scholarly journals First Report of Aloe Root and Stem Rot in China Caused by Fusarium solani

Plant Disease ◽  
2007 ◽  
Vol 91 (6) ◽  
pp. 768-768
Author(s):  
G. Ji ◽  
L. Wei ◽  
Y. He ◽  
Y. Wu
Keyword(s):  
Fusarium Solani ◽  
Yunnan Province ◽  
Fusarium Species ◽  
Stem Rot ◽  
Blue Pigment ◽  
Basal Cells ◽  
Aloe Barbadensis ◽  
Tissue Samples ◽  
First Report ◽  
Root Rots

During the springs of 2003 and 2004, a serious outbreak of root and stem disease occurred on Aloe barbadensis L. grown in commercial fields in Yuanjiang, Yunnan Province, Southwest China. The disease began with brown root rots that advanced to collars and stems, followed by internal decay of the lower stem. Diseased tissue samples collected from plants in different fields were surface disinfested and plated on potato dextrose agar (PDA). A Fusarium species was consistently isolated, and pure cultures were established by initiating new cultures with single spores. Grayish white and fluffy mycelium with a deep violet-blue pigment developed on PDA agar, with a growth rate of 3.4 cm in 3 days, and a dark, blue-green mass of confluent sporodochia or pionnotes covering the central part of the culture. Microconidia in false heads on long phialides were abundant when initially isolated but were infrequent in later cultures. Microconidia were generally single celled, oval to kidney shaped, and 8 to 16 × 2.5 to 4 μm. Macroconidia were abundant, cylindrical, slightly curved with blunt and rounded apical cells, and foot-shaped or notched basal cells, and mostly three to four septate, 27 to 50 × 3.6 to 5.7 μm. Chlamydospores were sparse, single or in short chains, thick walled, and 7 to 10 μm in diameter. This description corresponds to Fusarium solani (Mart.) Appel & Wollenw. emend. Snyd. & Hans as described by Nelson et al. (1). Inoculations with F. solani were made by dipping healthy aloe roots into a 300-ml suspension of 3 × 105 conidia/ml. Control plants were dipped in sterile water. All plants were potted in soil and kept in a greenhouse (2). After 30 days, all inoculated plants developed root rots followed by collar and stem rots that were similar to those observed in the field. Cultures of F. solani were reisolated from the diseased plants and identification was confirmed by conidial characteristics. No symptoms were observed on the control plants. Tests were repeated with similar results. In China, the Yunnan Province produces one-third of all aloe grown and this disease has a major impact on production. Aloe is grown in certified organic fields and chemical pesticides are not used. To our knowledge, this is the first report of F. solani causing root and stem rot of A. barbadensis. References: (1) P. E. Nelson et al. Fusarium Species: An Illustrated Manual for Identification. Pennsylvania State University Press, University Park, PA, 1983. (2) X. Ruan et al. Pages 211–215 in: Phytopathology Laboratory of Yunnan Province. Vol. 2. Y. Y. Shengfu, ed. Yunnan Science and Technology Press, Kunming, Yunnan, China, 1998.

scholarly journals First report of Fusarium solani causing stem rot of Dracaena in Iran

2016 ◽  
Vol 56 (1) ◽  
pp. 100-103 ◽  
Author(s):  
Mostafa Abedi-Tizaki ◽  
Doustmorad Zafari ◽  
Jamal Sadeghi
Keyword(s):  
Fusarium Solani ◽  
Elongation Factor ◽  
Stem Rot ◽  
Pathogenicity Test ◽  
Translation Elongation Factor ◽  
Translation Elongation ◽  
First Report ◽  
Brown Discoloration ◽  
Elongation Factor 1 Alpha ◽  
Elongation Factor 1

