scholarly journals The occurrence of Fusarium spp. on oat (Avena sativa L.) and susceptibility of seedlings of selected genotypes to infection with Fusarium graminearum Schwabe

2014 ◽  
Vol 67 (2) ◽  
pp. 57-66 ◽  
Author(s):  
Irena Kiecana ◽  
Elżbieta Mielniczuk ◽  
Małgorzata Cegiełko ◽  
Alina Pastucha

<p>The present study was carried out in the years 2010–2012 in the fields of the Strzelce Plant Breeding Company Ltd., belonging to the Plant Breeding and Acclimatization Institute in Radzików, and it included 39 oat genotypes. At the six-week seedling stage, the percentage of plants with root and leaf sheath necrosis symptoms was evaluated. In 2010 the percentage of seedlings with disease symptoms ranged from 6.5% to 25%, in 2011 it ranged from 17% to 34.5%, whereas in 2012 from 10% to 25%. In 2010 the disease index ranged from 1.4 to 5.7, in 2011 from 4.5 to 8.8, while in 2012 it was between 2.0 and 5.4.</p><p>Mycological analysis showed that large numbers of <em>Fusarium </em>spp. colonies were obtained both from the roots and leaf sheaths. Isolates of these fungi accounted for 63.48% of the total fungi isolated from seedlings. Seedlings grown under the conditions of central Poland were damaged by the species <em>F. culmorum</em>, <em>F. avenaceum, </em>and <em>F. solani</em>. The investigation of the susceptibility of 15 oat genotypes to infection with two <em>Fusarium graminearum </em>strains – Tz 56 and Tk 235 – was carried out under growth chamber conditions at a temperature of 22–23°C and relative air humidity of 85%. The <em>F. graminearum </em>strain Tz 56 proved to be the most pathogenic to seedlings of the breeding lines STH 0.9403 and POB 1316/08, for which the disease index was 80.5 and 75.5, respectively. The lowest pathogenicity of the a.m. strain was recorded in the case of the genotype DC 1832/05, for which the disease index was 26.5. The <em>F. graminearum </em>strain Tk 235 proved to be the most pathogenic to the genotypes STH 0.9403 and STH 0.9423, for which the disease index was 70.5 and 70.0, respectively, whereas this strain was least pathogenic to the breeding line DC 2112/05, in the case of which the disease index was 25.5.</p>

2019 ◽  
Vol 18 (2) ◽  
Author(s):  
Elżbieta Mielniczuk ◽  
Małgorzata Cegiełko

In Poland, cultivars belonging to three species of Tagetes are grown: T. erecta, T. patula, T. tenuifolia. Presented studies were conducted in 2015 in two localities of the Lublin region. Those studies included cultivars of Tagetes spp.: T. erecta (cv. ‘Alaska’, ‘Hawaii’, ‘Mann Im Mond’), T. patula (cv. ‘Bolero’ and ‘Carmen’) and T. tenuifolia (cv. ‘Lemon Gem’ and ‘Lulu’). Six weeks after the sowing and in flowering stage of analyzed marigold cultivars, the plants healthiness was assessed. The mean values of the disease index ranged from 16.25 to 29.0. The main cause of root infection at the seedling stage proved to be the species of Fusarium and Rhizoctonia solani. Proportion of plants with disease symptoms in flowering stage ranged from 1.25 to 5.5%. Regardless of the place of cultivation, species: A. alternata, F. culmorum and F. equiseti were the most often isolated from diseased plants in the flowering stage. Studies on the susceptibility of analyzed cultivars of marigold to infection by Fusarium culmorum, F. equiseti and F. sporotrichioides were conducted in a growth chamber. Significantly, the lowest value of the disease index of cultivar ‘Bolero’ (T. patula) allows to accept that cultivar as the least susceptible to infestation by Fusarium spp. under conditions of controlled temperature and humidity


2014 ◽  
Vol 40 (2) ◽  
pp. 156-162 ◽  
Author(s):  
Antonio Eduardo Loureiro da Silva ◽  
Erlei Melo Reis ◽  
Rosane Fátima Baldiga Tonin ◽  
Anderson Luiz Durante Danelli ◽  
Aveline Avozani

