Occurrence of Colletotrichum acutatum, Causal Organism of Strawberry Anthracnose in Southwestern Spain

A wilting disease of strawberry (Fragaria × ananassa Duchesne ‘Oso Grande’) was observed in production fields in Huelva, southwestern Andalucía, Spain. Crowns of wilted plants developed a reddish brown, firm rot. Longitudinal sections of roots of diseased plants showed a black coloration of the cortex. Symptons also included blighting of flowers due to floral infection and rotting of green and ripening fruits. On the fruit, the round, firm sunken lesions were covered with masses of salmon-colored spores. Lesions on the leaves were round, ranged in diameter from 5 to 10 mm, and were light brown with purple edges. Infected tissues were surface disinfected in 20% sodium hypoclorite, blotted dry, and plated on water agar. Dishes were incubated at 25°C; hyphal tips made of fungi growing from lesions were transferred to potato dextrose agar (PDA) and incubated under cool-white fluorescent light at 25°C. One fungus was isolated consistently from lesions on different tissues. It was identified as Colletotrichum acutatum by morphological characteristics (2) and enzyme-linked immunosorbent assay (1). On PDA, the mycelium of the fungus was white to gray and covered with salmon spore masses. Colony diameters on PDA averaged 45 mm after 7 days at 25°C. Hyaline, aseptate conidia were cylindrical, fusiform, and intermediate in shape and averaged 12.8 × 4.2 μm in size. The fungus produced setae on infected fruit. Inoculations of strawberry cvs. Oso Grande and Chandler with conidial suspensions (106 conidia per ml) of C. acutatum produced lesions on the fruit, petioles, and crowns, and caused wilt. The pathogen was reisolated from lesions on the inoculated plants. This is the first report of C. acutatum causing strawberry anthracnose in Huelva. References: (1) T. A. Cooke et al. EPPO Bulletin 25:57, 1995. (2) B. C. Sutton. The Coelomycetes. CMI, Kew, England, 1980.

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First Report of Colletotrichum acutatum in Blueberry Plants in Spain

Plant Disease ◽

10.1094/pdis.2001.85.12.1285a ◽

2001 ◽

Vol 85 (12) ◽

pp. 1285-1285 ◽

Cited By ~ 3

Author(s):

C. Barrau ◽

B. de los Santos ◽

F. Romero

Keyword(s):

Pink Salmon ◽

Morphological Characteristics ◽

Vaccinium Corymbosum ◽

Fungal Species ◽

Colletotrichum Acutatum ◽

Enzyme Linked Immunosorbent Assay ◽

Conidial Suspension ◽

First Report ◽

Small Areas ◽

Leaf Tissues

An anthracnose disease was observed affecting leaves of high-bush blueberry plants (Vaccinium corymbosum L. ‘Sharpblue’) in small areas within two production fields in Huelva Province of Andalucía, in southwestern Spain. The first symptoms observed in late spring were circular, necrotic lesions, red to salmon in color, and ranging from 3 to 20 mm in diameter. Later, lesions became salmon colored in the center with a brilliant red halo. Fungal isolations were made from the lesions. Infected tissues were surface-disinfected in 1% sodium hypochlorite for 1 min, blotted dry on sterile filter paper, and plated on 2% water agar. The plates were incubated at 25°C for 5 to 10 days. Fungal colonies isolated from the tissues were transferred to potato dextrose yeast agar (PDYA). Only one fungal species was consistently isolated from affected leaf tissues and was identified as Colletotrichum acutatum J.H. Simmonds based on morphological characteristics (2) and enzyme-linked immunosorbent assay (1). Colonies of the fungus on PDYA showed a white-to-gray dense mycelium covered with salmon-colored spore masses. The reverse of the plates was a pink-salmon color. Colony diameter on PDYA averaged 50 mm after 7 days at 25°C. Conidia were hyaline, aseptate, fusiform to cylindrical, and 12.5 × 3.2 μm. Inoculation of leaves and fruits of blueberry cv. Misty with a conidial suspension (106 conidia per ml) of C. acutatum produced lesions on the leaves and fruits similar to those observed on diseased plants in the field. The pathogen was isolated from lesions on inoculated plants. To our knowledge, this is the first report of C. acutatum in high-bush blueberry plants in Spain. References: (1) T. A. Cooke et al. EPPO Bull. 25:57, 1995. (2) B. C. Sutton. The Coelomycetes. CMI, Kew, England, 1980.

