scholarly journals First Report of Anthracnose Caused by Colletotrichum acutatum on Persimmon Fruit in the United States

Plant Disease ◽  
2010 ◽  
Vol 94 (5) ◽  
pp. 634-634 ◽  
Author(s):  
S. M. Williamson ◽  
T. B. Sutton
Keyword(s):  
United States ◽  
Filter Paper ◽  
The United States ◽  
Grocery Store ◽  
Fruit Rot ◽  
Colletotrichum Acutatum ◽  
Diospyros Kaki ◽  
Japanese Persimmon ◽  
First Report ◽  
Persimmon Fruit

Persimmon trees are important for their fruit as well as their colorful fruit and foliage in the fall. Persimmon fruit (Japanese persimmon, Diospyros kaki cv. Fuyu) were collected in November 2008 from a tree in Windsor, NC, located in the Coastal Plain. Fruit were not symptomatic on the tree but developed dark lesions after harvest. Isolations from six fruit yielded seven isolates of Colletotrichum acutatum J. H. Simmonds. After incubation at 25°C under continuous light for 15 days on potato dextrose agar (PDA), all isolates had gray aerial mycelium, but the inverse sides of the plates of six isolates were maroon and one was beige. Masses of salmon-colored conidia were formed first in the center of the colonies, then were observed scattered across the colonies in older cultures. Conidia were hyaline, one-celled, elliptic with one or both ends pointed, and measured 8.1 to 16.3 × 3.1 to 5 μm. Setae and sclerotia were not observed. There were also dark structures measuring 1 to 10 mm that were partially embedded in the agar that contained conidia. Cultural and conidial characteristics of the isolates were similar to those of C. acutatum (3). PCR amplification was performed with the species-specific primer pair CaInt2/ITS4 (2) and genomic DNA from the original isolates and isolates obtained from inoculated fruit. An amplification product of approximately 490 bp, which is specific for C. acutatum, was observed. To fulfill Koch's postulates, persimmon fruit obtained from the grocery store were surface disinfested with 0.5% sodium hypochlorite and sterile filter paper disks dipped in conidial suspensions (1 × 105 conidia/ml) of two C. acutatum isolates (maroon and beige reverse) or sterile, deionized water were placed on the fruit. Three fruit were inoculated per treatment and the disks were placed on four locations on each fruit. Parafilm was wrapped around the diameter of the fruit to keep the filter paper disks moist and in place. Fruit were placed in moist chambers and incubated at 25°C. After 3 days, the Parafilm was removed and the fruit returned to the moist chambers. Small, dark lesions were observed on fruit inoculated with each isolate of C. acutatum when the filter paper disks were removed. Ten days after inoculation, dark lesions and acervuli with salmon-colored masses of conidia were observed on fruit inoculated with both isolates of C. acutatum and the fruit were soft. After 12 days, there were abundant masses of conidia and the inoculated areas were decayed. Control fruit remained firm and did not develop symptoms. Cultures obtained from the fruit and the conidia produced were typical of the isolates used to inoculate the fruit. C. acutatum has been reported to cause fruit rot on persimmon fruit in New Zealand (1). To our knowledge, this is the first report of C. acutatum on persimmon fruit in the United States. References: (1) R. Lardner et al. Mycol. Res. 103:275, 1999. (2) S. Sreenivasaprasad et al. Plant Pathol. 45:650, 1996. (3) B. C. Sutton. Page 523 in: Coelomycetes. Commonwealth Agricultural Bureaux, Great Britain. 1980.

scholarly journals First Report of Postharvest Fruit Rot in Persimmon Caused by Phacidiopycnis washingtonensis in Italy

Plant Disease ◽  
2010 ◽  
Vol 94 (6) ◽  
pp. 788-788 ◽  
Author(s):  
A. Garibaldi ◽  
D. Bertetti ◽  
M. T. Amatulli ◽  
M. L. Gullino
Keyword(s):  
United States ◽  
Its Region ◽  
The United States ◽  
Fruit Rot ◽  
Diospyros Kaki ◽  
Pathogenicity Test ◽  
Conidial Suspension ◽  
First Report ◽  
Pathogenicity Tests ◽  
Phacidiopycnis Washingtonensis

