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 ◽  
...  

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.

Plant Disease ◽  
2006 ◽  
Vol 90 (2) ◽  
pp. 247-247 ◽  
Author(s):  
L. E. Hanson ◽  
B. J. Jacobsen

A root-tip rot of sugar beet (Beta vulgaris L.) caused by Fusarium oxysporum Schlecht. emend. Snyd. & Hans. has been reported from Texas (2). This disease is typified by yellowing of the foliage, vascular discoloration, and a rot of the root tip. During 2002 and 2003, sugar beet samples from several fields in Colorado and Montana, some with tip rot symptoms, were received by the authors. Isolations were made from the root vascular tissue and tissue adjacent to the rot in Colorado and from the rot tissue in Montana. Isolates of Fusarium were obtained and identified as Fusarium oxysporum. At the ARS laboratory in Colorado, F. oxysporum isolates were tested for pathogenicity by dipping roots of 5-week-old sugar beet plants (FC716) in a suspension of 104 spores per ml for 8 min, 10 plants per isolate. One known isolate of F. oxysporum f. sp. betae that causes Fusarium yellows, Fob13, was used for comparison. For a negative control, plants were dipped in sterile water. Beets were planted in Cone-Tainers (3.8 cm in 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 with 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 the soil and the taproot was examined for rot symptoms. Root segments were surface disinfested with 0.5% sodium hypochlorite and cultured on potato dextrose agar to confirm the presence of the pathogen. The experiment was done twice. Six of ten F. oxysporum isolates tested caused root vascular discoloration and foliar symptoms, including interveinal yellowing and wilting, of inoculated plants. A rot of the root tip was observed on the roots of plants inoculated with three of the six pathogenic isolates. Isolate Fob13 caused only vascular discoloration and foliar symptoms with no rot. Similar experiments were done in Montana with the exception that 3-week-old plants (cv. Monohikari) were used and planted in 10-cm plastic pots with five seedlings per pot. Inoculum levels were 105 spores per ml of F. oxysporum f. sp. betae (isolate 216C) or tip rot isolates (3 isolates), and the experiments were terminated 4 weeks after planting. The root rot isolates caused foliar symptoms, vascular discoloration, and root rot similar to that seen in the field, whereas isolate 216C caused only foliar wilt symptoms and vascular discoloration. Isolations from inoculated plants in Colorado and Montana resulted in F. oxysporum cultures similar to those used in inoculation. To our knowledge, this is the first report of F. oxysporum causing root rot of sugar beet outside of Texas. References: (1) L. E. Hanson and A. L. J. Hill. Sugarbeet Res. 41:163, 2004. (2) R. M. Harveson and C. M. Rush. Plant Dis. 82:1039, 1998.


Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1955
Author(s):  
Anysia Hedy Ujat ◽  
Ganesan Vadamalai ◽  
Yukako Hattori ◽  
Chiharu Nakashima ◽  
Clement Kiing Fook Wong ◽  
...  

The re-emergence of the Fusarium wilt caused by Fusarium odoratissimum (F. odoratissimum) causes global banana production loss. Thirty-eight isolates of Fusarium species (Fusarium spp.) were examined for morphological characteristics on different media, showing the typical Fusarium spp. The phylogenetic trees of Fusarium isolates were generated using the sequences of histone gene (H3) and translation elongation factor gene (TEF-1α). Specific primers were used to confirm the presence of F. odoratissimum. The phylogenetic trees showed the rich diversity of the genus Fusarium related to Fusarium wilt, which consists of F. odoratissimum, Fusarium grosmichelii, Fusarium sacchari, and an unknown species of the Fusarium oxysporum species complex. By using Foc-TR4 specific primers, 27 isolates were confirmed as F. odoratissimum. A pathogenicity test was conducted for 30 days on five different local cultivars including, Musa acuminata (AAA, AA) and Musa paradisiaca (AAB, ABB). Although foliar symptoms showed different severity of those disease progression, vascular symptoms of the inoculated plantlet showed that infection was uniformly severe. Therefore, it can be concluded that the Fusarium oxysporum species complex related to Fusarium wilt of banana in Malaysia is rich in diversity, and F. odoratissimum has pathogenicity to local banana cultivars in Malaysia regardless of the genotype of the banana plants.