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First Report of Fusarium Wilt Caused by Fusarium oxysporum on Strawberry in Spain

Plant Disease ◽

10.1094/pdis-93-3-0323b ◽

2009 ◽

Vol 93 (3) ◽

pp. 323-323 ◽

Cited By ~ 22

Author(s):

F. T. Arroyo ◽

Y. Llergo ◽

A. Aguado ◽

F. Romero

Keyword(s):

Fusarium Oxysporum ◽

Fusarium Wilt ◽

Potato Dextrose Agar ◽

Fluorescent Light ◽

Pathogenicity Test ◽

Conidial Suspension ◽

Soilless Culture ◽

Fragaria Ananassa ◽

Pcr Assay ◽

First Report

In the spring of 2007, wilted and dead strawberry plants (Fragaria × ananassa Duch. cvs. Camarosa and Ventana) were observed in a soilless culture system in Huelva, southwestern Spain. Approximately 8% of the plants in the field died. Isolations from necrotic crowns and roots and necrotic flowers were made on potato dextrose agar after disinfestation in 0.6% NaOCl for 30 s. Colonies with light purple mycelia and beige or orange reverse colony colors developed after 9 days of incubation at 25°C. Colonies produced abundant microconidia, macroconidia, and chlamydospores. Microconidia were hyaline and oval-ellipsoid to cylindrical (5.9 to 9.2 × 2.1 to 3.4 μm). Macroconidia were 3 to 5 septate and fusoid-subulate with a pedicellate base (28.8 to 37.3 × 3.2 to 4.3 μm). Morphology and growth matched descriptions of Fusarium oxysporum Schlechtend emend. Snyder & Hansen (2). A PCR assay for amplification of r-DNA using primers PFO2 and PFO3 established the identity of the isolate as F. oxysporum (1). To confirm the pathogenicity of the fungus, roots of 30-day-old strawberry cvs. Camarosa and Ventana (20 plants each) were inoculated by dipping the roots into a conidial suspension (107 conidia per ml) for 15 min. The inoculated plants were transplanted into plastic pots containing sterilized peat and maintained at 25°C and 100% relative humidity in a growth chamber with a daily 12-h photoperiod of fluorescent light. The pathogenicity test was conducted twice. Within 30 days, all inoculated plants developed wilt symptoms similar to that observed in the field and eventually 75% of the plants died. No symptoms were observed on plants dipped in distilled water. The fungus was successfully reisolated from crowns, roots, and necrotic flowers, fulfilling Koch's postulates. To our knowledge, this is the first report of the occurrence of Fusarium wilt caused by F. oxysporum on strawberry plants in Spain. References: (1) V. Edel et al. Mycol. Res. 104:518, 2000. (2) W. C. Snyder and H. N. Hansen. Am. J. Bot. 27:64, 1940.

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First Report of Colletotrichum gloeosporioides on Strawberry in Northwestern Argentina

Plant Disease ◽

10.1094/pdis.2000.84.5.595c ◽

2000 ◽

Vol 84 (5) ◽

pp. 595-595 ◽

Cited By ~ 4

Author(s):

M. E. Mónaco ◽

S. M. Salazar ◽

A. Aprea ◽

J. C. Díaz Ricci ◽

J. C. Zembo ◽

...

Keyword(s):