Persimmon (Diospyros kaki L.) is widely grown in Italy, the leading producer in Europe. In the fall of 2009, a previously unknown rot was observed on 3% of fruit stored at temperatures between 5 and 15°C in Torino Province (northern Italy). The decayed area was elliptical, firm, and appeared light brown to dark olive-green. It was surrounded by a soft margin. The internal decayed area appeared rotten, brown, and surrounded by bleached tissue. On the decayed tissue, black pycnidia that were partially immersed and up to 0.5 mm in diameter were observed. Light gray conidia produced in the pycnidia were unicellular, ovoid or lacriform, and measured 3.9 to 6.7 × 2.3 to 3.5 (average 5.0 × 2.9) μm. Fragments (approximately 2 mm) were taken from the margin of the internal diseased tissues, cultured on potato dextrose agar (PDA), and incubated at temperatures between 23 and 26°C under alternating light and darkness. Colonies of the fungus initially appeared ash colored and then turned to dark greenish gray. After 14 days of growth, pycnidia and conidia similar to those described on fruit were produced. The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS4/ITS6 and sequenced. BLAST analysis (1) of the 502-bp segment showed a 100% similarity with the sequence of Phacidiopycnis washingtonensis Xiao & J.D. Rogers (GenBank Accession No. AY608648). The nucleotide sequence has been assigned the GenBank Accession No. GU949537. Pathogenicity tests were performed by inoculating three persimmon fruits after surface disinfesting in 1% sodium hypochlorite and wounding. Mycelial disks (10 mm in diameter), obtained from PDA cultures of one strain were placed on wounds. Three control fruits were inoculated with plain PDA. Fruits were incubated at 10 ± 1°C. The first symptoms developed 6 days after the artificial inoculation. After 15 days, the rot was very evident and P. washingtonensis was consistently reisolated. Noninoculated fruit remained healthy. The pathogenicity test was performed twice. Since P. washingtonensis was first identified in the United States on decayed apples (2), ‘Fuji’, ‘Gala’, ‘Golden Delicious’, ‘Granny Smith’, ‘Red Chief’, and ‘Stark Delicious’, apple fruits also were artificially inoculated with a conidial suspension (1 × 106 CFU/ml) of the pathogen obtained from PDA cultures. For each cultivar, three surface-disinfested fruit were wounded and inoculated, while three others served as mock-inoculated (sterile water) controls. Fruits were stored at temperatures ranging from 10 to 15°C. First symptoms appeared after 7 days on all the inoculated apples. After 14 days, rot was evident on all fruit inoculated with the fungus, and P. washingtonensis was consistently reisolated. Controls remained symptomless. To our knowledge, this is the first report of the presence of P. washingtonensis on persimmon in Italy, as well as worldwide. The occurrence of postharvest fruit rot on apple caused by P. washingtonensis was recently described in the United States (3). In Italy, the economic importance of the disease on persimmon fruit is currently limited, although the pathogen could represent a risk for apple. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) Y. K. Kim and C. L. Xiao. Plant Dis. 90:1376, 2006. (3) C. L. Xiao et al. Mycologia 97:473, 2005.

scholarly journals First Report of Phytophthora syringae Causing Rot on Apples in Cold Storage in the United States

Plant Disease ◽  
2002 ◽  
Vol 86 (6) ◽  
pp. 693-693 ◽  
Author(s):  
R. A. Spotts ◽  
G. G. Grove
Keyword(s):  
United States ◽  
Cold Storage ◽  
The United States ◽  
River Valley ◽  
Fruit Rot ◽  
Commonwealth Mycological Institute ◽  
Postharvest Diseases ◽  
First Report ◽  
Postharvest Decay ◽  
Wide Range

