scholarly journals Virulence of Fusarium species to alfalfa seedlings

2005 ◽  
pp. 167-171
Author(s):  
Vesna Krnjaja ◽  
Jelena Levic ◽  
M. Ivanovic ◽  
Zorica Tomic

In in vitro conditions, virulence of 91 isolates of species Fusarium genus (F. oxysporum, F. solani, F. acuminatum, F. equiseti, F. arthrosporioides, F. prolifera- tum, F. avenaceum, F. semitectum, F. tricinctum, F. sporotrichioides and F. graminearum) towards alfalfa seedlings was investigated. Isolates of investigated species originated from diseased alfalfa plants collected at four locations in Serbia based on symptoms of wilting caused by Fusarium and root rotting. Pathogenicity and virulence of investigated isolates of Fusarium spp. were determined by visual evaluation of inoculated seedlings of cultivar K28 in laboratory conditions. All isolated of investigated species had pathogenic effect on alfalfa seedlings which expressed symptoms such as necrosis of root, moist rotting and "melting of seedlings". Colour of necrotic root tissue varied from light brown, brown lipstick red to explicit black, depending on the Fusarium species. Strong virulence was established in 48 isolates, medium virulence in 31 and weak virulence in 12 isolates.

Author(s):  
Vesna Krnjaja ◽  
Jelena Levic ◽  
Mirko Ivanovic ◽  
Zorica Tomic

In in vitro conditions, virulence of 91 isolates of species Fusarium genus (F. oxysporum, F. solani, F. acuminatum, F. equiseti, F. arthrosporioides, F. proliferatum, F. avenaceum, F. semitectum, F. tricinctum, F. sporotrichioides and F. graminearum) towards alfalfa seedlings was investigated. Isolates of investigated species originated from diseased alfalfa plants collected on four locations in Serbia based on symptoms of wilting caused by fusarium and root rotting. Pathogenicity and virulence of investigated isolates of Fusarium spp. were determined by visual evaluation of inoculated seedlings of cultivars K28 in laboratory conditions. All isolated of investigated species had pathogenic effect on alfalfa seedlings, which expressed symptoms such as necrosis of root, moist rotting and "melting of seedlings". Colour of necrotic root tissue varied from light brown, brown, lipstick red to explicit black, depending on the Fusarium species. Strong virulence was established in 48 isolates, medium virulence in 31 and weak virulence in 12 isolates.


Toxins ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 438
Author(s):  
Mary E. Ridout ◽  
Bruce Godfrey ◽  
George Newcombe

Fusarium species coexist as toxigenic, systemic pathogens in sweet corn seed production in southwestern Idaho, USA. We hypothesized that fungal antagonists of seedborne Fusarium would differentially alter production of Fusarium mycotoxins directly and/or systemically. We challenged the Fusarium complex by in vitro antagonism trials and in situ silk and seed inoculations with fungal antagonists. Fungal antagonists reduced growth and sporulation of Fusarium species in vitro from 40.5% to as much as 100%. Pichia membranifaciens and Penicillium griseolum reduced fumonisin production by F. verticillioides by 73% and 49%, respectively, while P. membranifaciens and a novel Penicillium sp. (WPT) reduced fumonisins by F. proliferatum 56% and 78%, respectively. In situ, pre-planting inoculation of seeds with Penicillium WPT systemically increased fumonisins in the resulting crop. Morchella snyderi applied to silks of an F1 cross systemically reduced deoxynivalenol by 47% in mature seeds of the F2. Antagonists failed to suppress Fusarium in mature kernels following silk inoculations, although the ratio of F. verticillioides to total Fusarium double with some inoculants. Fusarium mycotoxin concentrations in sweet corn seed change systemically, as well as locally, in response to the presence of fungal antagonists, although in Fusarium presence in situ was not changed.


Biology ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 69
Author(s):  
Ben Kalman ◽  
Dekel Abraham ◽  
Shaul Graph ◽  
Rafael Perl-Treves ◽  
Yael Meller Harel ◽  
...  