Abstract In July 2013, symptoms of stem rot were observed in the Dracaena sanderiana cuttings in greenhouses of Mahallat County, Markazi Province, Iran. The symptoms first appeared as severe wilting. Later, leaves became brown and necrotic. Symptoms on the cuttings were observed as rotted areas on the middle of the stems. The cortical tissues of the plants showed a distinct brown discoloration. Eventually, the infected plants died. The pathogen was isolated from Dracaena stems and identified as F. solani by a fragment of the translation elongation factor 1-alpha (EF-1α) gene. Fusarium solani was confirmed by a pathogenicity test, and the causal agent was re-isolated from infected D. sanderiana plants. To the best of our knowledge, this is the first report of stem rot caused by F. solani on the cuttings of D. sanderiana.

scholarly journals First Report of Fusarium Stem and Crown Rot of Fennel in Arizona Caused by Fusarium avenaceum

Plant Disease ◽  
2012 ◽  
Vol 96 (1) ◽  
pp. 145-145 ◽  
Author(s):  
S. T. Koike ◽  
T. R. Gordon ◽  
S. C. Kirkpatrick
Keyword(s):  
Base Pair ◽  
Fusarium Species ◽  
Elongation Factor ◽  
Crown Rot ◽  
Fusarium Avenaceum ◽  
Basal Cells ◽  
Foeniculum Vulgare ◽  
Eustoma Grandiflorum ◽  
First Report ◽  
Agar Plug

In 2010 in Yuma, AZ, field-grown fennel (Foeniculum vulgare, Apiaceae) exhibited previously undescribed disease symptoms. The lower stems in contact with soil developed a brown decay and leaves on these stems became chlorotic. White mycelium and orange sporodochia were observed on affected tissues near the soil line. Diseased stems later wilted, died, and resulted in reduced quality of the fennel; these plants were not harvested. Disease distribution was patchy and prevalence was approximately 5%. Symptomatic tissues were surface sterilized in a dilute (1%) bleach solution for 3 min and tissues from the margins of the decay were placed into petri plates containing acidified corn meal agar (2 ml of 25% lactic acid/liter). Isolations consistently resulted in the recovery of a presumptive Fusarium species. Isolates were transferred to carnation leaf agar and incubated at 22°C under fluorescent lights for 10 days. Morphologies of all isolates were identical, with macroconidia being long and slender, slightly curved, with elongated, bent apical cells and notched basal cells. Conidia were borne on monophialides. Microconidia were sparse and chlamydospores were not observed. For two isolates, a portion of the translation elongation factor 1-alpha gene (TEF) was amplified with primers ef1 and ef2 (3). Based on a comparison of 668 base pairs, both isolates had the same sequence, which differed by one base pair from an accession (GQ915502.1) of Fusarium avenaceum in GenBank. The same single base pair also separated the two fennel isolates from an isolate of F. avenaceum (GL 13) previously recovered from Eustoma grandiflorum (=Lisianthus russellianus) (2). Thus, both morphological and molecular criteria support identification of the recovered fungus as F. avenaceum (Fries) Saccardo. Partial TEF sequences were deposited in GenBank (Accession Nos. JN254784, JN254785, and JN254786 for the two fennel isolates and GL 13, respectively). All isolates are archived in the Department of Plant Pathology at University of California, Davis. Pathogenicity was tested by cutting shallow slits into fennel stems, inserting one colonized agar plug into each cut, and wrapping the stems with Parafilm. Five isolates from fennel were tested on 10 stems each. Control plants were inoculated with uncolonized agar plugs. Plants were maintained at 24 to 26°C in a greenhouse. After 6 to 8 days, a brown decay developed on 70 to 90% of Fusarium-inoculated stems at the points of inoculation. Foliage later became chlorotic and F. avenaceum was recovered from all symptomatic stems. Control plants were symptomless. The experiment was completed two times and results were the same. In addition, F. avenaceum isolate GL13 from E. grandiflorum (2) was inoculated onto fennel plants with the same method. However, these inoculated plants remained symptomless. To our knowledge, this is the first report of a stem and crown rot disease of fennel caused by F. avenaceum. Apparently, the only other published account of a Fusarium disease of fennel is root rot caused by F. solani (1). The inability of the Eustoma isolate of F. avenaceum to cause disease in fennel suggests that these two crown rot pathogens may have restricted host ranges. References: (1) J. H. Gupta and V. P. Srivastava. Indian J. Mycol. Plant Pathol. 8:206, 1979. (2) S. T. Koike et al. Plant Dis. 80:1429, 1996. (3) K. O'Donnell et al. Proc. Nat. Acad. Sci. U.S.A. 95:2044, 1998.

