Mycotoxigenic potential and pathogenicity of Fusarium species isolated from sugar beet

2011 ◽  
Author(s):  
Daniela Christ ◽  
Mark Varrelmann
Keyword(s):  
Sugar Beet ◽  
Fusarium Species

scholarly journals Damping-off of sugar beet in Finland: I. Causal agents and some factors affecting the disease

1982 ◽  
Vol 54 (4) ◽  
pp. 225-244
Author(s):  
Mauritz Vestberg ◽  
Risto Tahvonen ◽  
Kyösti Raininko
Keyword(s):  
Sugar Beet ◽  
Fusarium Species ◽  
Damping Off ◽  
Fusarium Spp ◽  
Factors Affecting ◽  
Pathogenicity Tests ◽  
Phoma Betae

The fungus Pythium debaryanum auct. non Hesse is the main cause of damping-off on sugar beet in Finland. The fungus is found especially in diseased seedlings during the first two weeks after emergence. Later on, when the plants have one or two pairs of true leaves, Fusarium spp. can be isolated to a rather great extent. However, pathogenicity tests with three different Fusarium species have shown that this fungus is unble cause damping-off on sugar beet when inoculated into peat substrate. Among the fungi tried in this respect, only Pythium debaryanum and Phoma betae Frank showed clear pathogenicity. Sugar beet seedlings that outlive the disease grow slower, and their quality at harvest in the autumn is poorer than that of healthy beets.

scholarly journals Stalk Rot of Sugar Beet Caused by Fusarium solani on the Pacific Coast

Plant Disease ◽  
2007 ◽  
Vol 91 (9) ◽  
pp. 1204-1204 ◽  
Author(s):  
L. E. Hanson ◽  
R. T. Lewellen
Keyword(s):  
Sugar Beet ◽  
Seed Production ◽  
Fusarium Species ◽  
Lesion Size ◽  
Negative Control ◽  
Vascular Bundles ◽  
Water Control ◽  
The Pacific ◽  
Salinas Valley ◽  
Pathogenicity Tests

In 2006, symptoms of stalk blight (2) were observed on sugar beet (Beta vulgaris L.) plants from roots produced in Oregon that were being grown for seed production in a greenhouse in Salinas, CA using Salinas Valley soil. Symptoms included vascular and cortical browning, necrosis, and death of seed stalks. Isolations were made from the edge of stalk lesions and the crown. In addition to Fusarium oxysporum, the known cause of stalk blight (2), two isolates of F. solani were identified by morphology. For pathogenicity tests, sugar beet plants (FC606 [4]), grown in pasteurized potting mix and induced to flower by exposure at 4 to 7°C for 90 days (1) were used. Bolting plants were maintained in a greenhouse at 24 to 27°C. A 100-μl drop of a spore suspension (104 spores per ml) of each Fusarium isolate was placed on the surface of the seed stalk. The plant was stabbed through the drop with a sterile 18-gauge needle so that the drop was taken into the plant by hygroscopic pressure. Positive and negative control treatments were a stalk blight isolate of F. oxysporum from an Oregon seed production field and sterile water, respectively. Three plants were inoculated per isolate. Each inoculation site was wrapped loosely in Parafilm for 1 week to maintain a high humidity level around the site of inoculation, and seed stalks were covered in cloth bags (1). After 1 week, the Parafilm was removed and plants were examined weekly for symptoms. At 4 weeks, lesion size was measured. After 5 weeks, sections were taken from the seed stalk around the site of inoculation, surface disinfested with 0.5% NaOCl, and plated on potato dextrose agar to confirm the presence of the pathogen. The experiment was done twice. One of the two isolates of F. solani caused dark brown lesions on all inoculated seed stalks. On one plant, at 4 weeks after inoculation when the bag was being removed for observation, the seed stalk broke at the site of inoculation because of a spreading, brown lesion at the site. No lesions were observed on the water control plants. Brown lesions were observed on seed stalks inoculated with the known stalk blight isolate. Lesions were significantly (P = 0.001) larger with F. oxysporum than with F. solani when measured at 4 weeks (mean of 6.3 cm versus 2.2 cm, respectively). Lesions caused by F. solani showed a dark discoloration through the cortical tissue, as opposed to those caused by F. oxysporum, for which most of the initial discoloration was in the vascular bundles and epidermis. Fusarium isolates recovered from inoculated plants were morphologically similar to the isolates used for inoculation. Fusarium spp. were not isolated from the water control plants. While some F. solani isolates cause seedling or mature root disease in sugar beet (3), to our knowledge, this is the first report of a Fusarium species other than F. oxysporum causing a rot of sugar beet stalks. References: (1) E. Biancardi et al. Genetics and Breeding of Sugar Beet Science Publishers, Inc., Enfield, NH, 2005. (2) A. N. Mukhopadhay. Handbook of Diseases of Sugar Beet, Vol. 1. CRC Press, Boca Raton, FL 1987. (3) E. G. Ruppel. Plant Dis. 75:486, 1991. (4) G. A. Smith and E. G. Ruppel. Crop Sci. 19:300, 1980.

