scholarly journals Fusarium Wilt of African Daisy (Osteospermum sp.) Caused by Fusarium oxysporum in Italy

Plant Disease ◽  
2004 ◽  
Vol 88 (3) ◽  
pp. 309-309 ◽  
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
M. L. Gullino
Keyword(s):  
Fusarium Oxysporum ◽  
Vascular Tissue ◽  
Vascular System ◽  
Selective Medium ◽  
Northern Italy ◽  
Wilt Disease ◽  
Pathogenicity Test ◽  
Conidial Suspension ◽  
Average Temperature ◽  
Brown Discoloration

During the fall of 2002, African daisy (Osteospermum sp.) plants showing symptoms of a wilt disease were observed in a commercial, nonheated glasshouse in Albenga in northern Italy. Wilted plants were first observed when outside temperatures were between 15 and 28°C. Symptoms were first observed on seedlings 40 days after they had been transplanted into pots. The vascular tissues of affected plants appeared brown. These plants were stunted and developed yellowed leaves with brown or black streaks in the vascular system. The vascular streaks in the yellow leaves extended from the crown and were continuous with a brown discoloration in the vascular system of the crown and upper taproot. Fusarium oxysporum was consistently and readily isolated from symptomatic vascular tissue onto a Fusarium-selective medium (1). Healthy, rooted, 40-day-old plants were inoculated by root-dip with a conidial suspension (1 × 107 CFU/ml) of three isolates of F. oxysporum obtained from infected plants and transplanted into pots filled with steam-sterilized soil. Noninoculated plants served as control treatments. Plants (10 per treatment) were grown in a glasshouse at an average temperature of 25°C (minimum of 12°C and maximum of 39°C). Wilt symptoms and vascular discoloration in the roots, crown, and veins developed within 20 days on each inoculated plant, while noninoculated plants remained healthy. F. oxysporum was consistently reisolated from infected plants. The pathogenicity test was conducted twice. To our knowledge, this is the first report of F. oxysporum on Osteospermum sp. in Italy or elsewhere in the world. Reference: (1) H. Komada. Rev. Plant Prot. Res. 8:114, 1975.

scholarly journals Fusarium Wilt of Bitterroot (Lewisia cotyledon) in Italy Caused by Fusarium oxysporum

Plant Disease ◽  
2005 ◽  
Vol 89 (6) ◽  
pp. 684-684 ◽  
Author(s):  
A. Garibaldi ◽  
G. Gilardi ◽  
M. L. Gullino
Keyword(s):  
Fusarium Oxysporum ◽  
Vascular Tissue ◽  
Vascular System ◽  
Casein Hydrolysate ◽  
Culture Collection ◽  
Selective Medium ◽  
Pathogenicity Test ◽  
Conidial Suspension ◽  
Climatic Chamber ◽  
Brown Discoloration

During the spring of 2004, bitterroot (Lewisia cotyledon (S. Wats.) B.L. Robins), a flowering perennial of interest for rock gardens, showed symptoms of a wilt disease in several commercial nurseries located in Piedmont (northern Italy). Ten to thirty percent of plants from several different nurseries were affected. Wilted plants were first observed approximately 20 days after being transplanted into containers when outside temperatures ranged from 15 to 22°C. Symptomatic plants were stunted with yellowed leaves and brown-to-black veins. The vascular browning extended into the crown and was continuous with a brown discoloration in the vascular system of the crown and upper taproot. Fusarium oxysporum, identified on the basis of colony and conidia morphology (1), was consistently and readily isolated from symptomatic vascular tissue onto a Fusarium-selective medium (2). Three isolates were transferred to casein hydrolysate and grown for 10 days to produce conidial inoculum. Healthy 30-day-old plants were inoculated by dipping roots into a (1 × 106 CFU/ml) conidial suspension. Plants were then transplanted into pots filled with steam-sterilized soil. Noninoculated plants served as a control. Plants (12 per treatment) were placed in a climatic chamber at 25°C. Wilt symptoms and vascular discoloration in the roots, crown, and veins developed within 20 days on each inoculated plant, while noninoculated plants remained healthy. F. oxysporum was consistently reisolated from symptomatic plants. The pathogenicity test was conducted twice with the same result. One isolate of the pathogen has been deposited in the ATCC culture collection. To our knowledge, this is the first report of F. oxysporum on L. cotyledon in Italy and elsewhere in the world. Currently, this disease is present in several nurseries in the Piedmont Region of Italy. References: (1) C. Booth. Fusarium. CMI, Kew, UK, 1977. (2) H. Komada. Rev. Plant Prot. Res. 8:114, 1975.