A decay of ‘Granny Smith’ apples (Malus domestica Borkh.) was observed in 1988, 1990, and 1991 on fruit grown in the lower Hood River Valley of Oregon and stored at 0°C. Harvested fruit were drenched with thiabendazole and stored in October in all years. In mid-November, fruit were sized, drenched with sodium hypochlorite, and returned to cold storage. Decay was observed in January when fruit were removed from cold storage, sorted, and packed. Decayed areas were light brown and firm with a slightly indefinite margin. Losses were less than 1% of fruit packed. Diseased fruit were surface-disinfested with 95% ethanol, and tissue pieces were transferred aseptically to potato dextrose agar acidified with lactic acid and incubated at approximately 22°C. The fungus consistently isolated was identified as Phytophthora syringae (Kleb.) Kleb. based on morphological characters (3). Sporangia were persistent and averaged 60 μm long (range 59 to 69) × 40 μm wide (range 37 to 43). Antheridia were paragynous, and oospores averaged 37 μm (range 31 to 46). ‘Golden Delicious’, ‘Granny Smith’, and ‘Gala’ apples were inoculated with mycelial plugs from a 7-day-old culture of P. syringae and incubated 12 days at 5°C and 7 to 12 days at 22°C. Twenty fruit of each cultivar were used—ten were inoculated, and ten uninoculated fruit served as controls. Lesions developed on all inoculated fruit but not on uninoculated controls. Lesions were spherical, chocolate brown, and firm with no evidence of external mycelia. Lesion morphology was similar on all cultivars. P. syringae was reisolated from lesion margins of all infected fruit. This postharvest decay of apples has not been observed in the Hood River Valley since 1991. Fruit rot of apples caused by P. syringae is known in Canada (1) and is common in the United Kingdom (2), but has not been reported previously in the United States. To our knowledge, this is the first report of postharvest decay of apples by P. syringae in the United States. References: (1) R. G. Ross and C. O. Gourley. Can. Plant Dis. Surv. 49:33, 1969. (2) A. L. Snowdon. A Color Atlas of Postharvest Diseases. CRC Press, Inc., Boca Raton, FL, 1990. (3) G. M. Waterhouse. The Genus Phytophthora. Misc. Publ. 12. The Commonwealth Mycological Institute, Kew, Surrey, England, 1956.

scholarly journals First Report of Gliocephalotrichum bulbilium Causing Cranberry Fruit Rot in New Jersey and Massachusetts

Plant Disease ◽  
2011 ◽  
Vol 95 (5) ◽  
pp. 618-618 ◽  
Author(s):  
C. Constantelos ◽  
V. P. Doyle ◽  
A. Litt ◽  
P. V. Oudemans
Keyword(s):  
New Jersey ◽  
The United States ◽  
Psidium Guajava ◽  
Fungal Species ◽  
Fruit Rot ◽  
Colletotrichum Acutatum ◽  
Water Control ◽  
First Report ◽  
Brunei Darussalam ◽  
Nephelium Lappaceum