scholarly journals First Report of Fusarium oxysporum Causing Yellows on Sugar Beet in the Red River Valley of Minnesota and North Dakota

Plant Disease ◽  
2005 ◽  
Vol 89 (3) ◽  
pp. 341-341 ◽  
Author(s):  
C. E. Windels ◽  
J. R. Brantner ◽  
C. A. Bradley ◽  
M. F. R. Khan
Keyword(s):  
Sugar Beet ◽  
North Dakota ◽  
Vascular Tissue ◽  
Fusarium Species ◽  
River Valley ◽  
Red River ◽  
State University ◽  
Water Control ◽  
First Report ◽  
Red River Valley

In 2002, somel sugar beet (Beta vulgaris L.) fields in the Red River Valley (RRV) of Minnesota and North Dakota had symptoms characteristic of Fusarium yellows (4). In 2004, ≈5% of fields in the RRV had symptomatic plants. Interveinal yellowing of older leaves typically began in mid-July and as the disease progressed, younger leaves turned yellow. Sometimes, one side of the leaf was yellow or necrotic while the other side remained green. As leaves died, they remained attached to the crown. Transverse sections of roots revealed a light gray-brown discoloration of the vascular tissue but no external rotting of roots. Isolations from 35 symptomatic roots collected in eight fields yielded 25 isolates identified as F. oxysporum (from single conidia grown on homemade potato dextrose agar and carnation leaf agar) (3). Pathogenicity was determined by dipping roots of 5-week-old sugar beet plants (cv. ACH 9363) in a suspension of 104 conidia per ml for 8 min (12 isolates, 10 to 12 plants per isolate). Plants were planted in Cone-tainers (3.8 cm diameter × 21 cm; Stuewe and Sons, Inc. Corvallis, OR) containing sterile soil. Three known cultures of F. oxysporum Schlecht. emend. Snyd. & Hans. f. sp. betae Stewart (= F. conglutinans var. betae Stewart [4]) also were included (13 and 216c from L. Hanson, USDA-ARS, Fort Collins, CO; 0-1122 from The Pennyslvania State University Fusarium Research Center). The control was sterile water. Plants were placed in a greenhouse at 24 to 27°C with natural light supplemented with illumination from high-pressure sodium-vapor lamps for 16 h daily and lightly fertilized biweekly to avoid chlorosis from nutrient deficiency. After 6 to 7 weeks, plants were rated for disease on a 0 to 4 scale: 0 = no disease; 1 = slight to extreme plant stunting, leaves may be wilted; 2 = chlorotic leaves, some with necrosis at margins; 3 = tap root dried and brown to black in color, leaves dying; and 4 = plant dead (1). The experiment was repeated. Disease severity differed between trials, but all isolates of F. oxysporum and F. oxysporum f. sp. betae resulted in disease ratings statistically (P < 0.05) greater than that of the water control. In Trial 1, isolates of F. oxysporum averaged a rating of 2.1 (range of 1.8 to 3.3) and F. oxysporum f. sp. betae averaged 2.1 (range of 2.0 to 2.2) compared with 0.1 for the water control. One isolate of F. oxysporum had a statistically higher rating than did the cultures of F. oxysporum f. sp. betae. In Trial 2, isolates of F. oxysporum averaged a rating of 3.3 (range of 2.7 to 3.7) and F. oxysporum f. sp. betae averaged 3.1 (range of 2.7 to 3.4) compared with 0.2 for the water control. Cultures of F. oxysporum (8 of 12) resulted in ratings statistically higher than that of the least pathogenic culture of F. oxysporum f. sp. betae. Cultures of F. oxysporum and F. oxysporum f. sp. betae recovered from inoculated plants were identical to those used to inoculate plants. To our knowledge, this is the first report of F. oxysporum f. sp. betae on sugar beet in the Red River Valley of Minnesota and North Dakota. The disease has been reported in California, Colorado, Montana, Nebraska, Oregon, Texas, and Wyoming (1,2). References: (1) R. A. Cramer et al. J. Phytopathol. 151:352, 2003. (2) G. A. Fisher and J. S. Gerik. Phytopathology 84:1098, 1994. (3) P. E. Nelson et al. Fusarium Species: An illustrated Manual for Identification. The Pennsylvania State University Press. University Park, 1983. (4) D. Stewart. Phytopathology 21:59, 1931.