scholarly journals First Report of Fusarium solani Causing Stunt on Lisianthus

Plant Disease ◽  
2001 ◽  
Vol 85 (4) ◽  
pp. 443-443 ◽  
Author(s):  
S. Wolcan ◽  
G. Lori ◽  
L. Ronco
Keyword(s):  
Methyl Bromide ◽  
Fusarium Solani ◽  
Stem Rot ◽  
Buenos Aires Province ◽  
Eustoma Grandiflorum ◽  
Basal Stem Rot ◽  
First Report ◽  
Flower Production ◽  
Pathogenicity Tests ◽  
The Mean

Fusarium solani Mart. (Sacc.) is the causal agent of stem rot and damping-off of lisianthus (Eustoma grandiflorum (Raf.) Shinn.) (1). Since the end of the 1980s, when this flower crop was introduced in Argentina, it has been affected by a basal stem rot (2). A previously undescribed disease was observed in 100% of the greenhouses in the Buenos Aires Province that grow lisianthus. Symptoms that developed after seedlings were transplanted included stunting, shortened internodes with reduced stem diameter, and small narrow leaves that were a dull green color. Some affected plants turned yellow-brownish and died 2 to 3 months after transplanting. Other plants recovered but produced low quality flowers later than normal. A third group of plants remained stunted (5 to 10 cm high) until the last flower harvest (about 8 to 10 months). F. solani was consistently isolated from basal stems and roots of diseased plants. For pathogenicity tests, inoculum was produced by culturing the fungus for 10 days in petri dishes containing sterile moistened rice. Inoculum was air dried, crushed, and mixed with soil that had been autoclaved at 112°C for 40 min on each of two consecutive days. The propagules in the soil were estimated by soil plate dilutions on the Nash & Snyder-PCNB medium at a ratio of about 104 CFU/g soil. Twenty plants of each cultivar Echo White and Echo Blue, whose roots had been pruned, were planted in both infested and noninfested soil. After about 40 days, stunting was observed in 85% of the inoculated plants, while controls remained asymptomatic. F. solani was reisolated from symptomatic plants, thus fulfilling Koch's postulates. A test also was conducted in a commercial greenhouse that produced lisianthus for several years, in which healthy plants were planted in three plots fumigated with methyl bromide and in three nonfumigated plots. The mean cfu/g soil of F. solani in the methyl-bromide treated plots was 5 × 102 and 1.6 × 104 CFU/g in the nontreated plot. After 120 days, the incidence of stunting in the treated plots was 0.6 and about 88% in the control plots. F. solani was recovered from symptomatic plants. Because disinfestation of soil is generally practiced in flower production, stunted plants are limited and can be confused with root problems. This is the first report of F. solani causing stunt on lisianthus. References: (1) J. J. Taubenhaus and W. N. Ezekiel. Phytopathology 24:19, 1934. (2) S. M. Wolcan and G. A. Lori. Invest. Agr. Prot. Veg. 11:465, 1996.

scholarly journals First Report of Stem Rot of Papaya Caused by Fusarium solani Species Complex in Brazil

Plant Disease ◽  
2013 ◽  
Vol 97 (1) ◽  
pp. 140-140 ◽  
Author(s):  
K. C. Correia ◽  
B. O. Souza ◽  
M. P. S. Câmara ◽  
S. J. Michereff
Keyword(s):  
Dna Sequences ◽  
Fusarium Solani ◽  
Species Complex ◽  
Morphological Characteristics ◽  
Molecular Techniques ◽  
Northeastern Brazil ◽  
Stem Rot ◽  
Morphological Identification ◽  
Single Spore ◽  
First Report

