with the parasitic nematodes of tubers (Ditylenchus destructor, D. dipsaci).Conclusions. Solanum tuberosum infested by parasitic nematodes D. destructor in association with saprophytic nematodes and dry rot are colonized by nematophag ous (mites – 80%) and phytophagous arthropods (wireworms – 40%; mole cricket – 50%; flies – 40%). Among the researched arthropods, Rhizoglyphus echinopus were more frequently found, which together with other species actively consume the primary and secondary parasitic nematodes, their mortality constituting up to 90%. In the traumatized by some arthropods potatoes, with the soil, secondary parasitic nematodes, also penetrate, carrying bacterial and fungal infections, subsequently stimulating the total rot of potato tubers.

Effect of Temperature on Aggressivity of Tunisian Fusarium species Causing Potato (Solanum tuberosum L.) Tuber Dry Rot

2006 ◽  
Vol 5 (2) ◽  
pp. 350-355 ◽  
Author(s):  
M. Daami-Rema ◽  
H. Jabnoun-Khiareddi . ◽  
F. Ayed . ◽  
M. El Mahjoub .
Keyword(s):  
Solanum Tuberosum ◽  
Solanum Tuberosum L ◽  
Fusarium Species ◽  
Effect Of Temperature ◽  
Dry Rot

scholarly journals First Report of Potato Stem Canker Caused by Rhizoctonia solani AG4 HGII in Gansu Province, China

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 840-840
Author(s):  
Y. G. Yang ◽  
X. H. Wu
Keyword(s):  
Rhizoctonia Solani ◽  
Solanum Tuberosum L ◽  
Its Region ◽  
Stem Canker ◽  
The United States ◽  
Gansu Province ◽  
Molecular Characteristics ◽  
Potato Seed ◽  
First Report ◽  
Wheat Seeds

Black scurf and stem canker on potato (Solanum tuberosum L.), caused by Rhizoctonia solani, is an important disease throughout the world. Isolates of R. solani AG3 are the principal cause of these diseases on potato (2). In August 2011, at the tuber bulking growth stage, symptoms typically associated stem canker, including dark brown stem lesions, were observed on 20% of potato plants collected from 23 locations (about 2,000 ha) in Gansu Province, northwest China. Stem pieces (each 5 mm long) taken from the margins of the healthy and diseased tissues were surface-disinfected with 0.5% NaOCl for 2 min, rinsed with sterilized water, dried, then placed on potato dextrose agar (PDA) at 25°C in the dark. Twenty-nine fungal isolates taken from single hyphal tips were identified as R. solani based on morphological traits, including mycelium branched at right angles with a septum near the branch and a slight constriction at the branch base. Hyphal cells were determined to be multinucleate (4 to 10 nuclei/cell) when stained with 4′-6-diamidino-2-phenylindole (DAPI). Anastomosis groups were determined by pairing with reference strains (kindly provided by N. Kondo, Hokkaido University, Japan), and three isolates (designed GS-15, GS-24, and GS-25) anastomosed with isolates of R. solani AG4. The internal transcribed spacer (ITS) region of rDNA was amplified from genomic DNA of each of the three isolates with primers ITS1 and ITS4. The resulting sequences (GenBank Accession Nos. JX843818, JX843819, and JX843820) were 100% identical to those of >10 R. solani AG4 HGII isolates (e.g., HQ629873.1; isolate ND13). Therefore, based on the anastomosis assay and molecular characteristics, the three isolates were identified as R. solani AG4 HGII. To determine pathogenicity of the AG4 HGII isolates, potato seed tubers (cv. Favorita) with 3 to 5 mm long sprouts were inoculated with wheat seeds (sterilized by autoclaving twice at 121°C for 1 h with a 24 h interval between autoclavings) colonized with each isolate (1). One sprouted tuber was planted in a sterilized plastic pot (1 liter) with a single colonized wheat seed placed 10 mm above the uppermost sprout tip in a sand/sawdust mixture (1:2 v/v, with dry heat sterilization at 161°C for 4 h before use). Plants were incubated in a glasshouse maintained at 25 to 27°C. The test was performed on 20 plants for each isolate, and the experiment was repeated. After 3 weeks, control plants inoculated with sterilized wheat seeds remained asymptomatic, and no Rhizoctonia spp. were isolated from these plants, whereas all inoculated plants showed symptoms of stem canker. R. solani AG4 HGII was reisolated consistently from symptomatic stems, and the identity of the reisolates confirmed by the morphological and molecular characteristics mentioned above, fulfilling Koch's postulates. Potato stem canker caused by R. solani AG4 HGII was reported previously in the United States (3). To our knowledge, this is the first report of R. solani AG4 HGII causing stem canker on potato in Gansu Province, the main potato-producing area of China. R. solani AG4 HGII can cause sheath blight on corn in China (4), which is commonly grown in rotation with potato. This rotation could increase the risk of soilborne infection to either crop by R. solani AG4 HGII. References: (1) M. J. Lehtonen et al. Plant Pathol. 57:141, 2008. (2) L. Tsror. J. Phytopathol. 158:649, 2010. (3) J. W. Woodhall et al. Plant Dis. 96:1701, 2012. (4) X. Zhou et al. J. Shenyang Agric. Univ. 43:33, 2012.

scholarly journals Alethopteris and Neuralethopteris from the lower Westphalian (Middle Pennsylvanian) of Nova Scotia and New Brunswick, Maritime Provinces, Canada

2020 ◽  
Vol 56 ◽  
pp. 111-145
Author(s):  
Carmen Álvarez-Vázquez
Keyword(s):  
United States ◽  
Nova Scotia ◽  
New Brunswick ◽  
Western Europe ◽  
The United States ◽  
Maritime Provinces ◽  
Eastern Canada ◽  
Systematic Revision ◽  
Insufficient Attention ◽  
The North

A systematic revision of Alethopteris and Neuralethopteris from upper Namurian and lower Westphalian (Middle Pennsylvanian) strata of Nova Scotia and New Brunswick, eastern Canada, has demonstrated the presence of eight species: Alethopteris bertrandii, Alethopteris decurrens, Alethopteris cf. havlenae, Alethopteris urophylla, Alethopteris cf. valida, Neuralethopteris pocahontas, Neuralethopteris schlehanii and Neuralethopteris smithsii. Restudy of the Canadian material has led to new illustrations, observations and refined descriptions of these species. Detailed synonymies focus on records from Canada and the United States. As with other groups reviewed in earlier articles in this series, it is clear that insufficient attention has been paid to material reposited in Canadian institutions in the European literature. The present study emphasizes the similarity of the North American flora with that of western Europe, especially through the synonymies.

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