scholarly journals First Report of a Novel Fusarium Species Causing Yellowing Decline of Sugar Beet in Minnesota

Plant Disease ◽  
2008 ◽  
Vol 92 (11) ◽  
pp. 1589-1589 ◽  
Author(s):  
V. Rivera ◽  
J. Rengifo ◽  
M. Khan ◽  
D. M. Geiser ◽  
M. Mansfield ◽  
...  
Keyword(s):  
United States ◽  
Sugar Beet ◽  
Fusarium Species ◽  
Early Death ◽  
The United States ◽  
Yield Reduction ◽  
Natural Occurrence ◽  
The Novel ◽  
Sugar Beets ◽  
Potato Dextrose Agar Medium

In the United States, yellows disease of sugar beet (Beta vulgaris), which causes wilt, early death, and yield reduction, is caused primarily by Fusarium oxysporum f. sp. betae (3,4), but F. graminearum (2) has also been implicated. During the past 3 years, a similar disease causing yellowing and severe decline appeared in some sugar beet fields of central and southwest Minnesota planted with cultivars resistant to yellows. The disease has become a concern to the local sugar beet industry, which produces 56% of sugar beets in the United States. From 2005 to 2007, isolations were made from sugar beets collected in commercial fields and from a Fusarium screening nursery showing symptoms of yellowing, interveinal chlorosis, scorching, stunting, vascular discoloration of the taproot, and early death of plants. Of 96 Fusarium isolates recovered and used in root-dip inoculation trials in the greenhouse, 58 were pathogenic to sugar beets. On the basis of morphology, 12 were identified as F. oxysporum, 6 as F. graminearum, and 40 as a novel Fusarium species. The remaining 38 isolates were nonpathogenic. All three pathogenic Fusarium species were isolated from taproots, but only the novel Fusarium was isolated from petioles. In culture, the novel Fusarium exhibited a bright orange color on the underside of potato dextrose agar medium and produced micro- and macroconidia sparsely. Hyphal tip isolates of all novel Fusarium isolates were pathogenic, causing typical yellowing symptoms and plant death to the Fusarium yellows susceptible sugar beet cv. VDH46177 in replicated greenhouse trials. Isolates were successfully reisolated from the symptomatic plants, fulfilling Koch's postulates. Restriction fragment length polymorphism (RFLP) endonuclease digestion patterns (Alu1, Fnu4HI, HaeIII, and HhaI) of the internal transcribed spacer (ITS) region of 40 pathogenic novel isolates showed a distinct pattern compared with known Fusarium species. Thin layer chromatography analysis of 13 novel isolates detected the type A trichothecenes neosolaniol and 4,15-diacetoxyscirpenol. Partial sequences of the translation elongation factor 1-α (TEF) from 12 single-spored novel Fusarium isolates were generated. BLAST analysis of the TEF sequence against the FUSARIUM-ID (1) and GenBank databases did not match any known Fusarium species. On the basis of pathogenicity, morphology, RFLP patterns, mycotoxin production, and TEF sequence analysis it appears that this is a new species of Fusarium, but additional multilocus phylogenetic analyses are warranted. The natural occurrence of this novel Fusarium pathogen in sugar beet may have implications in breeding for resistance to Fusarium yellows, since yellow decline has been observed in purportedly Fusarium-tolerant cultivars in the Minnesota and North Dakota production regions. References: (1) D. M. Geiser et al. Eur. J. Plant Pathol. 110:473, 2004. (2) L. E. Hanson. Plant Dis. 90:686, 2006. (3). L. E. Hanson. Plant Dis. 90:1554, 2006. (4) C. E. Windels et al. Plant Dis. 89:341, 2005.