2004 ◽  
Vol 5 (1) ◽  
pp. 7 ◽  
Author(s):  
Cynthia M. Ocamb ◽  
Stephen C. Alderman

Seed samples were collected from 15 commercial tall fescue seed production fields and examined for Fusarium spp. The percentage of seeds from which Fusarium spp. were recovered ranged from 0 to 32%, while disinfesting seeds with 3% hydrogen peroxide reduced the recovery of Fusarium to 7% or less. The predominant Fusarium spp. isolated from the tall fescue seeds included F. avenaceum, F. culmorum, F. pseudograminearum, and F. sambucinum. Greenhouse inoculations of tall fescue panicles with F. avenaceum, F. culmorum, and F. pseudograminearum resulted in higher seedborne rates of each respective Fusarium sp. than that recovered from noninoculated plants. Seeds recovered from panicles treated with F. avenaceum or F. pseudograminearum had significantly lower germination rates relative to panicles sprayed with water or a suspension of F. culmorum. Our work confirms that Fusarium spp. decrease seed germination and expands the pathogen list to include F. avenaceum and F. pseudograminearum. Accepted for publication 17 February 2004. Published 19 March 2004.


2006 ◽  
Vol 96 (10) ◽  
pp. 1124-1133 ◽  
Author(s):  
Jane E. Stewart ◽  
Mee-Sook Kim ◽  
Robert L. James ◽  
R. Kasten Dumroese ◽  
Ned B. Klopfenstein

Fusarium species can cause severe root disease and damping-off in conifer nurseries. Fusarium inoculum is commonly found in most container and bareroot nurseries on healthy and diseased seedlings, in nursery soils, and on conifer seeds. Isolates of Fusarium spp. can differ in virulence; however, virulence and colony morphology are not correlated. Forty-one isolates of Fusarium spp., morphologically indistinguishable from F. oxysporum, were collected from nursery samples (soils, healthy seedlings, and diseased seedlings). These isolates were characterized by amplified fragment length polymorphism (AFLP) and DNA sequencing of nuclear rDNA (internal transcribed spacer including 5.8S rDNA), mitochon-drial rDNA (small subunit [mtSSU]), and nuclear translation elongation factor 1-alpha. Each isolate had a unique AFLP phenotype. Out of 121 loci, 111 (92%) were polymorphic; 30 alleles were unique to only highly virulent isolates and 33 alleles were unique to only isolates nonpathogenic on conifers. Maximum parsimony and Bayesian analyses of DNA sequences from all three regions and the combined data set showed that all highly virulent isolates clearly separated into a common clade that contained F. commune, which was recently distinguished from its sister taxon, F. oxysporum. Interestingly, all but one of the nonpathogenic isolates grouped into a common clade and were genetically similar to F. oxysporum. The AFLP cladograms had similar topologies when compared with the DNA-based phylograms. Although all tested isolates were morphologically indistinguishable from F. oxysporum based on currently available monographs, some morphological traits can be plastic and unreliable for identification of Fusarium spp. We consider the highly virulent isolates to be F. commune based on strong genetic evidence. To our knowledge, this is the first reported evidence that shows F. commune is a cause of Fusarium disease (root rot and dampingoff) on Douglas-fir seedlings. Furthermore, several AFLP genetic markers and mtSSU sequences offer potential for development of molecular markers that could be used to detect and distinguish isolates of F. oxysporum nonpathogenic to conifers and highly virulent isolates of F. commune in forest nurseries.