White Light ◽

Colletotrichum Gloeosporioides ◽

Morphological Characteristics ◽

Fragaria Ananassa ◽

Disease Symptoms ◽

Northwestern Argentina ◽

First Report ◽

Spray Inoculation ◽

Strawberry Anthracnose ◽

Pathogenicity Tests

Colletotrichum gloeosporioides was isolated from symptomatic strawberry (Fragaria × ananassa Duch. ‘Chandler’) growing in Lules (Tucumán, Argentina). Isolates were characterized based on several criteria. Potato dextrose agar (PDA) was used to evaluate cultural and morphological characteristics of the isolates. After 10 days on PDA at 28°C under continuous white light, colonies showed abundant aerial, cottony white to pale beige growth, with orange asexual fruiting bodies in older colonies. Isolates displayed cylindrical conidia, rounded at both ends, averaging 10.4 × 3.9 µm (length by width). A sexual phase (perithecia) was observed in all isolates in 2-month-old cultures on PDA at 28°C under continuous white light. Pathogenicity tests were conducted with healthy plants of cvs. Pájaro and Chandler. Spray inoculation with conidial suspensions (106 conidia per ml) resulted in disease symptoms (petiole and crown lesions with wilting of crown-infected plants) 7 days after inoculation. Infection progressed at a higher rate in Pájaro than in Chandler. Reisolations from infected strawberry lesions yielded isolates with characteristics identical to the isolate used to inoculate the host. Based on morphological and cultural characteristics, isolates were identified as C. gloeosporioides Penz. & Sacc. (teleomorph Glomerella cingulata Spauld & H. Schenk) (1). This is the first report of C. gloeosporioides causing strawberry anthracnose in northwestern Argentina. Reference: (1) P. S. Gunnell and W. D. Gubler. Mycol. 84:157, 1992.

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First Report of Anthracnose Fruit Rot of Strawberry Caused by Colletotrichum acutatum in China

Plant Disease ◽

10.1094/pd-90-1460a ◽

2006 ◽

Vol 90 (11) ◽

pp. 1460-1460 ◽

Cited By ~ 2

Author(s):

F. M. Dai ◽

X. J. Ren ◽

J. P. Lu

Keyword(s):

Relative Humidity ◽

Fruit Rot ◽

Colletotrichum Acutatum ◽

Fluorescent Light ◽

Fragaria Ananassa ◽

Strawberry Fruit ◽

First Report ◽

Colony Color ◽

Ascigerous Stage ◽

Germ Tubes

In 2004, fruits showing dark and sunken necrotic lesions were observed on strawberries (Fragaria × ananassa Duch. cv. Mei No. 3) in a field in Shanghai, China. All isolates obtained from the infected fruits easily produced orange spore masses and developed orange colonies with orange reverse colony color; none formed setae or the ascigerous stage in culture or on the host. The conidia were hyaline, straight and fusiform, 8 to 16 × 2.5 to 4 μm, and produced melanized, ellipsoid, ball- or pear-shaped appressoria at the end of germ tubes. These isolates were similar to those described for Colletotrichum acutatum J. H. Simmonds. To confirm pathogenicity of the isolate, inoculum suspension with 4 × 106 conidia/ml was sprayed onto 10 fruiting strawberry plants until runoff. The inoculated plants were maintained at 25°C and 100% relative humidity in a growth chamber with a 12-h period of fluorescent light daily. Plants inoculated with sterilized water were controls. After 3 days, dark brown lesions appeared in the leaves, petioles, and fruits of all inoculated plants. The symptoms were similar to those observed on the strawberry fruit from which the isolate was originally isolated. The pathogen was consistently reisolated from the symptomatic fruit. No symptoms were observed on the control plants. To our knowledge, this is the first report of C. acutatum as the casual agent of anthracnose fruit rot of strawberry in China.

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First Report of Anthracnose Fruit Rot of Strawberry Caused by Colletotrichum acutatum in Montenegro

Plant Disease ◽

10.1094/pdis-02-12-0108-pdn ◽

2012 ◽

Vol 96 (7) ◽

pp. 1066-1066 ◽

Cited By ~ 1

Author(s):

J. Latinovic ◽

N. Latinovic ◽

J. Tiodorovic ◽

A. Odalovic

Keyword(s):