In October 2010, 2-year-old papaya (cv. Hawaii) trees with high incidence of stem rot were observed during a survey conducted in Rio Grande do Norte state, northeastern Brazil. Stems showing reddish brown-to-dark brown symptoms were collected and small pieces (4 to 5 mm) of necrotic tissues were surface sterilized for 1 min in 1.5% NaOCl, washed twice with sterile distilled water, and plated onto potato dextrose agar (PDA) amended with 0.5 g liter–1 streptomycin sulfate. Plates were incubated at 25°C with a 12-h photopheriod for 4 days. Pure cultures with white, fluffy aerial mycelia were obtained by subculturing hyphal tips onto PDA. Identification was made using morphological characteristics and DNA based molecular techniques. Colonies grown on PDA and Spezieller Nährstoffarmer agar (SNA) for 10 days at 25°C with a 12-h photoperiod were used for morphological identification (3). The fungus produced cream sporodochia and two types of spores: microconidia were thin-walled, hyaline, ovoid, one-celled, and 6.8 to 14.6 × 2.3 to 4.2 μm; macroconidia were thick walled, hyaline, slightly curved, 3- to 5-celled, and 25.8 to 53.1 × 3.9 to 5.7 μm. Fifty spores of each type were measured. Rounded, thick-walled chlamydospores were produced, with two to four arranged together. On the basis of morphological characteristics (1), three fungal isolates (CMM-3825, CMM-3826, and CMM-3827) were identified as Fusarium solani (Mart.) Sacc. and were deposited in the Culture Collection of Phytopathogenic Fungi of the Universidade Federal Rural de Pernambuco (Recife, Brazil). Single-spore isolates were obtained and genomic DNA of the isolates was extracted and a portion of the translation elongation factor 1-alpha (EF1-α) gene of the isolates was amplified and sequenced (2). When compared with sequences available in the GenBank and Fusarium-ID databases, DNA sequences of the three isolates shared 99 to 100% sequence identity with F. solani species complex (GenBank Accession Nos. JF740784.1, DQ247523.1, and DQ247017.1). Representative sequences of the isolates were deposited in GenBank (Accession Nos. JQ808499, JQ808500, and JQ808501). Pathogenicity tests were conducted with four isolates on 3-month-old papaya (cv. Hawaii) seedlings. Mycelial plugs taken from the margin of actively growing colonies (PDA) of each isolate were applied in shallow wounds (0.4 cm in diameter) on the stem (center) of each plant. Inoculation wounds were wrapped with Parafilm. Control seedlings received sterile PDA plugs. Inoculated and control seedlings (10 each) were kept in a greenhouse at 25 to 30°C. After 2 weeks, all inoculated seedlings showed reddish brown necrotic lesions in the stems. No symptoms were observed in the control plants. The pathogen was successfully reisolated from symptomatic plants to fulfill Koch's postulates. To our knowledge, this is the first report of F. solani species complex causing papaya stem rot in Brazil. Papaya is an important fruit crop in the northeastern Brazil and the occurrence of this disease needs to be taken into account in papaya production. References: (1) C. Booth. Fusarium Laboratory Guide to the Identification of the Major Species. CMI, Kew, England, 1977. (2) D. M. Geiser et al. Eur. J. Plant Pathol. 110:473, 2004. (3) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA, 2006.

scholarly journals First Report of Maize Stalk Rot Caused by Fusarium nelsonii in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Xiaojie Zhang ◽  
Cheng Guo ◽  
Chunming Wang ◽  
Tianwang Zhou
Keyword(s):  
Fusarium Species ◽  
Morphological Characteristics ◽  
Molecular Characteristics ◽  
Conidial Suspension ◽  
Basal Cells ◽  
Sterile Water ◽  
Single Spore ◽  
First Report ◽  
Stalk Rot ◽  
Maize Plants