scholarly journals First Report of Fusarium oxysporum on Lettuce in Europe

Plant Disease ◽  
2002 ◽  
Vol 86 (9) ◽  
pp. 1052-1052 ◽  
Author(s):  
A. Garibaldi ◽  
G. Gilardi ◽  
M. L. Gullino
Keyword(s):  
Fusarium Oxysporum ◽  
Vascular System ◽  
The United States ◽  
Selective Medium ◽  
Northern Italy ◽  
Infested Soil ◽  
Pathogenicity Test ◽  
First Report ◽  
Vascular Tissues ◽  
Brown Discoloration

In spring 2001, plants of the lettuce cv. Salad Bowl showing symptoms of a wilt disease were observed in several commercial plastic greenhouses near Bergamo, in northern Italy. Wilted plants were first observed during the spring and summer of 2001 when temperatures were between 26 and 35°C. Symptoms were observed in the same area and the same farms in March 2002, in concomitance with a period of high temperatures. Although the distribution of the disease was generally uniform, symptoms were more severe in the central part of the greenhouses where temperatures were warmest. Symptoms were first observed at thinning, when seedlings (30 days old) appeared wilted. Vascular tissues of affected seedlings appeared red or brown. Affected plants were stunted and developed yellow leaves and brown or black streaks in the vascular system. The vascular streaks in the yellow leaves extended from the crown and were continuous with a red-brown discoloration in the vascular system of the crown and upper taproot. Symptoms were typically not visible on the outside of the crowns or roots. Fusarium oxysporum was consistently and readily isolated from symptomatic vascular tissues on a Fusarium-selective medium (2). Seeds of cv. Salad Bowl were planted in steam-sterilized soil artificially infested with 1 × 104 CFU/g soil of each of two isolates of F. oxysporum obtained from infected plants. Plants grown in noninfested soil served as noninoculated control treatments. Plants (25 per treatment) were grown at 25 to 28°C in growth chambers. Wilt symptoms and vascular discoloration of the roots, crown, and veins developed 20 days after seeding for all plants grown in the infested soil, and F. oxysporum was consistently reisolated from infected plants. The pathogenicity test was conducted twice. To our knowledge, this is the first report of F. oxysporum on lettuce in Europe. A wilt of lettuce attributed to F. oxysporum f. sp. lactucae was reported in Japan in 1967 (3) and in the United States in 1993 (1), in the latter case the incitant organism was described as F. oxysporum f. sp. lactucum. References: (1) J. C. Hubbard and J. S. Gerik. Plant Dis. 77:750, 1993. (2) H. Komada. Rev. Plant Prot. Res. 8:114, 1975. (3) T. Matuo and S. Motohashi. Trans. Mycol. Soc. Jpn. 8:13, 1967.

scholarly journals Verticillium Wilt of African Daisy (Osteospermum sp.) in Italy Caused by Verticillium dahliae

Plant Disease ◽  
2005 ◽  
Vol 89 (6) ◽  
pp. 688-688
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
M. L. Gullino
Keyword(s):  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Plant Disease ◽  
Vascular Tissue ◽  
Northern Italy ◽  
Wilt Disease ◽  
Pathogenicity Test ◽  
Conidial Suspension ◽  
Average Temperature ◽  
Food Agric

During the winter of 2004, container-grown African daisy (Osteospermum sp.) plants, cv Seaside, showing symptoms of a wilt disease were observed in an open field in Albenga located in northern Italy. Symptoms were first observed on 120-day-old plants grown in a peat/composted bark/clay/pumice (50:20:10:20) substrate. The vascular tissues of affected plants appeared brown. These plants were stunted and developed yellow leaves with brown or black streaks in the vascular tissue. Verticillium dahliae was consistently and readily isolated from symptomatic vascular tissue when cultured on potato dextrose agar. Healthy rooted plants (40-day-old cv Seaside) were inoculated by root dip with a conidial suspension (5 × 107 CFU/ml) from one of three isolates of V. dahliae isolated from infected plants and transplanted into pots filled with steam-sterilized soil. Noninoculated plants served as control treatments. Plants (10 per treatment) were grown in a glasshouse at an average temperature of 25°C. First wilt symptoms and vascular discoloration in the roots, crown, and veins developed within 15 days on each inoculated plant and become very evident after 50 days. Noninoculated plants remained healthy. V. dahliae was consistently reisolated from inoculated plants. The pathogenicity test was conducted twice. To our knowledge, this is the first report of V. dahliae on Osteospermum sp. in Italy and in Europe. Verticillium wilt has been previously reported on O. fruticosum in California (1). Reference: (1) A. M. French. California Plant Disease Host Index. Calif. Dep. Food Agric. 1989.

