Crown and Root Infection of Lisianthus Caused by Fusarium solani in South Africa

Cultivation of lisianthus (Eustoma grandiflorum (Raf.) Shinn.) is a minor industry in South Africa, with only a few growers producing the crop commercially. Commercial production at a location in Gauteng Province is hampered by rotting of the crowns and roots of plants that result in mortality of as much as 22% of the plants. At advanced stages of infection, the crowns of affected plants characteristically are covered with masses of fusoid, curved hyalophragmospores. Crowns and roots of symptomatic plants that were submitted by the grower in January 2003 were surface disinfested by immersing for 2 min in a 3% solution of sodium hypochlorite, and segments excised from the plant tissue were plated on potato dextrose agar supplemented with 50 mg l-1 of rifampicin. Fusarium solani (Mart.) Appel & Wollenw. (1), was consistently and exclusively isolated from the segments. Teleomorph Nectria haematococca Berk. & Broome, commonly developed in culture after incubation for 4 to 6 weeks, although no sexual structures were observed on infected plants. A spore suspension containing 104 micro- and macroconidia ml-1 was prepared for each of two single-conidial isolates of F. solani. Using a 0.8-mm-diameter hypodermic needle, 100 μl of each suspension was injected subepi-dermally into the crown of each of three 1-month-old disease-free lisian-thus plantlets (cv. Texas Blue Bell) growing in 500-ml plastic pots filled with sterilized vermiculite. In addition, each suspension was incorporated at 2% (vol/vol) into three pots with sterile vermiculite, and a plantlet was planted in each pot. Control plantlets were treated similarly, but with sterile distilled water. All inoculated plantlets developed crown rot and wilted within 2 weeks while maintained at 28°C in a greenhouse, regardless of mode of inoculation, and F. solani was readily reisolated from their crowns and roots. Control plantlets remained symptomless and did not yield F. solani. Crown and root infection of lisianthus by F. solani has been described (2,3), but to our knowledge, this is the first report of the disease in South Africa. References: (1) P. E. Nelson et al. Fusarium species: An Illustrated Manual for Identification. Pennsylvania State University Press, University Park. 1983. (2) J. J. Taubenhaus and W. N. Ezekiel. Phytopathology 24:19, 1934. (3) S. Wolcan et al. Plant Dis. 85:443, 2001.

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

Plant Disease ◽

10.1094/pdis-04-11-0358 ◽

2012 ◽

Vol 96 (1) ◽

pp. 145-145 ◽

Cited By ~ 1

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.

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Crown Rot of Zucchini Squash Caused by Fusarium solani f. sp. cucurbitae in Almería Province, Spain

Plant Disease ◽

10.1094/pdis-92-7-1137b ◽

2008 ◽

Vol 92 (7) ◽

pp. 1137-1137 ◽

Cited By ~ 5

Author(s):

J. Gómez ◽

J. M. Guerra-Sanz ◽

M. C. Sánchez-Guerrero ◽

Y. Serrano ◽

J. M. Melero-Vara

Keyword(s):

Fusarium Solani ◽

Morphological Characteristics ◽

Crown Rot ◽

State University ◽

Pennsylvania State University ◽

Its1 Region ◽

5.8S Rdna ◽

Race 1 ◽

Petri Plate ◽

The One

Cucumber, melon, watermelon, and zucchini are intensively cropped in the southern part of Spain where approximately 20,000 ha of the crops are grown in greenhouses. In the spring of 2007, zucchini plants (Cucurbita pepo) at the fruit-bearing stage in three commercial plastichouses in Almería exhibited necrosis on the basal stem, wilt, and death. The incidence of dead plants was 20 to 30%. Fusarium solani was consistently isolated from the basal stems of symptomatic plants on potato dextrose agar (PDA). Cultures of six single-hyphal transfers were identified on the basis of molecular sequences and morphological characteristics (2). Sequences of ribosomal DNA from ITS1 region, 5.8S rDNA, and ITS2 were identical for all six isolates of F. solani. The rDNA sequence of isolate Fscl-3 of F. solani was deposited as GenBank Accession No. AM940070. The pathogenicity of these six isolates of F. solani was tested in two experiments conducted in one plastichouse in Almería. Pregerminated seeds of zucchini cv. Consul were sown in 1-liter containers filled with vermiculite on 21 May and 22 June, 2007 (experiments 1 and 2, respectively). Plants at the one- to two-true-leaf stage or younger were inoculated with a soil drench of 2.0 to 8.4 × 105 propagules per ml). One colonized PDA petri plate of each isolate was blended and homogenized in 500 ml of distilled water. Inoculum (50 ml per plant) was poured around the stem of zucchini plants growing in vermiculite. The experimental design was a randomized complete block with three replicates with each plot comprising four plants (one plant per container). In both experiments, 12 uninoculated plants of the same cultivar served as controls. Plants were maintained for 1 month following inoculation in a greenhouse with mean temperatures ranging between 20.7 and 24.6°C and 23.3 to 29.8°C for experiments 1 and 2, respectively. Wilting first occurred 9 days after inoculation, and 14 days later, all plants inoculated with the F. solani isolates died. Inoculated plants exhibited lesions on the stem base without rot of secondary roots. At the end of the experiment, the uninoculated plants remained asymptomatic. Results of experiment 2, with higher temperatures, were similar. The pathogen was consistently recovered from symptomatic plants in both experiments, fulfilling Koch's postulates. Although F. solani f. sp. cucurbitae race 1 was reported in field squash (C. maxima) in the province of Valencia of east-central Spain (1), to our knowledge, this is the first report of F. solani as the causal agent of crown rot of zucchini plants in plastichouses in the Almería Province of Spain, one of the world's largest concentrations of greenhouses. References: (1) J. García-Jiménez et al. Plant Dis. 81:1216, 1997. (2) C. M. Messiaen and R. Cassini. Taxonomy of Fusarium. Page 427 in: Fusarium: Diseases, Biology, and Taxonomy. P. E. Nelson et al., eds. Pennsylvania State University, University Park, 1981.