O trabalho teve como objetivos, identificar e quantificar os fungos associados a sementes de azevém, comparar a incidência em diferentes meios de cultura, e determinar o número de escleródios de Claviceps purpurea presentes em amostras de sementes. Foram analisadas 37 amostras de sementes de azevém provenientes de municípios do Rio Grande do Sul, Santa Catarina e Paraná. As sementes foram plaqueadas em três meios de cultura: BDA, semi-seletivo de Reis e semi-seletivo de Segalin & Reis, analisando-se a incidência dos fungos. Para detecção de C. purpurea, foram pesados 100g de sementes por amostra e, através de exame visual, foi determinado o número de escleródios. Os fungos detectados foram Alternaria alternata, Bipolaris sorokiniana, Drechslera spp., D. siccans, Fusarium graminearum, Fusarium spp., Aspergillus spp. e Penicillium sp. A incidência de A. alternata variou de 0,0% a 33,7% e freqüência de 89,2% nas amostras analisadas. Para B. sorokiniana a incidência foi de 0,0% a 2,2% e frequência de 62,2%, Drechslera spp., apresentou incidência de 0,0% a 40,3% e frequência de 78,4%. D. siccans a incidência foi de 0,1% a 20,0% e frequência de 100%.Para Fusarium spp., e F. graminearum a incidência foi de 0,0% a 31,0% e 0,0% a 11,3% e frequência de 81,1% e 64,9%, de 0,0% a 43,7% de incidência e 94,6% de frequência para Aspergillus spp. e Penicillium sp. com incidência entre 0,0% a 51,7% e frequência de 91,9%, respectivamente. O fungo C. purpurea foi encontrado em 81,1% das amostras em estudo.


2008 ◽  
Vol 8 (2) ◽  
pp. 217-229 ◽  
Author(s):  
Vellaisamy Ramamoorthy ◽  
Edgar B. Cahoon ◽  
Mercy Thokala ◽  
Jagdeep Kaur ◽  
Jia Li ◽  
...  

ABSTRACT The C-9-methylated glucosylceramides (GlcCers) are sphingolipids unique to fungi. They play important roles in fungal growth and pathogenesis, and they act as receptors for some antifungal plant defensins. We have identified two genes, FgMT1 and FgMT2, that each encode a putative sphingolipid C-9 methyltransferase (C-9-MT) in the fungal pathogen Fusarium graminearum and complement a Pichia pastoris C-9-MT-null mutant. The ΔFgmt1 mutant produced C-9-methylated GlcCer like the wild-type strain, PH-1, whereas the ΔFgmt2 mutant produced 65 to 75% nonmethylated and 25 to 35% methylated GlcCer. No ΔFgmt1ΔFgmt2 double-knockout mutant producing only nonmethylated GlcCer could be recovered, suggesting that perhaps C-9-MTs are essential in this pathogen. This is in contrast to the nonessential nature of this enzyme in the unicellular fungus P. pastoris. The ΔFgmt2 mutant exhibited severe growth defects and produced abnormal conidia, while the ΔFgmt1 mutant grew like the wild-type strain, PH-1, under the conditions tested. The ΔFgmt2 mutant also exhibited drastically reduced disease symptoms in wheat and much-delayed disease symptoms in Arabidopsis thaliana. Surprisingly, the ΔFgmt2 mutant was less virulent on different host plants tested than the previously characterized ΔFggcs1 mutant, which lacks GlcCer synthase activity and produces no GlcCer at all. Moreover, the ΔFgmt1 and ΔFgmt2 mutants, as well as the P. pastoris strain in which the C-9-MT gene was deleted, retained sensitivity to the antifungal plant defensins MsDef1 and RsAFP2, indicating that the C-9 methyl group is not a critical structural feature of the GlcCer receptor required for the antifungal action of plant defensins.


Author(s):  
Shehu I. B. ◽  
Kharall A. ◽  
Makinta B.