Morphological Characteristics ◽

Its Region ◽

Fruit Rot ◽

Colletotrichum Acutatum ◽

Pathogenicity Test ◽

Centraalbureau Voor ◽

First Report ◽

Strawberry Anthracnose ◽

Production Area ◽

Ascigerous Stage

Strawberries (Fragaria × ananassa) in Montenegro have become an increasingly important economic crop in recent years. During May 2011, severe fruit damage in strawberry cv. Clery was observed in two fields in the Podgorica region. Fruit symptoms were typical for strawberry anthracnose: sunken, dark brown to black circular lesions appeared on maturing fruits. However, no stem, crown, or foliar symptoms were observed. Under wet conditions, orange masses of conidia were produced in acervuli in the center of lesions. Conidia were hyaline, aseptate, cylindrical, with pointed ends, measuring 9.8 to 17.2 (mean 14.3) × 2.5 to 6.1 (mean 4.4) μm. Colonies on potato dextrose agar (PDA) were initially white, then turned gray as conidia formed in orange to salmon pink masses around the center of the culture. Setae or an ascigerous stage were never observed in culture or on the host. Koch's postulates were fulfilled by inoculating ripe and unripe asymptomatic fruits (20 of each, removed from strawberry plants cv. Clery) with the isolated fungus. Fruits were sprayinoculated (106 conidia/ml). An equal number of noninoculated fruits were used as a control. After incubation time of 2 to 3 days at 25°C in a moist chamber, symptoms appeared on inoculated ripe fruits. On unripe fruits, the lesions developed only 3 to 4 days after the inoculation. No symptoms were found on control fruits. The fungus was reisolated from fruits, after which typical morphological characteristics developed in culture as described above. On the basis of the symptoms, the morphological and cultural characteristics of the fungus, and the pathogenicity test, the disease was identified as strawberry anthracnose caused by Colletotrichum acutatum, which is in accordance with previous reports (1,2,3,4). The isolate was submitted to the Centraalbureau voor Schimmelcultures in the Netherlands (CBS 131813). The internal transcribed spacer (ITS) region of the fungal DNA was amplified with ITS1F and ITS4 primers, sequenced, and submitted to NCBI GenBank (Accession No. JQ424934). BLASTn searches of GenBank using the ITS sequence revealed 99% similarity with database sequences of C. acutatum. Since the pathogen was found in the main Montenegrin strawberry production area, it poses a threat to strawberry production in Montenegro. To our knowledge, this is the first report of anthracnose fruit rot of strawberry in Montenegro. References: (1) S. G. Bobev et al. Plant Dis. 86:1178, 2002. (2) F. M. Dai et al. Plant Dis. 90:1460, 2006. (3) U. Nilsson et al. Plant Dis. 89:1242, 2005. (4) A. Stensvand et al. Plant Dis. 85:558, 2001.

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First Report of Anthracnose on Fruits of Duchesnea indica Caused by Colletotrichum acutatum in Northwestern Argentina

Plant Disease ◽

10.1094/pdis-05-11-0368-pdn ◽

2012 ◽

Vol 96 (5) ◽

pp. 765-765

Author(s):

E. B. Sir ◽

M. E. Arias ◽

J. Racedo ◽

A. Castagnaro ◽

J. C. Díaz Ricci

Keyword(s):

White Light ◽

Morphological Characteristics ◽

Pcr Amplification ◽

Aerial Mycelium ◽

Colletotrichum Acutatum ◽

Fragaria Ananassa ◽

Northwestern Argentina ◽

First Report ◽

Duchesnea Indica ◽

Species Specific

Duchesnea indica (Andrews) Focke, a cosmopolitan wild species related to the cultivated strawberry that is widely distributed in northwestern Argentina, grows in close proximity to strawberry crops and has proven to be almost immune to Colletotrichum spp. isolated from diseased strawberry plants (1), hence it has never been considered a phytopathological risk. During a field survey of “La Heladera” (27°01′45″S, 65°39′20″W), Tafí del Valle (Tucumán, Argentina) from November 2009 to November 2010, a genotype of D. indica showing fruits with dark brown, necrotic, irregular, circular lesions of 5 to 20 mm in diameter were collected. Setose acervuli were observed on the center of the fruit lesions. Pathogens were obtained from 10 diseased fruit collected at random, and four fungal isolates were isolated per fruit on potato dextrose agar (PDA). To reduce the number of samples for evaluation, two isolates per fruit that were exhibiting stable but distinctive morphological features were chosen to continue the studies. Isolates were characterized by morphological, molecular, and phytopathological criteria. After 10 days of incubation on PDA medium at 28°C with continuous white light, colonies exhibited a gray, aerial mycelium, whereas the reverse of the colony is a pale maroon with a radial, pale salmon color. Masses of salmon-colored conidia formed in the center of the colonies. Conidia were hyaline, one celled, fusiform, tapered to a point at both ends, and measured 14.8 to 17.3 × 4.5 to 7.4 μm (n = 100). Setae were scarce and sclerotia were absent. All morphological characteristics that were observed indicated that the isolates were C. acutatum (3). To fulfill Koch's postulates and verify the pathogenicity on commercial varieties of strawberry, six healthy plants of D. indica and Fragaria × ananassa cv. Camarosa with mature fruits were used to test each isolate. Four plants were spray inoculated with conidial suspensions of the virulent isolates (1.5 × 106 conidia/ml) and two with sterile distilled water as controls. Both treatments were maintained under white light (2,000 lux, 12 h per day) at 28°C and 70% relative humidity. Nine days after the inoculation, dark brown lesions and salmon-colored masses of conidia were observed only in inoculated fruits of both genotypes. The fungus isolated from diseased fruits and the conidia that were produced were identical to the isolates used to inoculate the plants. To confirm pathogen identity, PCR amplification with the species-specific pair of primer CaInt2/ITS4 (4) were carried out using fungal total DNA from the original isolates and isolates obtained from inoculated fruits. An amplification product of approximately 490 bp, which is specific for C. acutatum, was observed in all DNA samples (4). Although C. acutatum has already been reported in Fragaria × ananassa in Argentina (2), to our knowledge, this is the first report of C. acutaum causing anthracnose in D. indica species. This result is relevant since this species grows close to strawberry fields and can be an alternative host and potential vector of the anthracnose disease agent. References: (1) M. E. Arias. Frutillas Silvestres y Especies Relacionadas con la Cultivada. EDUNT, Argentina, 2007. (2) C. J. Ramallo et al. Plant Dis. 84:706. 2000. (3) B. J. Smith and L. L. Black. Plant Dis. 74:69, 1990. (4) S. Sreenivasaprasad et al. Plant Pathol. 45:650, 1996.