Plant Disease ◽  
2005 ◽  
Vol 89 (10) ◽  
pp. 1130-1130 ◽  
Author(s):  
S. T. Koike ◽  
T. R. Gordon

Cilantro, or coriander (Coriandrum sativum), is a leafy vegetable in the Apiaceae and is grown commercially in California primarily for use as a fresh herb. During 2002 and 2003 in coastal California (Santa Barbara County), commercial cilantro fields showed symptoms of a wilt disease. Affected plants grew poorly and were stunted. Lower foliage turned yellow with reddish tinges, and plants wilted during warmer times of the day. The main stem, crown, and taproot exhibited vascular discoloration that was reddish to light brown. As disease progressed, plants eventually died. For both years, the disease distribution was limited to isolated small patches (each patch measuring less than 1 m2 in area). A fungus was consistently isolated from symptomatic vascular tissue in crowns and taproots. On the basis of colony and conidial morphology, the isolates were identified as Fusarium oxysporum (2). No other fungi or bacteria were recovered from these plants. To test pathogenicity, suspensions containing 1 × 106 conidia/ml were prepared for five isolates. The roots of 30-day-old cilantro plants of four cultivars (30 plants each of Festival, Leisure, Santo, and LSO 14) were clipped and then soaked in the suspensions for 20 min. The roots of 30 plants of each cultivar were soaked in water as a control. Plants were repotted into new redwood bark + peat moss rooting medium and maintained in a greenhouse setting at 24 to 26°C. After 1 month, 95% or more of the inoculated plants showed yellowing and vascular discoloration symptoms similar to those seen in the field. F. oxysporum was reisolated from all inoculated plants. The four cilantro cultivars did not show differences in disease severity. Control plants showed no symptoms, and the fungus was not recovered from these plants. The experiment was repeated and the results were the same. Experiments also were conducted to determine if cilantro isolates could cause disease in celery (Apium graveolens var. dulce). Celery transplants and cilantro seedlings were prepared and inoculated as described above. However, after 2 months, celery plants did not show any disease symptoms, while the cilantro developed wilt symptoms and eventually died. A Fusarium wilt disease has been reported on coriander in Argentina and India where the pathogen was named F. oxysporum f. sp. coriandrii (1,3). To our knowledge, this is the first report of Fusarium wilt of cilantro in California. References: (1) M. Madia et al. Fitopatologia 34:155, 1999. (2) P. E. Nelson et al. Fusarium species: An Illustrated Manual for Identification. Pennsylvania State University Press, University Park, 1983. (3) U. S. Srivastava. Indian Phytopathol. 22:406, 1969.


1982 ◽  
Vol 54 (4) ◽  
pp. 225-244
Author(s):  
Mauritz Vestberg ◽  
Risto Tahvonen ◽  
Kyösti Raininko

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.


Plant Disease ◽  
2020 ◽  
Vol 104 (5) ◽  
pp. 1312-1317
Author(s):  
X. Lai ◽  
A. Qi ◽  
Y. Liu ◽  
L. E. Del Río Mendoza ◽  
Z. Liu ◽  
...  

Minnesota and North Dakota combined contain 55% of the sugar beet production area in the United States, contributing to 49% of the nation’s sugar beet production in 2018. Fusarium diseases caused by Fusarium oxysporum f. betae and F. secorum on sugar beet can cause significant reduction in both root yield and sucrose concentration and purity. The objective of this research was to identify an alternative artificial inoculation method to induce Fusarium diseases on sugar beet leaves and roots caused by both Fusarium spp. in greenhouse conditions to better aid in research efforts. We tested four inoculation methods, including barley to seed, barley to root, drenching, and cutting. and compared them with the conventional root-dipping inoculation method. The inoculation method of placing Fusarium-colonized barley seed close to sugar beet seed (barley to seed) caused levels of symptom severities on both leaves and roots similar to the root-dipping method. Because the traditional root-dipping method involves a laborious transplant process, use of infected barley seed as inoculum may serve as an alternative method in the evaluation of host resistance and pathogen virulence among Fusarium diseases by Fusarium spp. on sugar beet at the seed or seedling stage.