Cranberry (Vaccinium macrocarpon) fruit were collected as part of a fruit rot survey conducted in September 2010 on farms in New Jersey and Massachusetts. There are more than 20 fungal species reported as causing fruit rot (2) and symptoms are generally not diagnostic. The rotted fruit were surface sterilized in a 10% bleach solution for 5 min, sliced in half, and plated on V8 agar (nonclarified). A novel, fast-growing fungus that produced sporulating orange-brown colonies emerged from 5% of the fruit collected on three of the farms included in the survey. The fungus was notable as the only species present in the rotted fruit, suggesting it may be pathogenic. The conidia were produced as gloeoid masses on phialidic conidiogenous cells arranged in a polyverticillate penicillus. The conidiogenous cells were subtended at variable distances by zero to four sterile appendages that formed on the lightly pigmented conidiophore. On the basis of these characteristics, the fungus was identified as a species of Gliocephalotrichum (3). Further investigation of the growth medium revealed the presence of clustered, red-brown chlamydospores that were produced abundantly in all isolates. These structures, also known as bulbils, are restricted to two species in the genus, G. bulbilium and G. longibrachium (1). On average, the bulbils were 42.0 × 48.3 μm and conidia were 5.75 × 2.5 μm. On the basis of size and shape of conidia and presence of bulbils, the isolates were identified as G. bulbilium (1). To confirm the identity of the fungus, genomic DNA was extracted and ITS1-5.8S-ITS2 and the 5′ end of the β-tubulin gene were amplified and sequenced (1). The sequences (GenBank Accession Nos. HQ828060 and HQ828061) were compared with published sequences of Gliocephalotrichum isolates (1) and results confirmed the cranberry isolates were G. bulbilium. The isolates were tested for pathogenicity on harvested cranberry fruit. Fifty ripe cranberry fruit (cv. Stevens) were inoculated by injecting approximately 20 μl (using a 26G 9.5-mm needle) of conidia (1 × 105 ml–1) into the side of each berry. As a comparison, isolates of two common cranberry fruit rot pathogens, Colletotrichum acutatum and C. gloeosporioides, were inoculated on to fruit using the same technique. A water-only inoculation was used as the control. Fruit rot developed on all inoculated fruit except the water control. In the case of G. bulbilium, all fruit rotted within 2 days, whereas the other two species developed symptoms within 4 to 7 days. G. bulbilium and both species of Colletotrichum were consistently reisolated from all of the respectively inoculated fruit. To our knowledge, this is the first report of G. bulbilium causing fruit rot on cranberry. The species has been reported as an important postharvest fruit rot (4) on rambutan (Nephelium lappaceum) in Thailand, rambutan and guava (Psidium guajava) in Hawaii, and durian (Durio spp.) in Brunei Darussalam. This report of G. bulbilium extends the range within the United States to include Louisiana, Hawaii, Wisconsin, West Virginia, New Jersey, and Massachusetts (2). References: (1) C. Decock et al. Mycologia 98:488, 2006. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , 16 December 2010. (3) A. Rossman et al. Mycologia, 85:685, 1993. (4) A. Sivapalan et al. Australas. Plant Pathol. 27:274, 1998.

scholarly journals First Report of Downy Mildew Caused by Peronospora trigonellae on Fenugreek in the United States

Plant Disease ◽  
2009 ◽  
Vol 93 (12) ◽  
pp. 1349-1349 ◽  
Author(s):  
S. Rooney-Latham ◽  
C. L. Blomquist ◽  
J. Turney
Keyword(s):  
United States ◽  
Los Angeles ◽  
Sequence Data ◽  
Leaf Tissue ◽  
The United States ◽  
Grocery Store ◽  
Diagnostic Laboratory ◽  
First Report ◽  
Severe Stunting ◽  
The United Kingdom

Fenugreek (Trigonella foenum-graecum) is a member of the Fabaceae family and is grown worldwide for culinary and medicinal purposes. The leaves are used as an herb while the seeds are used whole, ground as a spice, or germinated and used as sprouts. In November 2008, a fenugreek plant exhibiting leaf spotting and severe stunting was submitted to the CDFA Plant Pest Diagnostics Laboratory from the Los Angeles County Plant Diagnostic Laboratory. The county had received the sample from a homeowner who reported severe dieback of the fenugreek in his backyard planting. The fenugreek is grown by the resident as an annual and is propagated each year from the previous crop's seed. The seed was originally obtained from a local ethnic grocery store in Lakewood, CA. The homeowner stated that he had noticed symptoms for a number of years and that they seemed especially severe during the winter months. The adaxial surfaces of the leaves exhibited small chlorotic spots often at the leaf margins, while the abaxial surfaces exhibited a grayish violet, felty growth. Conidiophores found on the underside of the leaves branched dichotomously 6 to 10 times and were terminally forked. Conidiophores measured 280 to 525 μm (average 420 μm) with slightly swollen bases (7.5 to 10 μm broad). Conidia were slightly pigmented, oblong to ellipsoid, and measured 23 to 33 × 18 to 23 μm (average 27.8 × 20.3 μm). Globose oospores with verruculose walls measured 30 to 40 μm in diameter (average 36.1 μm) and were found embedded in the leaf tissue of older lesions. The pathogen was identified morphologically as Peronospora trigonellae Gaum. (3). Sequences of a portion of the rDNA, including the internal transcribed spacer regions, were obtained using primers DC6 and ITS6 (1). Sequence data for P. trigonellae had not previously been entered into GenBank and no identity was obtained. Pathogenicity experiments attempted by spraying healthy fenugreek seedlings with conidial suspensions were unsuccessful, presumably because of the age of the inoculum. Since fenugreek is not commercially grown in California, the economic importance of this disease is limited. Although P. trigonellae has been reported on fenugreek in Algeria, India, Pakistan, and the United Kingdom (2–4), to our knowledge, this is the first report of its occurrence in California and the United States. A specimen of P. trigonellae has been deposited in the U.S. National Fungus Collection (BPI 879153). References: (1) D. E. L. Cooke et al. Fungal Genet. Biol. 30:17, 2000. (2) D. F. Farr et al. Fungal Databases. Systematic Mycology and Microbiology Laboratory. Online publication. ARS, USDA, 2009, (3) E. A. Gaumann. Beitr. Kryptogamenflora Schweiz 5:216, 1923. (4) D. R. Jones et al. Plant Pathol. 56:891, 2007.