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First Report of Colletotrichum acutatum in Strawberry in Norway

Plant Disease ◽

10.1094/pdis.2001.85.5.558c ◽

2001 ◽

Vol 85 (5) ◽

pp. 558-558 ◽

Cited By ~ 3

Author(s):

A. Stensvand ◽

G. M. Strømeng ◽

R. Langnes ◽

L. G. Hjeljord ◽

A. Tronsmo

Keyword(s):

Growth Rate ◽

Morphological Characters ◽

Potato Dextrose Agar ◽

Colletotrichum Acutatum ◽

Conidial Suspension ◽

Centraalbureau Voor ◽

Crown Tissue ◽

Strawberry Anthracnose ◽

International Mycological Institute ◽

Unripe Fruits

Anthracnose caused by Colletotrichum acutatum J. H. Simmonds was detected in strawberry (Fragaria × ananassa Duch.) for the first time in Norway in 1999. Symptoms were found in greenhouse grown strawberries in the cultivar Korona. Symptoms were typical of strawberry anthracnose: sunken, brown, and firm lesions appeared on maturing fruits. Masses of conidia were produced in acervuli in the center of lesions. The fungus was isolated on acidified potato dextrose agar. Colonies grown on potato dextrose agar (PDA) were pale to mouse gray and became dark greenish to blackish in reverse. Conidia were formed in orange to salmon pink masses in the center of the culture. Conidia in cultures were 16.5 (13.8 to 18.8) × 4.5 (3.8 to 5) μm, and were hyaline, cylindrical, with pointed ends, and aseptate. Setae were never observed in culture or on fruits. The fungus did not form an ascigerous stage in culture. Mycelial growth rate at 25 to 26°C on PDA was 8.1 to 8.4 mm per day. Morphological characters and growth rate were in accordance with previous reports on C. acutatum (1,2). The isolated fungus was confirmed to be C. acutatum by both the International Mycological Institute, Egham, England, and Centraalbureau voor Schimmelcultures, Baarn, the Netherlands. Koch's postulates were fulfilled by inoculating ripe and unripe fruits on strawberry plants with the isolated fungus. Fruits were either sprayed with a conidial suspension (106 conidia per ml) or slightly wounded with a needle that had been dipped in a conidial mass from a pure culture of C. acutatum. Symptoms appeared after 4 days at 20°C, and after 5 days, brown, sunken, circular lesions reached a size of 1 cm in diameter on wounded, ripe fruits. In unripe fruits the lesions developed more slowly, and in unwounded fruits sprayed with a conidial suspension, large, irregular spots developed. Leaves were inoculated by placing a small block of agar at the base of petioles on intact strawberry plants. The tissue underneath the agar was either unwounded or slightly wounded with a needle. After 20 days (at 20 to 25°C) some necrosis developed on both unwounded and wounded petioles. No symptoms were observed in the crown tissue where the inoculated petioles were attached. The fungus was readily reisolated from both fruits and petioles, after which typical morphological characters developed in culture as described above. References: (1) P. S. Gunnell and W. D. Gubler. Mycologia 84:157, 1992. (2) B. J. Smith and L. L. Black. Plant Dis. 74:69, 1990.