Maize (Zea Mays L.) is one of the main crops in Ningxia Province, China, and stalk rot has become a serious disease of maize in this area. Infected plants showed softening of the stalks at lower internodes, which lodged easily and died prematurely during grain filling, and the pith tissue internally appeared to be disintegrating and slightly brown to reddish. In September 2018, symptomatic tissue was collected from seventeen locations in Ningxia. The incidence ranged from 5% to 40% in surveyed fields, reaching as high as 86% in certain plots. The discolored stalk pith tissues from the lesion region were cut into small pieces (approximately 0.5 × 0.2 cm), superficially disinfected with 75% ethanol for 1 min and rinsed three times with sterile water before plating on potato dextrose agar (PDA) medium with chloromycetin. The purified strains were obtained by single-spore separation and transferred to PDA and carnation leaf agar (CLA) medium. Morphological and molecular characteristics confirmed the presence of nine Fusarium species in these samples, including Fusarium graminearum species complex and Fusarium verticillioides. Four isolates of Fusarium nelsonii were recovered from samples collected in Shizuishan and Wuzhong. On PDA plates, the floccose to powdery, white to rose-colored aerial mycelia were produced and covered plates after 8 days of incubation, producing abundant mesoconidia and chlamydospores. Mesoconidia were fusiform or lanceolate until slightly curved with 0-3 septa, and chlamydospores were initially smooth and transparent, and became verrucous and light brown. Macroconidia produced in CLA were straight or curved and falcate, usually having 3-5 septa, with beak-shaped strongly curved apical cells and foot-shaped basal cells. Two isolates (SS-1-7 and ZY-2-2) were selected for molecular identification, and the total DNA was extracted using a fungal genomic DNA separation kit (Sangon Biotechnology, Shanghai, China). Sequence comparison of EF-1α (GenBank accession numbers MW294197 and MW294198) and RPB2 (Accession MW294176 and MW294177) genes showed 97% homology with the sequences of F. nelsonii reported in GenBank (accession MN120760 for TEF and accession MN120740 for RPB2). Pathogenicity tests with two isolates (SS-1-7 and ZY-2-2) were performed by individually inoculating five 10-leaf stage maize plants at between the 2nd and 3rd stem nodes from the soil level with 20 μl conidial suspension at a concentration of 106 conidia/ml as described by Zhang et al. (2016). Five maize plants inoculated with sterile water were used as controls. The inoculated plants were kept at 25 ± 0.5°C in the greenhouse with a photoperiod of 12 h. After 30 days, all plants inoculated with the conidial suspension formed an internal dark brown necrotic area around the inoculation site, whereas the control plants showed no symptoms. The pathogen was re-isolated from the necrotic tissue of the inoculated plants and identified by morphological characteristics as F. nelsonii. This species was first described by Marasas et al. (1998), and it is expanding its host range and has been isolated from sorghum, Medicago, wheat, and cucumber (Ahmad et al. 2020). The pathogen should be paid more attention owing to a serious risk of trichothecene and aflatoxin contamination (Astoreca et al. 2019; Lincy et al. 2011). To our knowledge, this is the first report of maize stalk rot caused by F. nelsonii in China. References: Ahmad, A., et al. 2020. Plant disease.1542 https://doi.org/10.1094/PDIS-11-19-2511-PDN Astoreca, A. L., et al. 2019. Eur. J. Plant Pathol. 155:381. Lincy, S. V., et al. 2011. World J. Microbiol. Biotechnol. 27:981. Marasas, W. F. O., et al. 1998. Mycologia 90:505. Zhang, Y., et al. 2016. PLoS Pathog. 12:e1005485. Funding: This research was financially supported by National R & D Plan of China (No.2019QZKK0303); Ningxia Agriculture and Forestry Academy Science and Technology Cooperation Project (DW-X-2018019)

scholarly journals First Report of Fusarium solani Causing Root Rot of Olive in Southeastern Argentina

Plant Disease ◽  
2011 ◽  
Vol 95 (11) ◽  
pp. 1476-1476 ◽  
Author(s):  
B. A. Perez ◽  
O. M. Farinon ◽  
M. F. Berretta
Keyword(s):  
Fusarium Solani ◽  
Root Rot ◽  
Buenos Aires ◽  
Average Length ◽  
Fusarium Species ◽  
Morphological Identification ◽  
Buenos Aires Province ◽  
Blue Color ◽  
First Report ◽  
Olive Trees