scholarly journals First Report of Colletotrichum scovillei Causing Anthracnose Fruit Rot on Pepper in South Carolina, United States

Plant Disease ◽  
2020 ◽  
Author(s):  
Sean M Toporek ◽  
Anthony P. Keinath
Keyword(s):  
United States ◽  
South Carolina ◽  
Average Length ◽  
The United States ◽  
Fruit Rot ◽  
Lesion Length ◽  
Pathogenicity Test ◽  
Conidial Suspension ◽  
Accession Number ◽  
First Report

Anthracnose fruit rot caused by various Colletotrichum spp. is a serious disease for pepper (Capsicum annuum) growers, resulting in extensive fruit loss (Harp et al. 2008). Samples of five pepper fruits were obtained from two commercial farms in Lexington and Pickens counties, South Carolina, in August and September 2019, respectively. All fruits had two or more soft, sunken lesions covered with salmon-colored spore masses. Pieces of diseased tissue cut from the margins of lesions were surface disinfested in 0.6% sodium hypochlorite, rinsed in sterile deionized water, blotted dry, and placed on one-quarter-strength potato dextrose agar (PDA/4) amended with 100 mg chloramphenicol, 100 mg streptomycin sulfate, and 60.5 mg mefenoxam (0.25 ml Ridomil Gold EC) per liter. Two isolates of Colletotrichum sp. per fruit were preserved on dried filter paper and stored at 10º C. One additional isolate of Colletotrichum sp. had been collected from a jalapeño pepper fruit on a farm in Charleston County, South Carolina, in 1997. Colony morphology of three isolates, one per county, on Spezieller Nährstoffarmer Agar (SNA) was pale grey with a faint orange tint. All isolates readily produced conidia on SNA with an average length of 16.4 μm (std. dev. = 1.8 μm) and a width of 2.2 μm (std. dev. = 0.2 μm). Conidia were hyaline, smooth, straight, aseptate, cylindrical to fusiform with one or both ends slightly acute or round, matching the description of C. scovillei (Damm et al. 2012). The glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and beta-tubulin (TUB2) genes from three isolates were amplified and sequenced with the primer pairs GDF1/GDR1 and T1/Bt2b, respectively. Species within the C. acutatum clade can be readily distinguished with GAPDH or TUB2 (Cannon et al. 2012). The GAPDH and TUB2 sequences for all three isolates were 100% similar to each other and strain CBS 126529 (GAPDH accession number JQ948597; TUB2 accession number JQ949918) of C. scovillei (Damm et al. 2012). GAPDH and TUB2 sequences for each isolate were deposited in GenBank under the accessions MT826948–MT826950 and MT826951-MT826953, respectively. A pathogenicity test was conducted on jalapeño pepper fruits by placing a 10-ul droplet of a 5 x 105 conidial suspension of each isolate onto a wound made with a sterile toothpick. Control peppers were mock inoculated with 10 ul sterile distilled water. A humid chamber was prepared by placing moist paper towels on the bottom of a sealed crisper box. Inoculated peppers were placed on upside-down 60 ml plastic condiment cups. Three replicate boxes each containing all four treatments were prepared. The experiment was repeated once. After 7 days in the humid chamber at 26ºC, disease did not develop on control fruits, whereas soft, sunken lesions covered with salmon-colored spores developed on inoculated fruits. Lesions were measured and C. scovillei was re-isolated onto amended PDA/4 as previously described. Lesion length averaged 15.6 mm (std dev. = 4.1 mm) by 11.5 mm (std dev. = 2.0 mm). Colletotrichum sp. resembling the original isolate were recovered from all inoculated fruit, but not from non-inoculated fruit. C. scovillei has been reported in Brazil in South America and in China, Indonesia, Japan, Malaysia, South Korea, Taiwan, and Thailand in Asia (Farr and Rossman 2020). This is the first report of C. scovillei as the casual organism of anthracnose fruit rot on pepper in South Carolina and the United States.