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CHARACTERISTIC OF OVARIAN AND ESTRADIOL CONCENTRATIONS IN THE FOLLICULAR FLUID OF SLAUGHTERED ACEH CATTLE

Jurnal Kedokteran Hewan - Indonesian Journal of Veterinary Sciences ◽

10.21157/j.ked.hewan.v13i4.12890 ◽

2020 ◽

Vol 13 (4) ◽

Author(s):

Mulyadi Adam ◽

Gholib Gholib ◽

Hafizuddin Hafizuddin ◽

Rumi Sahara Zamzami ◽

Muhammad Bahi

Keyword(s):

In Vitro Fertilization ◽

Immunosorbent Assay ◽

Follicular Fluid ◽

Morphological Characteristic ◽

In Vitro Maturation ◽

Morphological Characteristics ◽

Enzyme Linked Immunosorbent Assay ◽

Vitro Fertilization ◽

Banda Aceh

The objective of this study was to characterize the morphology of ovary from slaughtered Aceh cow and measuring the concentration of estradiol in the follicular fluid to examine the potential utilizing for in-vitro fertilization (IVF) development in Aceh cattle. In total, 30 pairs of ovaries were collected from 30 Aceh cattle slaughtered at Banda Aceh abattoir. Morphological characteristics of ovaries observed were the size of ovaries, weight of ovaries, number of follicles, the diameter of follicles, corpus luteal (CL), and volume of follicular fluid. The follicular fluid was aspirated using a disposable syringe and analyzed the estradiol concentrations using enzyme-linked immunosorbent assay (ELISA). The follicles were grouped into 3 categories based on the diameter (Ø) of follicles: small follicles (Ø 1 - 5 mm), medium follicles (Ø 5 - 8 mm), and large follicles (Ø 8 mm). The morphological characteristic of ovaries varied between right and left ovaries in which right ovaries showed bigger size and weight compared to the left ovaries (P0.05), whereas the number of follicles and follicular fluid did not significantly different (P0.05). The concentrations of estradiol in follicular fluid of large and medium follicles were significantly higher compared to small follicles (P0.05), whereas the concentration of estradiol between large and medium follicles, did not significant different (P0.05). In conclusion, the follicles from abattoir can be used as potential oocytes resources to support IVF development for Aceh cattle in the future. The follicular fluid provided from these follicles can be an alternative for in vitro maturation media of oocytes due to containing high estradiol concentrations.

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First Report of Colletotrichum acutatum on Strawberry in Finland

Plant Disease ◽

10.1094/pdis.2001.85.8.923a ◽

2001 ◽

Vol 85 (8) ◽

pp. 923-923 ◽

Cited By ~ 3

Author(s):

P. Parikka ◽

M. Kokkola

Keyword(s):