scholarly journals Fusarium Wilt of Gerbera in Soil and Soilless Crops in Italy

Plant Disease ◽  
2004 ◽  
Vol 88 (3) ◽  
pp. 311-311 ◽  
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
D. Bertetti ◽  
M. L. Gullino
Keyword(s):  
The Netherlands ◽  
Vascular Tissue ◽  
Vascular System ◽  
Selective Medium ◽  
Northern Italy ◽  
Pathogenicity Test ◽  
Conidial Suspension ◽  
Cut Flowers ◽  
Planting Material ◽  
Red Bull

In 2002, gerbera (Gerbera jamesonii cv. Kaiki) plants that were grown for cut flowers in a soilless cultivation system (rockwool substrate) at Albenga (Savona) in northern Italy were observed exhibiting symptoms of a wilt disease. During the summer of 2002, in a commercial gerbera farm in the province of Imperia (northern Italy), a similar wilt was also observed on cvs. Red Bull, Anedin, and Gud finger that were grown in soil. In both cases, the planting material originated from the Netherlands. During 2003, wilted plants (cvs. Red Bull, Basic, and Cirill) were repeatedly observed in other commercial greenhouses located in the same area. Affected plants were stunted and developed yellowed leaves with initially brown and eventually black streaks in the vascular system. The vascular streaks in the yellow leaves were continuous with a brown discoloration in the vascular system of the crown and upper taproot. In some cases, the leaves of affected plants turned red. From these plants, Fusarium spp. were consistently and readily isolated from symptomatic vascular tissue onto a Fusarium-selective medium (2). Colonies were identified as F. oxysporum after subculturing on potato dextrose agar. Healthy rooted 30-day old plants (cv. Dino) were inoculated by dipping roots into a conidial suspension (5 × 107 conidia per ml) in one of six test isolates of F. oxysporum. Plants were transplanted (1 plant per pot) into pots (3.5 l vol) containing rockwool-based substrate. Noninoculated plants served as control treatments. Plants (21 per treatment) were grown in a glasshouse with an average day temperature of 31°C and night temperature of 25°C (minimum of 20°C and maximum of 42°C). Wilt symptoms and vascular discoloration in the roots, crown, and veins developed within 30 days on each inoculated plant, while noninoculated plants remained healthy. F. oxysporum was consistently reisolated from infected plants. The pathogenicity test was conducted twice. To our knowledge, this is the first report of the presence of F. oxysporum on gerbera in Italy. A wilt of gerbera was described in the Netherlands in 1952 (1) but its presence was not confirmed in further observations (3). Reference: (1) J. Arx and J. A. von Tijdschr. PlZiekt. 58:5, 1952 (2) H. Komada. Rev. Plant Prot. Res. 8:114, 1975. (3) G. Scholten. Neth. J. Plant Pathol. 76:212, 1970.

scholarly journals Fusarium Wilt of Gerbera in Spain in Soilless Crops

Plant Disease ◽  
2007 ◽  
Vol 91 (5) ◽  
pp. 638-638 ◽  
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
A. M. Prados-Ligero ◽  
J. M. Melero-Vara ◽  
M. L. Gullino
Keyword(s):  
Vascular Tissue ◽  
Vascular System ◽  
Casein Hydrolysate ◽  
Personal Communication ◽  
Selective Medium ◽  
Fluorescent Light ◽  
Pathogenicity Test ◽  
Conidial Suspension ◽  
Cut Flowers ◽  
Brown Discoloration