In Argentina, olive (Olea europaea L.) is cultivated in the mountainous, warm, arid northwest (Andes range), where Fusarium solani (blue sporodochia) is frequently found to be causing death of nursery and young field plants (1). Recently, olive orchards were established more than 1,600 km to the southeast (Pampas) in a plain with a temperate and humid climate and in the arid Patagonia, both influenced by the Atlantic Ocean. This area includes part of Buenos Aires and Rio Negro provinces. In March 2008, 10-year-old ‘Barnea’ olive trees with high incidence of root rot, dried leaves, dead branches, and dead plants were observed in the Coronel Dorrego District of Buenos Aires Province, where oat, barley or other cereals are planted between rows of olive trees. Planting material originated from olive nurseries located in Mendoza Province, 1,200 km from Coronel Dorrego. Diseased roots were disinfected in 2% NaOCl and 70% ethanol, cut into small pieces, plated onto rose bengal-glycerin-urea medium, and incubated at 20°C with a 12-h photopheriod. A fungus was purified through successive transfers of hyphal tips from the margin of a sparsely growing colony onto 2% water agar (2). Colonies grown on Spezieller Nährstoffarmer agar (3) and carnation leaf-piece agar were used for morphological identification, and those on grown on potato dextrose agar were used for evaluation of pigmentation and colony growth rate. Sporodochium color, cream, was typical of F. solani (Mart.) Sacc. This isolate was deposited in the IMYZA Microbial Collection as INTA-IMC 73. Mycelium was cultured in liquid Czapek-Dox medium supplemented with sucrose, peptone, yeast extract, sodium nitrate, and vitamins for 4 days and fungal DNA was obtained with a DNA extraction kit. Primers ITS1 and ITS4 were used to amplify the internal transcribed spacer (ITS) region of ribosomal genes. The purified PCR product was sequenced and the DNA sequence compared with GenBank records. The sequence shared 100% identity with 27 entries for F. solani and 97% identity with F. solani obtained from olive in Nepal (4), corresponding to EU912432 and EU912433. The nucleotide sequence was registered in GenBank as JF299258. Pathogenicity was confirmed on ‘Manzanilla’ plants at the eight-leaf stage. Pieces of water agar with mycelium were applied to small wounds at the stem base and on roots of 10 plants and were covered with cotton soaked in sterile distilled water. Plants were incubated at 20°C and a 14-h photoperiod. On control plants, water agar pieces without mycelium were applied to the wounds. After 33 days, inoculated plants showed dark brown lesions (average length 1.4 cm) and leaf chlorosis. Two plants showed wilting with leaves remaining attached to branches. F. solani was reisolated from roots and stem bases of inoculated plants. Controls remained asymptomatic. To our knowledge, this is the first report of F. solani occurring on olive in the temperate part of the Pampas of Argentina where cereals, which are susceptible to Fusarium species, are grown with olive trees. Sporodochium color (cream) of these isolates differed from the blue color of previously reported isolates of F. solani on olive in northwestern Argentina (1). References: (1) S. Babbitt et al. Plant Dis. 86:326, 2002. (2) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA, 2006. (3) H. I. Nirenberg. Releases Fed. Biol. Res. Center Agric. For. (Berlin-Dahlem) 169:1, 1976. (4) A. M. Vettraino et al. Plant Dis. 23:200, 2009.

scholarly journals First Report of Fusarium Crown and Root Rot Caused by Fusarium solani on St. John's-Wort in Argentina

Plant Disease ◽  
2004 ◽  
Vol 88 (9) ◽  
pp. 1050-1050 ◽  
Author(s):  
S. Gaetán ◽  
M. Madia ◽  
R. Cepeda
Keyword(s):  
Fusarium Solani ◽  
Root Rot ◽  
Fusarium Species ◽  
Buenos Aires Province ◽  
Single Spore ◽  
Susceptible Host ◽  
First Report ◽  
St John’S Wort ◽  
St John's Wort ◽  
Crown And Root Rot