2022 ◽  
Vol 8 (1) ◽  
pp. 53
Author(s):  
Raman Thangavelu ◽  
Esack Edwinraj ◽  
Muthukathan Gopi ◽  
Periyasamy Pushpakanth ◽  
Kotteswaran Sharmila ◽  
...  

Fusarium wilt caused by Fusarium oxysporum f. sp. cubense (Foc), is the most lethal soil-borne fungal pathogen infecting bananas. Foc race 1 (R1) and 4 (R4) are the two most predominant races affecting the economically important Cavendish group of bananas in India. A total of seven vegetative compatibility groups (VCGs) from three pathogenic races were isolated during our field survey and were found to be highly virulent towards cv. Grande Naine. According to comparative genome analyses, these Indian Foc VCGs were diverse in genomic organization and effector gene profiles. As a result, false-positive results were obtained with currently available molecular markers. In this context, the study has been initiated to develop PCR-based molecular markers for the unambiguous identification of Indian Foc R1 and R4 isolates. Whole-genome sequences of Foc R1 (GCA_011316005.3), Foc TR4 (GCA_014282265.3), and Foc STR4 (GCA_016802205.1), as well as the reference genomes of Foc (ASM799451v1) and F. oxysporum f. sp. lycopersici (Fol; ASM14995v2), were aligned to identify unique variable regions among the Foc races. Using putative chromosome and predicted gene comparison, race-specific unique Foc virulence genes were identified. The putative lineage-specific identified genes encoding products secreted in xylem (SIX) that may be necessary for disease development in the banana. An in silico analysis was performed and primers were designed from a region where sequences were dissimilar with other races to develop a specific marker for Foc R1, R4, TR4, and STR4. These race-specific markers allowed target amplification in the characterized highly virulent Foc isolates, and did not show any cross-amplification to any other Foc races, VCGs or banana pathogens, Fusarium species, and non-pathogenic Fusarium oxysporum isolates. The study demonstrated that the molecular markers developed for all the three Foc races of India could detect the pathogen in planta and up to 0.025 pg µL−1 DNA levels. Thus, the markers developed in this study are novel and could potentially be useful for the accurate diagnosis and detection of the Indian Foc races which are important for the effective management of the disease.


Plant Disease ◽  
2006 ◽  
Vol 90 (12) ◽  
pp. 1554-1554 ◽  
Author(s):  
L. E. Hanson

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.


Plant Disease ◽  
2019 ◽  
Vol 103 (8) ◽  
pp. 2070-2075 ◽  
Author(s):  
Glen L. Hartman ◽  
Susan P. McCormick ◽  
Kerry O’Donnell

Numerous pathogen surveys have reported that diverse Fusarium spp. threaten soybean production in North and South America. However, little research has been conducted to characterize Fusarium pathogens of soybean in sub-Saharan Africa. Our objectives were to (i) identify Fusarium spp. isolated from discolored root segments of soybean grown in Ethiopia and Ghana using DNA sequence data, (ii) determine whether isolates nested in the Fusarium incarnatum-equiseti and F. sambucinum species complexes (FIESC and FSAMSC, respectively) produced trichothecene mycotoxins in vitro, and (iii) test these isolates for pathogenicity on soybean. Molecular phylogenetic analyses revealed that the trichothecene mycotoxin-producing isolates comprised three undescribed species within the FIESC and FSAMSC. Mycotoxin type B trichothecene 4,15-diacetylnivalenol or T-2 toxin and related type A neosolaniol trichothecenes were produced by 18 of the 21 isolates. Of the 12 isolates from Ethiopia and Ghana tested for their impact on seed germination, 5, comprising two undescribed phylospecies (i.e., Fusarium sp. number 3 and Fusarium sp. FIESC 2,) completely inhibited germination, whereas 4 caused no reduction in germination. Root lesions induced by all 12 isolates were greater than the uninoculated negative control. Additional variation among the isolates was reflected in differences (α = 0.05) in lesion lengths, which ranged from 34 to 67% of total root length. This is the first report characterizing FIESC and FSAMSC isolates from soybean roots in Ethiopia and Ghana.


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