In 2004, gerbera (Gerbera jamesonii cv. Excellence) plants, grown for cut flowers, were observed in a soilless cultivation system (coconut fiber substrate) in one farm in the Cadiz area (southwestern Spain) exhibiting symptoms of a wilt disease. Gerbera represents a relevant crop for the industry in the region, after rose and carnation. Affected plants were stunted and developed yellow leaves with initially brown and eventually black streaks in the vascular system. The vascular streaks in the yellow leaves were continuous with a brown discoloration in the vascular system of the crown and upper taproot. In some cases, the leaves of affected plants turned red. Fusarium spp. was consistently and readily isolated from symptomatic vascular tissue of infected plants onto a Fusarium-selective medium (3). Colonies were identified as F. oxysporum after subculturing on potato dextrose agar on the basis of morphological observations. Pathogenicity tests were carried out by using two monoconidial isolates, compared with an Italian one, obtained from wilted gerbera plants. Each isolate of F. oxysporum was grown in shake culture (90 rpm) for 10 days on casein hydrolysate at 25°C with 12 h of fluorescent light per day. Healthy rooted 30-day-old plants (cv. Jaska), were inoculated by dipping roots into a conidial suspension (5 × 107 conidia/ml) in one of the three test isolates of F. oxysporum. Plants were transplanted (1 plant per pot) into pots (3.5 liter vol.) containing rockwool-based substrate. Noninoculated plants served as control treatments. Plants (15 per treatment) were grown in a glasshouse at an average day temperature of 30°C and night temperature of 24°C (minimum of 22°C and maximum of 41°C). Wilt symptoms and vascular discoloration in the roots, crown, and veins developed within 30 days on each inoculated plant, while noninoculated plants remained healthy. F. oxysporum was consistently reisolated from infected plants. The pathogenicity test was conducted twice. A wilt of gerbera was described in the Netherlands in 1952 (1) but its presence was not confirmed in further observations (4). Gerbera wilt was recently reported in Italy (2) and identified as F. oxysporum f. sp. chrysanthemi (A. Garibaldi, personal communication). Currently, the wilt of gerbera in Spain is limited to a few farms and a very limited percent (2 to 3%) of plants. References: (1) J. Arx and J. A. von Tijdschr. PlZiekt. 58:5, 1952. (2) A. Garibaldi et al. Plant Dis. 88:311, 2004. (3) H. Komada. Rev. Plant Prot. Res. 8:114, 1975. (4) G. Scholten. Neth. J. Plant Pathol. 76:212, 1970.

scholarly journals First Report of Fusarium Wilt of Chicory (Cichorium intybus) Caused by Fusarium oxysporum in Italy

Plant Disease ◽  
2011 ◽  
Vol 95 (4) ◽  
pp. 496-496 ◽  
Author(s):  
A. Garibaldi ◽  
G. Gilardi ◽  
A. Poli ◽  
M. L. Gullino
Keyword(s):  
Fusarium Oxysporum ◽  
Vascular Tissue ◽  
Vascular System ◽  
Fusarium Species ◽  
Apical Cell ◽  
Selective Medium ◽  
Cichorium Intybus ◽  
Pathogenicity Test ◽  
First Report ◽  
Sequence Identity

In the summer of 2009, a wilt of chicory was observed on 25 to 30% of 30-day-old Cichorium intybus L. cv. Clio plants grown outdoors on a commercial farm in Piedmont (northern Italy). Affected plants were chlorotic and stunted with poorly developed root systems compared with healthy plants. Black streaks were observed in the stem and proximal part of the leaf vascular system in wilted plants. Fusarium oxysporum Schltdl. was isolated from symptomatic vascular tissue on a Fusarium-selective medium (1) from 80% of samples. Grown on potato dextrose agar (PDA) for 4 days at 23°C, the colonies, initially white and later pale pink, produced hyaline microconidia that were oval-elliptical and cylindrical in shape measuring 5.6 to 14.9 (average 10.2) × 2.1 to 4.5 (3.0) μm, borne on short monophialides measuring 8.2 to 16.1 (average 13.2) × 2.1 to 4.2 (3.3) μm. Macroconidia were slightly curved, three-septate, with a slightly hooked apical cell and a foot-shaped basal cell measuring 24.9 to 41.6 (average 32.2) × 3.2 to 5.2 (4.3) μm. Chlamydospores were both terminally and intercalary, solitary but also in short chains (2 to 4 elements) measuring 21.1 to 41.0 (average 27.2) μm (2). The internal transcribed spacer (ITS) rDNA region was amplified using the primers ITS1/ITS4 and sequenced. BLASTn analysis of the 527-bp amplicon (GenBank Accession No. HQ644423) obtained had 98% sequence identity with F. oxysporum (GenBank Accession No. FJ605247). The translation elongation factor-1α (EF-1α) gene was amplified using primers EF-1/EF-2 and sequenced (GenBank Accession No. GU564259). The 663-bp fragment had 99% sequence identity with F. oxysporum (GenBank Accession Nos. EU313540, EU313539, and DQ837696). Pathogenicity tests were conducted on 15-day-old chicory plants from two cultivars (Clio and Katia). Thirty-five plants per cultivar were inoculated by dipping their roots in a 1 × 106 CFU/ml suspension of isolate FusCic45B recovered from wilted chicory. Inoculated and noninoculated plants were transplanted into five pots filled with 10 liters of steamed mix (peat/perlite/sand, 60:20:20 vol/vol) and were maintained in a glasshouse at 25 to 27°C. Wilt symptoms and vascular discoloration of the roots, crown, and veins developed 15 days after inoculation on all inoculated plants. Plants of cv. Clio were more susceptible. F. oxysporum was always reisolated from infected plants using the Fusarium-selective medium. All noninoculated plants remained healthy. The pathogenicity test was conducted twice. To our knowledge, this is the first report of wilt caused by F. oxysporum on chicory, C. intybus, in Italy as well as worldwide. References: (1) H. Komada. Rev. Plant Prot. Res. 8:114, 1975. (2) E. Nelson et al. Fusarium Species: An Illustrated Manual for Identification. The Pennsylvania State University Press, University Park, 1983.