Since 2001, 15 to18% of commercial plantings of the medicinal plant St. John's-wort (Hypericum perforatum L.) in Buenos Aires Province, Argentina were affected by a new disease. Disease symptoms of crown and root rot, wilting, chlorosis, and necrosis of the leaves appeared in circular-to-irregular shaped sectors of 12- to 14-month-old plants. Symptoms began with foliage turning yellow followed by an irregular, brown necrosis of the leaf margins. Lesions coalesced to form large necrotic areas causing a severe defoliation of the basal and upper leaves. A soft rot affected the crown and roots causing a complete maceration of these tissues. Infected plants broke off easily because the crown region and the roots were destroyed. As the disease developed, a dark brown discoloration girdled the stems that progressed above the soil line to the apex. The infected stems became dry and breakable. Finally, the affected plants died. Segments (1 cm long) were taken from roots and rotted crowns of diseased plants, dipped in 70% ethanol, surface sterilized with NaOCl (1%) for 1 min, and rinsed in sterile water. Each segment was blotted dry and placed on potato dextrose agar. Plates were incubated in the dark at 26°C for 4 to 7 days. The predominate fungus isolated from the diseased tissue was identified as Fusarium solani (Mart.) Sacc. (1). Koch's postulates were completed by dipping the roots of seedlings in a 2 × 106 conidia per ml suspension of a single spore isolate for 45 min. Plants were repotted (20 inoculated and 10 controls) in a sterilized soil mix (soil/sand 2:1) and held in the greenhouse at 23 to 26°C. Characteristic symptoms identical to the original developed on 90% of inoculated plants within 2 weeks after inoculation. Symptoms included wilt and collapse, crown and root rot, and death of the plants. The fungus was recovered from symptomatic tissues. Control plants dipped into distilled water remained healthy. The experiment was repeated, and the results were identical to the first inoculations. To our knowledge, this is the first report of St. John's-wort as a susceptible host of F. solani. Reference: (1) P. E. Nelson et al. Fusarium species. An Illustrated Manual for Identification. Pennsylvania State University Press, University Park, 1983.

scholarly journals First Report of Zucchini Collapse by Fusarium solani f. sp. cucurbitae Race 1 and Plectosporium tabacinum in Italy

Plant Disease ◽  
2007 ◽  
Vol 91 (3) ◽  
pp. 325-325 ◽  
Author(s):  
S. Vitale ◽  
M. Maccaroni ◽  
A. Belisario
Keyword(s):  
Fusarium Solani ◽  
Fusarium Species ◽  
Morphological Characteristics ◽  
Its Region ◽  
Conidial Suspension ◽  
Single Spore ◽  
Running Water ◽  
First Report ◽  
Race 1 ◽  
Rot Disease