Over the past decade, there have been accumulating reports from farmers and field extension personnel on the increasing incidence and spread of onion (Allium cepa) bulb basal rot in northern Israel. The disease is caused mainly by Fusarium species. Rotting onion bulbs were sampled from fields in the Golan Heights in northeastern Israel during the summers of 2017 and 2018. Tissue from the sampled onion bulbs was used for the isolation and identification of the infecting fungal species using colony and microscopic morphology characterization. Final confirmation of the pathogens was performed with PCR amplification and sequencing using fungi-specific and Fusarium species-specific primers. Four Fusarium spp. isolates were identified in onion bulbs samples collected from the contaminated field: F. proliferatum, F. oxysporum f. sp. cepae, and two species less familiar as causative agents of this disease, F. acutatum and F. anthophilium. Phylogenetic analysis revealed that these species subdivided into two populations, a northern group isolated from white (Riverside cv.) onion bulbs, and a southern group isolated from red (565/505 cv.) bulbs. Pathogenicity tests conducted with seedlings and bulbs under moist conditions proved that all species could cause the disease symptoms, but with different degrees of virulence. Inoculating seeds with spore suspensions of the four species, in vitro, significantly reduced seedlings’ germination rate, hypocotyl elongation, and fresh biomass. Mature onion bulbs infected with the fungal isolates produced typical rot symptoms 14 days post-inoculation, and the fungus from each infected bulb was re-isolated and identified to satisfy Koch’s postulates. The onion bulb assay also reflected the degree of sensitivity of different onion cultivars to the disease. This work is the first confirmed report of the direct and primary cause of Fusarium onion basal rot disease in northeastern Israel. These findings are a necessary step towards uncovering the mycoflora of the diseased onion plants and developing a preventive program that would reduce the disease damage.


2021 ◽  
Vol 5 (2) ◽  
pp. 57
Author(s):  
Gabriel Ginane Barreto ◽  
Ana Carla da Silva Santos ◽  
Mirelly Miguel Porcino ◽  
Patrick Materatski ◽  
Carla Varanda ◽  
...  

Biological control strategies have become an important tool in the sustainable management of plant diseases. This paper aims to report the Fusarium species that affect fava beans (Phaseolus lunatus L.) grown in Paraíba, Brazil, and determines the potential of Trichoderma isolates to control these fungi. Two Trichoderma and ten Fusarium isolates from fava bean seeds were selected. The beans were obtained from cultivated areas in the municipalities of Remígio, Alagoa Grande and Campina Grande, in Paraíba state. Phylogenetic analyzes based on DNA sequences of the translation elongation factor 1-α (TEF1) gene resolved the Fusarium isolates into four species belonging to the F. fujikuroi and F. incarnatum-equiseti species complexes. In vitro tests showed that the two isolates of Trichoderma tested presented antagonistic potential against the pathogens from the fava beans evaluated. In the direct comparison test, the growth of the pathogens was reduced from the seventh day in both treatments. Sporulation also showed a reduction, but only for 40% of Fusarium isolates. This work demonstrates that Trichoderma isolates can be used as a sustainable alternative to manage Fusarium spp. infection of fava beans.


2010 ◽  
Vol 46 (No. 2) ◽  
pp. 59-65 ◽  
Author(s):  
K. Hudec ◽  
D. Muchová

The influence of temperature and species origin on the in vitro growth rate and pathogenicity of Fusarium and Microdochium nivale (F. avenaceum, F. culmorum, F. graminearum, F. poae, and M. nivale) to wheat seedlings was examined. The mycelial growth of Fusarium avenaceum, F. culmorum, F. graminearum, and F. poae was the fastest at 25°C, and of M. nivale at 15°C. The isolates of F. culmorum, F. graminearum and F. poae originating from mountain regions grew significantly faster at 15°C than those from flatland regions. The isolates from flatland regions grew significantly faster at 25°C than those from mountain regions. F. culmorum and F. graminearum were the most pathogenic species to the root development. The retardation of wheat grain germination caused by the tested species was assessed in descending order: F. culmorum, F. graminearum, M. nivale, F. avenaceum, F. poae. The biomass growth retardation at 15°C was assessed in descending order: F. culmorum, F. graminearum, M. nivale, F. avenaceum, F. poae; at 25°C as follows: F. graminearum, F. culmorum, F. avenaceum, M. nivale, F. poae. The isolates of M. nivale and F. poae originating from mountain regions were significantly more pathogenic than those from flatland regions. The results suggest that there exist different temperature ecotypes and pathotypes of Fusarium species and Microdochium nivale across the territory of the Slovak Republic.