The experiment was conducted in the pathology of department of crop protection univesity of Maiduguri Borno state. Which is located at latitude 11051N and longitude 13015E to exermine or to isolate and identified the fungi pathogen responsible for damaging same tomatoes cultivars (Solanum lycopersicon) seed in maiduguri Borno state.The result show that the improve variety of tomatoes seed has number of fungal isolation in the sample where the fungal include Aspergillus niger, fusarium spp, penecillium spp .Whereby in the cullum, the Aspergillus were present. Just less in the following treatment T1(Rio grand), T2(Tema), T3(Uc-82B) Compared to that of fungal pathogen isolate in the local sample which are present T1(Seria dan zang), T2(Dan gashua), T3(Roman dan mazar), T4(Dan jino). Whereas in the Fusarium spp in the improved variety sample the fungal are present in T1(Rio grand), T2(Tema), T3(Uc -82B), and T5(Roa savannah) while in local variety sample the fungal pathogen are present in T1(Seria dan zang), T3(Roman dan mazar), T4(Dan jino) and T5(Utc) where in penilluim spp the fungal are present in the improve variety in T1(Rio grand), T2(Tema), T3(Uc-82B), and T5(Roma savannah) compared to that of the local variety sample which are in T2(Dan gashua), T3(Roman dan mazar) and T5(Utc) (Table1).Whereas in the mean disease index recorded on improved cultivars tomatoes. The result shows that T1with (98.14%) are recorded the highest index followed by T2(Tema) with (93.10%) while the least was recorded on T4(Roma vf) with (46.21%). (Table2) compared to that of local variety sample where by the highest disease index was recorded in T3(Roman dan mazar) with (100%) and the least was recorded on T1(Seria dan zang) with (97.23) and the least was recorded T4(Dan jino) with (92.26)(Table3).


Plant Disease ◽  
2001 ◽  
Vol 85 (2) ◽  
pp. 231-231
Author(s):  
P. F. Colbaugh ◽  
W. A. Mackay ◽  
T. D. Davis

Lupinus havardii Wats., commonly known as Big Bend or Chisos bluebonnet, is a showy winter annual that can reach 1.0 to 1.5 m in height and produces blue, fragrant inflorescence (racemes). L. havardii is native to a narrow geographic range along the Mexican border in southwest Texas. The inflorescence of L. havardii has considerable potential in the cut flower industry where there is a need for high-quality, durable flowers with a blue color (1). Several crops have been produced in the greenhouse to determine production and post-harvest characteristics of the cut inflorescence. Under greenhouse growing conditions during March through June 1999, numerous plants of L. havardii cv. Texas Sapphire grown in raised beds and in containers in both Dallas and El Paso, TX, were observed with blighted flower racemes with light brown to gray lesions ranging from 1 to 5 cm in length. The racemes were attacked at varying ages and eventually assumed a hooked appearance where the terminal 15 cm of the raceme was bent downward. Isolations from symptomatic lesions removed from L. havardii flower stalks consistently yielded cultures of an Alternaria sp. on potato-dextrose agar. Typical conidia measured 27 μm length and 11 μm width with 3 to 5 transverse septa. The fungus was identified as A. alternata (Fries) Keissler consistent with the description in Ellis (2). Pathogenicity tests were conducted in the laboratory by inoculating cut inflorescences with agar disks containing the fungus. Inoculations produced light brown lesions on the racemes that were typical of disease symptoms observed on greenhouse crops. In addition to the blue-flowered Texas Sapphire cultivar, we also observed the disease symptoms on pink and white flowered breeding lines of L. havardii. This disease is important as a flower stem blighting pathogen and could severely restrict production of cut flowers during the growing season. This is the first report of Alternaria sp. attacking L. havardii. References: (1) T. D. Davis. HortScience 29:1110, 1994. (2) M. B. Ellis. 1971. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute Kew, England.


1969 ◽  
Vol 69 (1) ◽  
pp. 57-61
Author(s):  
S. D. Rodríguez ◽  
R. Rodríguez ◽  
P. L. Meléndez

The reaction of eight species of citrus and the chironja hybrid to inoculations with S. tumefaciens was evaluated in the greenhouse. All hosts developed disease symptoms, but their responses varied. Rough lemon was the host most severely affected by this pathogen, showing dieback symptoms 60 days after inoculation. The lowest disease index was observed in sour orange.


Author(s):  
Rozalia KADAR ◽  
Amin Said SARDAR Amin Said SARDAR

Fusarium  Head Blight (FHB), caused by Fusarium spp., has become one of the most destructive diseases in the world’s wheat growing areas, especially in humid and semihumid regions. More precise data relating the effects of FHB on yield have been obtained using inoculated trials. The situation is totally changed by inoculation with Fusarium. Because this disease affected wheat in flowering stage, number of grain/spike is strongly diminished. It can be observed the behavior of Turda 95 and Dumbrava varieties created at ARDS Turda which lose less number of grain than other cultivars.