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Fusarium Crown and Root Rot of Tarragon in California Caused by Fusarium solani

Plant Disease ◽

10.1094/pdis-01-11-0058 ◽

2011 ◽

Vol 95 (6) ◽

pp. 768-768 ◽

Cited By ~ 1

Author(s):

S. T. Koike

Keyword(s):

Fusarium Solani ◽

Root Rot ◽

Fusarium Species ◽

Aerial Mycelium ◽

State University ◽

Root Cortex ◽

Perennial Plant ◽

Initial Symptoms ◽

Crown And Root Rot ◽

Rot Disease

Tarragon, also known as estragon or dragon's-wort (Artemisia dracunculus), is a perennial plant in the Asteraceae. Tarragon is grown for use in cooking as a fresh and dried herb. In May 2010, commercial tarragon grown in a field on California's central coast was affected by a previously undescribed disease. Initial symptoms consisted of chlorosis of leaves and wilting of shoot tips. As the disease progressed, entire shoots and branches turned brown and died. The plant crown epidermis and cortex and the upper cortex of the main roots turned brown with occasional black streaking. Diseased plants died several weeks after the onset of wilting. A Fusarium species was consistently isolated from symptomatic crown and root tissues. On carnation leaf agar (CLA) incubated under lights, the isolates produced stout, slightly curved macroconidia having blunt apical cells. One- and two-celled oval to cylindrical microconidia were abundant and born in false heads on extremely long monophialides. Chlamydospores were present in 1-month-old cultures. On potato dextrose agar incubated under lights, the isolates produced abundant white aerial mycelium with bluish coloration of the culture surface. The isolates were identified as Fusarium solani (2). Pathogenicity tests were conducted using six isolates, with inoculum produced on CLA. For each isolate, 250 ml of a spore suspension (1 × 106 conidia/ml) were poured onto the roots of 10-cm potted tarragon plants. Ten plants were inoculated for each of the six isolates. A control set of tarragon was treated with 250 ml of water. All plants were maintained in a greenhouse set at 24 to 25°C. After 8 weeks, plants inoculated with the spore suspensions began to show wilting and browning of leaves. Crown epidermis and cortex and root cortex tissues were brown; Fusarium solani was reisolated from the crowns and roots. The experiment was repeated and the results were the same. To my knowledge, this is the first report of F. solani causing a crown and root rot disease of tarragon. The disease caused significant damage with approximately 50% of the commercial field affected. The other Fusarium species previously reported on tarragon is an uncharacterized F. oxysporum isolated from roots of plants grown in California (1). References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , March 8, 2011, (2) P. E. Nelson et al. Fusarium Species: An Illustrated Manual for Identification. Pennsylvania State University Press, University Park, PA, 1983.

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Ascertaining the Role of Leadership on Employee Satisfaction in Market and Social Research Industries in Gauteng Province of South Africa Using Qualitative Research

International Journal on Leadership ◽

10.21863/ijl/2015.3.2.009 ◽

2015 ◽

Vol 3 (2) ◽

Author(s):

Kingstone Mutsonziwa ◽

Philip Serumaga-Zake

Keyword(s):

South Africa ◽

Employee Satisfaction ◽

Quantitative Research ◽

Social Research ◽

Labour Productivity ◽

Working Environment ◽

Gauteng Province ◽

Career Growth ◽

Quantitative Results ◽

Mixed Approach

This paper is based on the study a Doctor of Business Leadership (DBL) thesis titled A Statistical Model for Employee Satisfaction in the Market and Social Research Industries in Gauteng Province. The purpose of this study was to identify the attributes that affect employee satisfaction in the Market and Social Research Industries in Gauteng Province, South Africa. In order to address the overall objective of this study, the researcher used a two-tiered (mixed) approach in which both qualitative and quantitative research methodologies were used to complement and enrich the results. This paper is only based on the qualitative component of the study on leadership aspects based on six leaders (two from Social research and four from Market research) that were interviewed. The leaders were selected based on their knowledge of the industry and the expertise they have. Participation in the survey was voluntary. This paper illustrates the power of the qualitative techniques to uncover or unmask the leadership aspects in the Market and Social Research Industries and also gives the human touch to the quantitative results. It was found that leadership and management within the Market and Social Research Industries in Gauteng Province must ensure that they are accommodative in terms of mentoring their subordinates. The industry is driven by quality driven processes and strong leadership. More importantly, issues of a good working environment, remuneration, career growth, and recognition must always be addressed in order to increase employee satisfaction, reduce staff turnover, and attempt to optimize labour productivity. The qualitative findings also help a deeper understanding of leadership within the industry.

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Municipal asset operations and maintenance performance in metropolitan and rural municipalities in Gauteng Province and Vhembe District Local Municipalities, South Africa

Cogent Engineering ◽

10.1080/23311916.2021.1935409 ◽

2021 ◽

Vol 8 (1) ◽

pp. 1935409

Author(s):

Peter Bikam ◽

James Chakwizira

Keyword(s):

South Africa ◽

Gauteng Province ◽

Local Municipalities ◽

Operations And Maintenance ◽

Rural Municipalities ◽

Vhembe District ◽

Maintenance Performance

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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 ◽

10.3390/toxins13070463 ◽

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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