scholarly journals Fusarium Wilt of Gerbera Caused by a Fusarium sp. in Brazil

Plant Disease ◽  
2008 ◽  
Vol 92 (4) ◽  
pp. 655-655 ◽  
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
M. Shiniti Uchimura ◽  
M. L. Gullino
Keyword(s):  
Vascular Tissue ◽  
Vascular System ◽  
Casein Hydrolysate ◽  
Chrysanthemum Morifolium ◽  
Selective Medium ◽  
Fluorescent Light ◽  
Pathogenicity Test ◽  
Conidial Suspension ◽  
Italian Isolate ◽  
Fusarium Sp

In 2006, gerbera (Gerbera jamesonii) plants, cvs. Basic, Xena, and Olimpia grown for cut flower production in two greenhouse farms in the region of Guarapuava, Paraná, Brazil, exhibited symptoms of a wilt disease. Affected plants (approximately 20, 60, and 50% on cvs. Basic, Xena, and Olimpia, respectively) were stunted and developed yellow leaves unilaterally with initially brown and eventually black streaks in the vascular system. The first symptoms occurred 2 months after transplanting during the hottest period of the summer with an average air temperature of 27°C. Vascular streaks in the yellow leaves were continuous with a brown discoloration in the vascular system of the crown and upper taproot. Occasionally, the leaves of affected plants turned red. A Fusarium sp. was consistently and readily isolated onto a Fusarium-selective medium from symptomatic vascular tissue sampled from the crown of infected plants. Colonies were identified as Fusarium oxysporum on the basis of colony and conidia morphology (1) after subculturing on potato dextrose agar. Since F. oxysporum f. sp. chrysanthemi has been previously reported on Chrysanthemum morifolium, Argyranthemum frutescens, and gerbera (4), pathogenicity tests were carried out by using one monoconidial isolate obtained from wilted plants and one Italian isolate (F. oxysporum f. sp. chrysanthemi MASS 6). The isolates of F. oxysporum were grown in casein hydrolysate in shake culture (90 rpm) for 10 days at 25°C with 12 h of fluorescent light per day. Healthy rooted plants of 30-, 20-, and 45-day-old C. morifolium (cv. Captiva), A. frutescens (cv. Stella 2000), and gerbera (cvs. Jaska, Dalma, and Excellence), respectively, were inoculated by separately dipping roots into a conidial suspension (5 × 107 conidia/ml) of the two isolates of F. oxysporum. Plants were transplanted (one plant per pot) into pots (3.5 liter vol). Noninoculated plants served as control treatments. Plants (15 per treatment) were grown in a glasshouse at an average day temperature of 32°C and night temperature of 23°C (minimum 21°C and maximum 43°C). Wilt symptoms and discoloration of the vascular system in roots, crown, and petioles developed within 29 days on C. morifolium, 26 days on A. frutescens, and 14 days on gerbera. Noninoculated plants remained healthy. F. oxysporum was consistently reisolated from infected plants. The pathogenicity test was carried out twice. Gerbera wilt caused by F. oxysporum f. sp. chrysanthemi was recently reported in Italy (2) and Spain (3). Currently, the wilt of gerbera in the area of Paraná is limited to two farms. To our knowledge, this is the first report of the disease in Brazil as well as in South America. References: (1) C. Booth. Fusarium. CMI, Kew, UK, 1977. (2) A. Garibaldi et al. Plant Dis. 88:311, 2004. (3) A. Garibaldi et al. Plant Dis. 91:638, 2007. (4) A. Minuto et al. J. Phytopathol. 155:373, 2007.