scholarly journals Comparative Pathogenicity and Virulence of Fusarium Species on Sugar Beet

Plant Disease ◽  
2012 ◽  
Vol 96 (9) ◽  
pp. 1291-1296 ◽  
Author(s):  
Pragyan Burlakoti ◽  
V. Rivera ◽  
G. A. Secor ◽  
A. Qi ◽  
L. E. Del Rio-Mendoza ◽  
...  
Keyword(s):  
Sugar Beet ◽  
Fusarium Oxysporum ◽  
Fusarium Species ◽  
Field Studies ◽  
Fusarium Spp ◽  
Foliar Symptoms ◽  
Vascular Discoloration ◽  
Fusarium Sp ◽  
Bare Root ◽  
Highly Virulent

In all, 98 isolates of three Fusarium spp. (18 Fusarium oxysporum, 30 F. graminearum, and 50 Fusarium sp. nov.) obtained from sugar beet in Minnesota were characterized for pathogenicity and virulence on sugar beet in the greenhouse by a bare-root inoculation method. Among the 98 isolates tested, 80% of isolates were pathogenic: 83% of the F. oxysporum isolates, 57% of the F. graminearum isolates, and 92% of the Fusarium sp. nov. isolates. Symptoms varied from slight to moderate wilting of the foliage, interveinal chlorosis and necrosis, and vascular discoloration of the taproot without any external root symptoms. Among the pathogenic isolates, 14% were highly virulent and 12% were moderately virulent. Most of the highly virulent isolates (91%) and moderately virulent isolates (89%) were Fusarium sp. nov. All pathogenic isolates of F. graminearum and most pathogenic isolates (87%) of F. oxysporum were less virulent. In general, more-virulent isolates induced first foliar symptoms earlier compared with less-virulent isolates. This study indicates that both F. oxysporum and Fusarium sp. nov. should be used in greenhouse and be present in field studies used for screening and developing sugar beet cultivars resistant to Fusarium yellows complex for Minnesota and North Dakota.

scholarly journals First Report of Fusarium Yellows of Sugar Beet Caused by Fusarium oxysporum in Michigan

Plant Disease ◽  
2006 ◽  
Vol 90 (12) ◽  
pp. 1554-1554 ◽  
Author(s):  
L. E. Hanson
Keyword(s):  
Sugar Beet ◽  
Fusarium Oxysporum ◽  
Rating Scale ◽  
Vascular Tissue ◽  
Fusarium Species ◽  
Nutrient Deficiency ◽  
Negative Control ◽  
Potato Dextrose Agar ◽  
First Report ◽  
Tap Root