Black Spot ◽

Fruit Rot ◽

Colletotrichum Acutatum ◽

Enzyme Linked Immunosorbent Assay ◽

Science Laboratory ◽

Fragaria Ananassa ◽

Salmon Pink ◽

Small Fruit ◽

First Time ◽

Eastern Finland

Strawberry (Fragaria × ananassa) is the most important small fruit crop in Finland. The quarantined pest Colletotrichum acutatum was detected for the first time on strawberry in August 2000, in Eastern Finland. Waiting-bed plants of cultivar Elsanta had symptoms typical of anthracnose rot (black spot) on the fruit, and small black lesions were seen on stolons. The rainy, warm, and humid weather of the summer favored the development and spread of the disease. C. acutatum was isolated from lesions on the fruit. Abundant sporulation was observed on lesions, and the fungus was readily isolated on potato dextrose agar (PDA) from surface-sterilized fruit pieces. Spores (11.5 to 19.8 × 3.3 to 4.0 μm) were acute at both ends, and acervuli with salmon pink spore masses matched the descriptions of C. acutatum (1). At first, the colonies were white and later became ash gray. The growth rate of the fungus was 8.0 to 8.8 mm per day, at 27°C. The identification was confirmed with enzyme-linked immunosorbent assay at the Central Science Laboratory, York, U.K. In order to fulfill Koch's postulates, young potted strawberry plants were inoculated by misting with a suspension of 10.4 × 106 conidia per ml of C. acutatum. Healthy runner plants of micropropagated cultivars Bounty, Cudaruska, Jonsok, Korona, and Oka (10 plants of each cultivar) were inoculated and incubated for 3 days, at 100% relative humidity. After 3 weeks at 20 to 21°C and 16 h of light per day, dark, elongated lesions measuring 2 to 15 mm were observed on the stolons. All tested cultivars developed symptoms on stolons and petioles, but no crown infections were detected. Flowering and fruit-bearing plants of cultivars Honeoye, Sara, and Senga Sengana were similarly inoculated and incubated. The first symptoms of fruit rot were detected 5 days after inoculation on the ripening fruit of Honeoye. Less severe fruit rot was seen on the fruit of Senga Sengana and the Fragaria vescana cultivar Sara. Salmon pink sporodochia developed on infected fruit, stolons, and leaves, within 5 days on moist filter paper, and C. acutatum was isolated on PDA. No other pathogens were present. Because C. acutatum is a quarantined pest in Finland, all strawberry plants of the infected lot on this particular farm were destroyed and future use of the field will be restricted. Reference: (1) C. M. Howard et al. 1992. Plant Dis. 76:976–981.

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First Report of Anthracnose Fruit Rot Caused by Colletotrichum acutatum on Strawberry in Denmark

Plant Disease ◽

10.1094/pd-89-0432b ◽

2005 ◽

Vol 89 (4) ◽

pp. 432-432 ◽

Cited By ~ 6

Author(s):

T. Sundelin ◽

M. Schiller ◽

M. Lübeck ◽

D. F. Jensen ◽

K. Paaske ◽

...

Keyword(s):

Morphological Characteristics ◽

Aerial Mycelium ◽

Fruit Rot ◽

Colletotrichum Acutatum ◽

Enzyme Linked Immunosorbent Assay ◽

First Report ◽

Small Fruit ◽

Quarantine Pathogen ◽

Species Specific ◽

Pointed End

Strawberry (Fragaria × ananassa) is the most important small fruit crop in Denmark. The quarantine pathogen Colletotrichum acutatum was detected for the first time in June 2000 in Denmark in a production field on the island of Falster. Strawberry plants of cv. Kimberly showed typical symptoms of anthracnose fruit rot. On mature fruits, brown-to-black lesions with spore masses that were orange to salmon in color were observed. Mummified berries were also observed. The fungus was isolated and identified on the basis of morphological characteristics, and identification was confirmed using enzyme-linked immunosorbent assay at the Central Science Laboratory, York, U.K. Species-specific polymerase chain reaction with the C. acutatum-specific primer pairs acut1/col2 (1) and CaInt2/ITS4 (3) also supported the identification. Additionally, the internal transcribed spacer regions, ITS1 and ITS2, of the ribosomal DNA were sequenced in both directions (GenBank Accession No. AY818361). Homology searches with this sequence using BLAST also confirmed the identity. Colonies grown on potato dextrose agar developed white-to-grey aerial mycelium with salmon-colored spore masses, and were beige to black on the reverse side. Conidia were 11.3 (7.3 to 16.6) μm × 3.9 (2.5 to 5.2) μm, hyaline, cylindrical with at least one pointed end, and aseptate. Mycelial growth rate was 8.4 mm per day at 25°C which is similar to earlier reports (2). Spray-inoculated (106 conidia per ml) strawberry fruits cv. Elsanta developed brown, sunken, irregular lesions with salmon-colored acervuli after 2 to 5 days at 25°C. Koch's postulates were fulfilled since the reisolated fungus from these lesions developed the same morphological characteristics as described above. To our knowledge, this is the first report of C. acutatum in Denmark. References: (1) P. V. Martinez-Culebras et al. J. Phytopathol. 151:135, 2003. (2) B. J. Smith et al. Plant Dis. 74:69, 1990. (3) S. Sreenivasaprasad et al. Plant Pathol. 45:650, 1996.

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