scholarly journals First Report of Fusarium oxysporum Causing Vascular Wilt of Lamb's Lettuce (Valerianella olitoria) in Italy

Plant Disease ◽  
2004 ◽  
Vol 88 (1) ◽  
pp. 83-83 ◽  
Author(s):  
A. Garibaldi ◽  
G. Gilardi ◽  
M. L. Gullino
Keyword(s):  
Fusarium Oxysporum ◽  
Vascular Tissue ◽  
Selective Medium ◽  
Northern Italy ◽  
Growth Chamber ◽  
Pathogenicity Test ◽  
Vascular Wilt ◽  
First Report ◽  
Forma Specialis ◽  
Vascular Discoloration

Lamb's lettuce (Valerianella olitoria), also known as corn salad, is increasingly grown in Italy and used primarily in the preparation of mixed processed salad. In the summer of 2003, plants of lamb's lettuce cvs. Trophy and Palmares exhibiting wilt symptoms were observed in several commercial greenhouses near Bergamo in northern Italy. Wilted 30-day-old plants were observed first during the month of June, at the time of thinning when temperatures ranged between 28 and 35°C. Disease was generally uniform in the greenhouses and 30 to 50% of the plants were affected. Vascular tissue of affected seedlings appeared red or brown but later turned brown or black. Affected plants were stunted and developed yellowed leaves. Vascular discoloration was continuous from the upper taproot through the crown to the leaf. Fusarium oxysporum was consistently isolated from symptomatic vascular tissue onto a Fusarium-selective medium (1). Seeds of the same cultivars (Trophy and Palmares) affected by the wilt in the field were artificially inoculated by dipping them for 15 min into spore suspensions (1 × 106 conidia per ml) of three isolates of F. oxysporum obtained from infected plants. Noninoculated seeds served as control treatments. Forty seeds per treatment were sown in pots (1-liter volume) containing steam-sterilized soil and maintained at 25°C in a growth chamber programmed for 12 hours of light per day. Wilt symptoms developed on both cultivars 20 days after seeding, and F. oxysporum was consistently reisolated from infected plants. The plants obtained from noninoculated seeds remained healthy. The pathogenicity test was carried out twice with similar results. To our knowledge, this is the first report of F. oxysporum causing vascular wilt of lamb's lettuce and may warrant a new forma specialis designation. Reference: (1) H. Komada. Rev. Plant Prot. Res. 8:114, 1975.

scholarly journals First Report of Fusarium Wilt of Endive (Cichorium endivia) Caused by Fusarium oxysporum in Italy

Plant Disease ◽  
2009 ◽  
Vol 93 (10) ◽  
pp. 1078-1078 ◽  
Author(s):  
A. Garibaldi ◽  
G. Gilardi ◽  
M. Troisi ◽  
M. L. Gullino
Keyword(s):  
Fusarium Oxysporum ◽  
Vascular Tissue ◽  
Vascular System ◽  
Elongation Factor ◽  
Intergenic Spacer ◽  
Proximal Part ◽  
Selective Medium ◽  
Pathogenicity Test ◽  
First Report ◽  
Cichorium Endivia