Fusarium yellows of sugar beet (Beta vulgaris L.), caused by Fusarium oxysporum Schlechtend.Fr. f. sp. betae (Stewart) Snyd & Hans., has been a long-term problem in the western United States (3) and recently was reported in Minnesota and North Dakota (4). This disease is typified by interveinal yellowing and wilting of the foliage. Roots have no external symptoms but show internal vascular discoloration. In 2005, 12 sugar beet roots from Michigan with yellows-type symptoms were received by the author. Isolations were made from the cortical and vascular tissue of the crown and tap root. Fusarium spp. isolates were obtained from 10 of the beets, and 16 isolates were identified as Fusarium oxysporum on the basis of morphology and pigmentation on potato dextrose agar and spores and phialides on carnation leaf agar (2). F. oxysporum isolates were tested for pathogenicity by dipping roots of 5-week-old susceptible sugar beet plants (FC716) in a suspension of 104 spores per ml for 8 min, 10 plants per isolate. Two known pathogenic isolates of F. oxysporum f. sp. betae, Fob13 and Fob216c (4), were used for comparison. For a negative control, plants were dipped in sterile water. Beets were planted in Cone-tainers (3.8 cm diameter × 21 cm) containing pasteurized potting mix. Plants were placed in a greenhouse at 24 to 27°C and fertilized with 15-30-15 fertilizer every 2 weeks to avoid chlorosis from nutrient deficiency. Plants were rated weekly for foliar symptoms for 6 weeks using a Fusarium yellows rating scale of 0 to 4 in which 0 = no disease and 4 = complete plant death (1). After the final rating, plants were removed from soil and the tap root examined for root symptoms. Root segments were surface disinfested with 0.5% sodium hypochlorite and cultured on potato dextrose agar to confirm presence of the pathogen. The experiment was done twice. Seven F. oxysporum isolates tested caused typical Fusarium yellows symptoms including interveinal yellowing, stunting, and wilting of inoculated plants. Pathogenic isolates were obtained from 7 of the 10 beets that yielded F. oxysporum. Symptoms were indistinguishable from those caused by Fob13 (average ratings ranged from 1.8 to 2.4) and milder than those caused by Fob216c (average rating 3.1). No interveinal chlorosis or wilting was observed on the control plants. Isolations from inoculated plants provided F. oxysporum cultures morphologically similar to those used in inoculation by the methods of Nelson et al. (2). No F. oxysporum was isolated from control plants. To my knowledge, this is the first report of F. oxysporum causing Fusarium yellows on beet in Michigan. References: (1) L. E. Hanson and A. L. Hill. J. Sugar Beet Res. 41:163, 2004. (2) P. E. Nelson et al. Fusarium species: An Illustrated Manual for Identification. The Pennsylvania State University Press, University Park, 1983. (3). C. L. Schneider and E. D. Whitney. Fusarium Yellows. Page 18 in: Compendium of Beet Diseases and Insects. C. L. Schneider and E. D. Whitney, eds. The American Phytopathological Society, St. Paul, MN, 1986. (4) C. E. Windels et al. Plant Dis. 89:341, 2005.

scholarly journals First Report of Fusarium equiseti Causing Seedling Death on Sugar Beet in Minnesota, USA

Plant Disease ◽  
2021 ◽  
Author(s):  
Mohamed Fizal Khan ◽  
Yangxi Liu ◽  
Md. Ziaur Rahman Bhuyian ◽  
Dilip Lashman ◽  
Zhaohui Liu ◽  
...  
Keyword(s):  
Sugar Beet ◽  
Fusarium Species ◽  
Morphological Characters ◽  
Root Tip ◽  
Economic Damage ◽  
Fluorescent Light ◽  
Conidial Suspension ◽  
Single Spore ◽  
Fusarium Equiseti ◽  
First Report

In May 2019, sugar beet (Beta vulgaris L.) seedlings with symptoms of wilting and root tip discoloration and necrosis were found in Moorhead (46.5507° N, 96.4208° W), Minnesota, USA. Roots of infected seedlings were surface sterilized with 10% bleach for 15 seconds, rinsed with sterile distilled water and cultured on water agar (MA Mooragar®, Inc, CA) for 3 days at 23 ± 2°C. Isolates were transferred to carnation leaf agar (CLA) and incubated at room temperature (22°C) under fluorescent light for 14 days. Abundant macroconidia were produced in sporodochia. Macroconidia were 5- to 7-septate, slightly curved at the apex, and ranged from 35 to 110 ×1.2 to 3.8 μm. No microconidia were produced. Chlamydospores with thick, roughened walls were observed in chains or in clumps, and were ellipsoidal or subglobose. Single spore was transferred from CLA to potato dextrose agar (HIMEDIA Laboratories, India) produced abundant white mycelium and was pale brown where the colony was in contact with the media. The morphological features of the isolates were consistent with Fusarium equiseti (Corda) Sacc. (Leslie and Summerell 2006, Li et al. 2015). Genomic DNAs (NORGEN BIOTEK CORP, Fungi DNA Isolation Kit #26200) of two representative isolates were used for polymerase chain reaction (PCR). The second largest subunit of RNA polymerase (RPB2) was amplified by PCR with primers 5f2/7cr (O’Donnell et al. 2010). The amplified PCR product was sequenced and deposited in GenBank (accession number MW048778). A BLAST search in Genbank and the Fusarium MLST database showed 100% sequence alignment to F. equiseti with accession MK077037.1 and NRRL 25795, respectively. Pathogenicity testing was done using three sugar beet seedlings (Hilleshög proprietary material, Hilleshög Seed, LLC, Halsey, OR 97348) at cotyledonary stage grown in a pot (4˝×4˝×6˝) with six replicates. Seedlings were inoculated with F. equiseti conidial suspension (104 conidia ml-1 for 8 minutes) by the root dip method (Hanson, 2006). Mock inoculated plants were dipped in sterile water. Inoculated and control plants were placed in the greenhouse at 25 ± 2°C, and 75 to 85% relative humidity. One week later, inoculated seedlings showed root tip tissue discoloration similar to those observed in the field and non-inoculated seedlings were symptomless. This study was repeated. The fungus was re-isolated from diseased roots and confirmed to be F. equiseti based on morphological characters. Fusarium equiseti was reported on freshly harvested and stored beet in Europe but was not found to be pathogenic (Christ et al. 2011). Strausbaugh and Gillen (2009) reported the association of F. equiseti and root rot of sugar beet but did not report pathogenicity. This pathogen is reported in several crops including edible beans that is grown in rotation with sugar beet in several production areas (Jacobs et al. 2018). The most important Fusarium species reported to cause significant economic damage to sugar beet include F. oxysporum and F. secorum (Secor et al. 2014, Webb et. al. 2012). The presence of another pathogenic Fusarium species in sugar beet will require monitoring to determine how widespread it is and whether current commercial cultivars are resistant. To our knowledge, this is the first report of F. equiseti causing disease on sugar beet seedlings in Minnesota, USA.