scholarly journals First Report of Fruit Rot of Ridge Gourd (Luffa acutangula) Caused by Sclerotium rolfsii

2016 ◽  
Vol 17 (1) ◽  
pp. 18-19
Author(s):  
Chandrasekar S. Kousik ◽  
Jennifer Ikerd ◽  
Mihir Mandal
Keyword(s):  
United States ◽  
Sclerotium Rolfsii ◽  
The United States ◽  
Fruit Rot ◽  
Small Scale ◽  
First Report ◽  
Athelia Rolfsii ◽  
History Of ◽  
Sclerotium Rot ◽  
Luffa Acutangula

Ridge gourd is a specialty cucurbit vegetable cultivated in the United States on a small scale for select markets. We report the infection of ridge gourd fruit by Sclerotium rolfsii (teleomorph: Athelia rolfsii). This appears to be the first report of Sclerotium rot of ridge gourd. In fields with history of S. rolfsii, the gourds should be grown on trellis to prevent fruit contact with wet soil. Several fungicides are available to manage S. rolfsii and may have to be applied if and when needed. Accepted for publication 12 January 2016. Published 14 January 2016.

scholarly journals Anthracnose Fruit and Root Necrosis of Strawberry Are Caused by a Dominant Species Within the Colletotrichum acutatum Species Complex in the United States

2019 ◽  
Vol 109 (7) ◽  
pp. 1293-1301 ◽  
Author(s):  
Nan-Yi Wang ◽  
Bruna B. Forcelini ◽  
Natalia A. Peres
Keyword(s):  
United States ◽  
Species Complex ◽  
The United States ◽  
Fruit Rot ◽  
Limiting Factors ◽  
Colletotrichum Acutatum ◽  
Genetic Characteristics ◽  
Significant Difference ◽  
Root Necrosis ◽  
Strawberry Anthracnose

Strawberry anthracnose fruit rot and root necrosis, caused by Colletotrichum acutatum, are primary limiting factors in fruit production fields in the United States. Recent research focusing on the phenotypic and genetic characteristics of this species has shed light on the diversity of the C. acutatum species complex. In this study, we performed multilocus sequence analysis of four genetic loci to characterize 217 C. acutatum isolates collected over a 23-year period from symptomatic plant tissues of strawberry from six different states. The results revealed two Colletotrichum spp. (C. nymphaeae and C. fioriniae), with 97.7% of the isolate collection (212 of 217) belonging to C. nymphaeae as a dominant clonal linage, regardless of the isolation source. No correlation between species groups and geographical origins of the isolates was observed. Further sequence comparison between historical and contemporary isolates showed the same populations being widely distributed throughout the strawberry nurseries and production fields in the United States and Canada. Subsequently, a subset of 12 isolates representing different quinone-outside inhibitor fungicide resistance profiles from root or fruit tissue of strawberry was selected for comparison of pathogenicity on strawberry. In this test, isolates of different resistance groups or different isolation sources exhibited a similar degree of aggressiveness and caused indistinguishable symptoms on strawberry crowns (P = 0.9555 and 0.7873, respectively) and fruit (P = 0.1638 and 0.1141, respectively), although a significant difference among individual isolates was observed in detached-fruit assays (P = 0.0123). Separate pathogenicity tests using isolates of the two species revealed C. nymphaeae being more aggressive than C. fioriniae in infecting strawberry roots and crowns (P = 0.0073). Therefore, given the occurrence and pathogenicity of C. nymphaeae, this species is likely the sole cause responsible for strawberry anthracnose in the United States.

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