In the summer of 2007, a wilt of endive (Cichorium endivia) cv. Myrna plants was observed on several commercial farms near Alessandria in northern Italy. Approximately 40% of the plants on each farm were symptomatic. Affected plants were stunted and yellow and their root systems were poorly developed. Basal leaves eventually wilted. Black streaks were observed in the proximal part of the leaf vascular system. Fusarium oxysporum was consistently isolated from symptomatic vascular tissue on a Fusarium-selective medium (1). To confirm identification of the pathogen, the translation elongation factor 1α and the ribosomal DNA intergenic spacer (IGS) region were partially sequenced (2). Genomic DNA was extracted from mycelia growing on potato dextrose agar. Amplification of the EF-1α region generated a sequence of 648 bp; the IGS amplicon was 2,500 bp. The EF-1α sequence (GenBank Accession No GQ398152) was 99% similar to the sequence of a F. oxysporum strain isolated from soil and a strain pathogenic on cotton plants (GenBank Accession No. EU246574). The IGS sequence (GenBank Accession No GQ398153) was 97% similar to the sequence of a F. oxysporum strain (GenBank Accession No. EF661647). Pathogenicity tests were conducted on 15-day-old endive plants (cv. Myrna). Ten plants were inoculated by dipping their roots in a 1 × 106 CFU/ml suspension of one of the isolates recovered from a wilted endive plant. Inoculated and noninoculated plants were transplanted into pots filled with steamed soil and maintained in a glasshouse at 23 to 28°C. Wilt symptoms and vascular discoloration of the roots, crown, and veins developed 60 days after inoculation. F. oxysporum was consistently reisolated from infected plants. Noninoculated plants remained healthy. The pathogenicity test was conducted twice. To our knowledge, this is the first report of wilt caused by F. oxysporum on endive in Italy. References: (1) H. Komada. Rev. Plant Prot. Res. 8:114, 1975. (2) G. Mbofung et al. Phytopathology 97:87, 2007.

scholarly journals First Report of Fusarium oxysporum on Eruca vesicaria and Diplotaxis spp. in Europe

Plant Disease ◽  
2003 ◽  
Vol 87 (2) ◽  
pp. 201-201 ◽  
Author(s):  
A. Garibaldi ◽  
G. Gilardi ◽  
M. L. Gullino
Keyword(s):  
Fusarium Oxysporum ◽  
Vascular System ◽  
Selective Medium ◽  
Wild Plants ◽  
Pathogenicity Test ◽  
First Report ◽  
Vascular Tissues ◽  
Brown Discoloration ◽  
Diplotaxis Erucoides ◽  
Wild Rocket

Two types of rocket are available on the market in Italy: (i) Eruca vesicaria (synonym E. sativa) known as ruchetta or cultivated garden rocket; and (ii) several species of Diplotaxis (Diplotaxis erucoides, D. muralis, and D. tenuifolia), which are wild plants now widely cultivated. Rocket is increasingly used in the mediterranean cuisine as salad and or to decorate dishes. In spring 2002, plants of the cultivated (E. vesicaria) and wild (Diplotaxis spp.) rocket showing symptoms of a wilt disease were observed in several commercial plastic greenhouses near Bergamo, in northern Italy. Wilted plants were first observed during the spring and summer of 2001 when temperatures were between 26 and 35°C. In May 2002, symptoms were again observed in the same area, on the same farm as well as other farms. Although the distribution of the disease was generally uniform, symptoms were more severe in the central part of the greenhouses where temperatures were warmest (30 to 60% of plants were affected). Diseased plants were stunted and chlorotic with brown or black streaks in the vascular system. Vascular tissues of affected plants appeared red or brown. Vascular streaks in the chlorotic leaves extended from the crown and were continuous with a red-brown discoloration in the vascular system of the crown and upper taproot. Fusarium oxysporum was consistently and readily isolated from symptomatic vascular tissues when plated on a Fusarium-selective medium (2). Microconidia measured 8.8 × 3.0 µm. E. vesicaria and Diplotaxis spp. were grown in steam-sterilized soil, and 10 days after emergence they were artificially inoculated by root dipping in a spore suspension (1 × 105 CFU/ml) of three F. oxysporum strains collected from infected plants. Uninoculated plants served as control. Plants (60 per treatment) were grown at 25 to 28°C in growth chambers. Wilt symptoms developed on all plants 20 days after inoculation, and F. oxysporum was consistently reisolated from infected plants. The pathogenicity test was conducted twice. To our knowledge, this is the first report of F. oxysporum on cultivated rocket in Europe and the first on wild rocket (Diplotaxis spp.) in the world. A wilt of E. sativa attributed to F. oxysporum f. sp. erucae was previously reported in India in 1973 (1). Studies are being carried out to determine if the Italian isolates of F. oxysporum belong to the same formae speciales. References: (1) C. Chatterjee and J. N. Rai. Indian Phytopathol 28:309, 1973. (2) H. Komada. Rev. Plant Prot. Res. 8:114, 1975.

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