scholarly journals Damping-off of sugar beet with special reference to the fungus Pythium Pringsheim

1988 ◽  
Vol 60 (3) ◽  
pp. 159-178
Author(s):  
M. Vestberg
Keyword(s):  
Sugar Beet ◽  
High Temperatures ◽  
Seed Treatment ◽  
Disease Incidence ◽  
Fusarium Species ◽  
Systemic Fungicide ◽  
Second Phase ◽  
Damping Off ◽  
Short Term ◽  
Preceding Crop

In Finland damping-off of sugar beet can be divided into two distinct phases. The first phase begins with the germination of the seeds and continues until the first true leaves have developed. Under field conditions seedlings usually remain healthy up to about 1 week after emergence. Thereafter a sudden outbreak of damping-off may occur, resulting in rapid wilting and death of seedlings. During the second phase of the disease, when seedlings have one or more pairs of true leaves, disease does not always result in the death of the plant; plants may survive throughout the summer. At the pernicious phase of the disease the soil borne pathogen, Pythium debaryanum auct. non Hesse, is the most common causal agent, accounting in 1979—86 for 53.9 % (variation between years 18.3—90.1 %) of fungal isolations, and Fusarium species for 28.3 % (5.0—58.5 %). At seedling stages with one or more pairs of true leaves Fusarium spp. predominate accounting for 49.4 % (36.1—81.0 %) as compared to 23,9 % (2.9—37.8) for P. debaryanum. The importance of Fusarium species as true damping-off pathogens is, however, doubtful. The seed borne damping-off pathogen Phoma betae Frank was isolated only in 0 to 4 % and was not dependent on the stage of seedling development. Of the factors affecting damping-off, high temperatures were repeatedly shown to increase the disease. This, presumably was an effect especially on P. debaryanum, the aggressiveness of which is strongly increased at high temperatures. Pot experiments showed preceding crops of cereals to have the best disease-decreasing effect, both short-term (one growing period of preceding crop) and long-term (several growing periods of preceding crop) effect. Legumes kept the level of damping-off unchanged or even raised it, especially as a short-term effect. The influence of preceding crops varied in different soil types. Preceding crops also caused considerable fluctuations in inoculum density (0 to 3650 propagules/gram soil) and potential (0.2—16 IPU 50/gram soil) of Pythium. The correlation to damping-off of sugar beet was, however, poor. Seed treatment with the systemic fungicide hymexazol, especially when combined with thiram, prevented satisfactorily the pernicious type of damping-off. In many experiments this seed treatment repeatedly decreased disease incidence significantly, produced denser stands (7100—31200 numbers of beets more/hectare) and increased yield by 5—10 % on average.

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