Biologia ◽  
2008 ◽  
Vol 63 (3) ◽  
Author(s):  
Antónia Šrobárová ◽  
Svetlana Šliková ◽  
Valéria Šudyova

AbstractSpecies associated with Fusarium head blight are depending on the production and edaphic conditions. The differences are found in the representation of various Fusarium spp. in the diseases, which sporadically occur all over the territory of Slovakia, in all agricultural production types. We identified fifteen Fusarium species during ten years of investigation. Most of the mentioned species F. culmorum (W.G. Smith) Sacc., F. graminearum Schwabe, recently F. cerealis (Cooke) Sacc. (crookwellense Burgess, Nelson & Tousson) and F. sambucinum Fuckel in diseased caryopsis are seed transmitted. The significant differences among species and intra species in cultural and pathogenicity assays in vitro and in vivo were correlated. Some of them are able to produce toxic metabolites — deoxynivalenone, which probably play a role in the aggressiveness of the pathogen and promote disease development and pathogen colonization.


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.


2021 ◽  
Author(s):  
Mohamed Hafez ◽  
Ryan Gourlie ◽  
Melissa Telfer ◽  
Nicola Schatz ◽  
Kelly Turkington ◽  
...  

Fusarium head blight (FHB) and Fusarium crown and root rot (FCRR) are major wheat diseases worldwide. In this study, wheat node and grain samples were collected from four representative sites across the western Canadian prairies in 2018 growing season to characterize the major Fusarium spp. and other mycobiota associated with wheat in these regions. In total, 994 fungal isolates were recovered and based on culture and molecular diagnostic methods, three genera constituted over 90% of all fungal isolates, these were Alternaria (39.6%), Fusarium (27.8%), and Parastagonospora (23.9%). A qPCR was developed to quantify the most frequently isolated Fusarium spp. in infected wheat tissues: F. avenaceum, F. culmorum, F. graminearum and F. poae. The qPCR specificity was validated in silico, in vitro and in planta and proved specific to the target species.. The qPCR results showed that F. graminearum was not detected frequently in the four tested locations in this study. F. poae was the most abundant Fusarium species in grain samples in all tested locations. However, in node samples, F. culmorum (Beaverlodge and Scott) and F. avenaceum (Lacombe and Lethbridge) were the most abundant species. Trichothecene genotyping, showed that the 3ADON is the most dominant trichothecene genotype (68%), followed by type-A trichothecenes (29.5%), while the 15ADON trichothecene genotype was least dominant (2.5%) and the NIV genotype was not detected. Moreover, a total of 129 TEF1α sequences from nine Fusarium spp. were compared at haplotype level to evaluate genetic variability and haplotype distribution. F. avenaceum and F.poae exhibited higher diversity.


2015 ◽  
Vol 30 (2) ◽  
pp. 99-105 ◽  
Author(s):  
Sonja Tancic ◽  
Slavica Stankovic ◽  
Jelena Levic ◽  
Vesna Krnjaja

A total of 39 Fusarium graminearum, F. sporotrichioides, F. semitectum and F. equiseti isolates, originating from wheat and maize samples collected at 10 locations in Serbia, were analyzed by ELISA method for their potential of deoxynivalenol (DON) and zearalenone (ZEA) production under optimal laboratory conditions. Fusarium graminearum isolates with the highest intraspecies variability were the best producers of both deoxynivalenol and zearalenone. In contrast, F. equiseti isolates were the weakest producers of these two toxins. Considering the plant origin of the isolates, wheat-originating F. sporotrichioides isolates were better deoxynivalenol producers, while the maize-originating isolates produced more zearalenone. There was no clear difference in ZEA production between wheat- and maizeoriginating isolates of F. graminearum, while higher average DON concentrations were produced by F. graminearum wheat-originating isolates. Negative correlation was detected between the production of deoxynivalenol and zearalenone by various Fusarium spp.


2017 ◽  
Vol 6 (5) ◽  
pp. 186-193
Author(s):  
Vipin Panwar ◽  
Ashok Aggarwal ◽  
Surinder Paul ◽  
Virender Singh ◽  
Pankaj K. Singh ◽  
...  

Fusarium head blight (FHB) or head scab is emerging as a destructive disease affecting the quantity and quality of wheat worldwide. Several Fusarium spe-cies have been associated with the disease but their composition varies among geographical regions and years. Climatic factors like temperature, pH and humidity influence the growth, survival and infestation of Fusarium species. In the present study, response of thirty six isolates of three Fusarium spp. viz F. graminearum, F. oxysporum and F. pallidoroseum (F. semitectum) to different temperature and pH was assessed by analysing their in vitro growth rate (mm/day) on potato dextrose agar (PDA) medium. We found that all the isolates responded differentially but interestingly isolates of F. graminearum showed better tolerance at broader range of temperature and pH. This attributes make F. graminearum a widely distributed and potent pathogen of wheat.


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