Zucchini plant collapse has been often associated with Fusarium solani f. sp. cucurbitae race 1, which is the causal agent of Fusarium crown and foot rot disease of cucurbits. In Italy, F. solani f. sp. cucurbitae race 1 has been reported on zucchini (Cucurbita pepo) in a greenhouse in the Tuscany Region (4). In spring 2005, a severe outbreak was observed on zucchini in a vast area of cultivation in the province of Venice. Isolations from necrotic vessels gave more than 20 single-spore cultures. On the basis of morphological characteristics, they were identified as F. solani (2) and Plectosporium tabacinum (3). The internal transcribed spacer (ITS) region of rDNA was amplified and sequenced. A fragment of 454 and 531 bp was 99% homologous with sequence PSU66732 and AF150472 of F. solani f. sp. cucurbitae race 1 and P. tabacinum, respectively, in the NCBI database. The nucleotide sequences have been assigned Accession No. AM408782 for F. solani f. sp. cucurbitae race 1 and AM408781 for P. tabacinum. Pathogenicity tests were conducted with four isolates of each species on 15-day-old zucchini plants and on fruit. Plants were inoculated by dipping the roots in a conidial suspension of 106 spores ml-1 for 10 min. Control plants were dipped in sterile water. Five replicates for the inoculated and control plants were used. All plants were maintained in a greenhouse at approximately 24°C. After 14 days, inoculations with F. solani f. sp. cucurbitae race 1 gave symptoms of a cortical rot at the base of the stem with a progressive yellows and wilting of leaves, while plants inoculated with P. tabacinum displayed a moderate wilting. Fruit were washed under running water, disinfected with a solution of 3% sodium hypochlorite and 5% ethanol for 1 min, and inoculated with 6-mm-diameter mycelial plugs cut from the margin of 10-day-old cultures grown on PDA. Plugs were inserted into holes (approximately 2 mm deep) made with a sterile 7-mm-diameter cork borer. Five replicates per isolate were used. Fruit were kept at room temperature (22 to 24°C) in a moist chamber. All isolates induced symptoms of fruit rotting 10 days after inoculation. All controls remained healthy. The colonies reisolated from the inoculated plants and fruit were morphologically identical to the original isolates. The results obtained proved that F. solani f. sp. cucurbitae race 1 can be considered the major pathogen in zucchini collapse, at the same time P. tabacinum may play a role in this syndrome as reported for other cucurbits (1). To our knowledge, this is the first report of zucchini plant collapse caused by F. solani f. sp. cucurbitae race 1 and P. tabacinum, and the first report of P. tabacinum on zucchini in Italy. References: (1) V. J. Garcia-Jimenez et al. EPPO Bull. 30:169, 2000. (2) P. E. Nelson et al. Fusarium Species: An Illustrated Manual for Identification. Pennsylvania State University, University Park, 1983. (3) M. E. Palm et al. Mycologia 87:397, 1995. (4) G. Vannacci and P. Gambogi. Phytopathol. Mediterr. 19:103, 1980.

scholarly journals Phylogeny and Mycotoxin Profile of Pathogenic Fusarium Species Isolated from Sudden Decline Syndrome and Leaf Wilt Symptoms on Date Palms (Phoenix dactylifera) in Tunisia

Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 463
Author(s):  
Amal Rabaaoui ◽  
Chiara Dall’Asta ◽  
Laura Righetti ◽  
Antonia Susca ◽  
Antonio Logrieco ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Fusarium Solani ◽  
Fusarium Species ◽  
Elongation Factor ◽  
Phoenix Dactylifera ◽  
Fusarium Proliferatum ◽  
Fruit Rot ◽  
Morphological Identification ◽  
Single Strain ◽  
Date Palms

In 2017–2018, extensive symptoms of sudden decline and fruit rot were observed on date palms in southern Tunisia. Samples of diseased plants were randomly collected in six localities. Based on morphological identification, Fusarium was the most frequent fungal genus detected. A sequencing of translation elongation factor, calmodulin, and second largest subunit of RNA polymerase II genes was used to identify 63 representative Fusarium strains at species level and investigate their phylogenetic relationships. The main species detected was Fusarium proliferatum, and at a much lesser extent, Fusarium brachygibbosum, Fusarium caatingaense, Fusarium clavum, Fusarium incarnatum, and Fusarium solani. Pathogenicity on the Deglet Nour variety plantlets and the capability to produce mycotoxins were also assessed. All Fusarium species were pathogenic complying Koch’s postulates. Fusarium proliferatum strains produced mainly fumonisins (FBs), beauvericin (BEA), and, to a lesser extent, enniatins (ENNs) and moniliformin (MON). All F. brachygibbosum strains produced low levels of BEA, diacetoxyscirpenol, and neosolaniol; two strains produced also T-2 toxin, and a single strain produced HT-2 toxin. Fusarium caatingaense, F. clavum, F. incarnatum produced only BEA. Fusarium solani strains produced MON, BEA, and ENNs. This work reports for the first time a comprehensive multidisciplinary study of Fusarium species on date palms, concerning both phytopathological and food safety issues.

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