Plant Disease ◽  
2000 ◽  
Vol 84 (9) ◽  
pp. 980-988 ◽  
Author(s):  
B. Wang ◽  
S. N. Jeffers

A previously unreported disease was observed on 11 cultivars of container-grown hosta plants at five wholesale nurseries in South Carolina between 1997 and 1999. Symptoms included leaf yellowing, plant stunting, rotting of and vascular discoloration in roots, and necrosis in the crowns. Fusarium spp. consistently were isolated from symptomatic hosta plants. Four species were recovered: F. solani, F. oxysporum, F. proliferatum, and an undescribed species designated Fusarium sp.; F. solani and Fusarium sp. were recovered most frequently. To demonstrate pathogenicity, four methods were used to inoculate hosta plants with representative isolates of F. solani, F. oxysporum, and Fusarium sp. Two types of inoculum, colonized oat seeds and conidium suspensions, were used to inoculate wounded and nonwounded plants. Disease symptoms occurred consistently only on hosta plants inoculated by dipping wounded roots and crowns into suspensions of conidia. Symptoms were most severe on plants inoculated with Fusarium sp. and much less severe on plants inoculated with F. solani or F. oxysporum. Disease severity increased and fresh weight of inoculated plants decreased when the concentration of inoculum of Fusarium sp. was increased over the range of 1 × 103 to 1 × 107 conidia per ml. Isolates of Fusarium sp., F. solani, and F. oxysporum varied in virulence when Hosta ‘Francee’ plants were inoculated. This study demonstrated that Fusarium root and crown rot of container-grown hostas is caused primarily by Fusarium sp. but that it also can be caused by F. solani and F. oxysporum. Fusarium sp. appears to be taxonomically distinct from other species, and its identity currently is under investigation.


Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 943 ◽  
Author(s):  
Beata Toth ◽  
Andrea Gyorgy ◽  
Monika Varga ◽  
Akos Mesterhazy

In previous research, conidium concentrations varying between 10,000 and 1,000,000/mL have not been related to any aggressiveness test. Therefore, two Fusarium graminearum and two Fusarium culmorum isolates were tested in the field on seven genotypes highly differing in resistance at no dilution, and 1:1, 1:2, 1:4, 1:8, and 1:16 dilutions in two years (2013 and 2014). The isolates showed different aggressiveness, which changed significantly at different dilution rates for disease index (DI), Fusarium-damaged kernels (FDK), and deoxynivalenol (DON). The traits also had diverging responses to the infection. The effect of the dilution could not be forecasted. The genotype ranks also varied. Dilution seldomly increased aggressiveness, but often lower aggressiveness occurred at high variation. The maximum and minimum values varied between 15% and 40% for traits and dilutions. The reductions between the non-diluted and diluted values (total means) for DI ranged from 6% and 33%, for FDK 8.3–37.7%, and for DON 5.8–44.8%. The most sensitive and most important trait was DON. The introduction of the aggressiveness test provides improved regulation compared to the uncontrolled manipulation of the conidium concentration. The use of more isolates significantly increases the credibility of phenotyping in genetic and cultivar registration studies.


2013 ◽  
Vol 41 (1) ◽  
pp. 184
Author(s):  
Oktay EROÄžAN ◽  
Emine KARADEMIR ◽  
Çetin KARADEMIR ◽  
Aydın UNAY

The susceptibility of cotton genotypes obtained from F6 and F7 generations to Verticillium wilt (VW) disease (Verticillium dahliae Kleb.), was studied under artificial and natural infestation during 2009 and 2010 growing seasons at the Cotton Research Institute’s, Nazilli, Aydın, Turkey. In this study, fifteen cotton breeding lines and two control varieties were used as plant material. During the cotton growing season, foliar disease index (FDI), vascular disease index (VDI) and pot disease index (PDI) were observed in addition to seed cotton yield and some fiber quality characteristics. According to the obtained results, disease severity (DS) values observed in pot experiments were higher than field trials. In terms of DS, ‘Tamcot CD3H’ × ‘Tamcot Luxor-III’, ‘Maraş92’ × ‘Tamcot Sphinx’ and ‘Sayar 314’ × ‘Stoneville 453-I’ breeding lines exhibited similar values with tolerant ‘Carmen’ variety. ‘Tamcot CD3H’ × ‘Tamcot Sphinx’, ‘Sayar 314’ × ‘Stoneville 453-I’, ‘Sayar 314’ × ‘Stoneville 453-II’ and ‘Stoneville 453’ × ‘Tamcot Sphinx’ breeding lines which gave similar DS values with tolerant ‘Carmen’ variety were statistically on the same group with ‘Carmen’ variety suitable to seed cotton yield. In this study, the disease tolerant breeding lines had higher fiber strength values than susceptible lines, the lowest fiber strength value obtained from ‘Cukurova 1518’ susceptible variety.


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