First Report of Fusarium acuminatum Causing Postharvest Fruit Rot on Stored Vaccinium corymbosum in China

Ophiopogon japonicus (Linn. f.) is a perennial evergreen in the Liliaceae family that is cultivated in many provinces of China due to its high medicinal and economic value . In April 2019, an unknown root rot disease was observed on the rhizomes of O. japonicus in a commercial production field in Xiangyang City (30.83° N, 112.53° E), Hubei Province. Disease incidence was approximately 10-20%. Symptoms included chlorosis, drooping and rolling of the leaves followed by rapid death of entire plant. Infected roots appeared to be softened, necrotic, and shriveled with reddish fungal growth. Infected tissues were disinfested on surface with 75% ethanol for 30 s and 0.1% HgCl2 for 1 min, rinsed with sterile distilled water, and dried. Small pieces (2 mm × 2 mm) were then excised from disinfested tissue and incubated on potato dextrose agar (PDA) medium at 25 ℃ in the dark. After 3 days of incubation, six isolates with 75% of isolation rate and same colony morphology were sub-cultured and purified by hyphal tip isolation. Purified cultures grew rapidly and media plates (70×70 mm ) were covered with hyphae after 3 to 4 days. Cultures were initially white and became pink or red over 5 days. Microconidia were not observed. Macroconidia were produced from monophialides on branched conidiophores, which were slender, equilaterally curved, and measured 32.5 to 53.5 μm in length and 3.5 to 5.1 μm in width, with three to five septa. All strains were preliminarily identified as Fusarium acuminatum (Eslie and Summerell 2006) on the basis of morphology. To confirm the identity of the pathogen, molecular identification was performed with strain MD1. Following DNA extraction, PCR was performed using the TSINGKE 2×T5 Direct PCR Mix kit. Target areas of amplification were internal transcribed spacer (ITS), RNA polymerase second largest subunit (RPB2) and beta-tubulin gene (TUB2) regions of rDNA, using ITS1,4 (Yin et al. 1990) , RPB2-5f2/7cr (O’Donnell et al. 2010)and Btu-F-F01, Btu-F-R01 primers(Wang et al. 2014), respectively. Nucleotide sequences were deposited in NCBI (GenBank MT525360.1; MW164629; MT588110.1). BLAST analysis of the ITS sequence had 100% similarity to a 517 bp portion of F. acuminatum sequence in GenBank (MK764994.1) ；RPB2 sequence had 100% similarity to a 687 bp portion of F. acuminatum sequence in GenBank (HM068330.1) and TUB2 sequence had 99% similarity to a 964 bp portion of F. acuminatum sequence in GenBank (KT965741.1). A pathogenicity test was performed in laboratory on O. japonicus roots with isolate MD1. Mycelial plugs (5 mm) were excised from the margin of colony cultured for 5 days, and placed on three-years-old tuberous roots covered with wet sterile cotton and kept at 25℃, under 80% relative humidity. Controls were inoculated with non-colonized PDA plugs (5 mm). All treatments had three replicate plants. On incolated plants, white hyphae covered on O. japonicus roots 3 DPI became pink and by 5 DPI, roots had rot symptoms. By comparision, the control plants had no symptoms. The pathogen was reisolated from the inoculated roots and exhibited same morphological characteristics and ITS sequence as those of F. acuminatum. F. acuminatum was reported to cause fruit rot on postharvest pumpkin and Vaccinium corymbosum in China (Li et al. 2019; Wang et al. 2016).To our knowledge, this is the first report of root rot caused by F. acuminatum on O. japonicus in China.

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First Report of Fruit Rot on Postharvest Pumpkin Caused by Fusarium acuminatum in China

Plant Disease ◽

10.1094/pdis-11-18-1957-pdn ◽

2019 ◽

Vol 103 (5) ◽

pp. 1035-1035

Author(s):

Y. G. Li ◽

W. Y. Jiang ◽

D. Jiang ◽

R. T. Wang ◽

S. Tian ◽

...

Keyword(s):

Fruit Rot ◽

First Report ◽

Fusarium Acuminatum

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First Report of Pathogenicity of Fusarium sporotrichioides and Fusarium acuminatum on Sunflowers in the United States

Plant Health Progress ◽

10.1094/php-2010-0915-02-br ◽

2010 ◽

Vol 11 (1) ◽

pp. 42 ◽

Cited By ~ 4

Author(s):

F. Mathew ◽

B. Kirkeide ◽

T. Gulya ◽

S. Markell

Keyword(s):

United States ◽

Helianthus Annuus ◽

The United States ◽

Fusarium Sporotrichioides ◽

Charcoal Rot ◽

Koch’S Postulates ◽

First Report ◽

Fusarium Acuminatum ◽

Helianthus Annuus L ◽

Koch's Postulates

Widespread infection of charcoal rot was observed in a commercial sunflower field in Minnesota in September 2009. Based on morphology, isolates were identified as F. sporotrichioides and F. acuminatum. Koch's postulates demonstrated pathogencity of both species. To our knowledge, this is the first report of F. sporotrichoides and F. acuminatum causing disease on Helianthus annuus L. in the United States. Accepted for publication 23 August 2010. Published 15 September 2010.

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First Report of Neoscytalidium dimidiatum Causing Fruit Rot on Guava (Psidium guajava) in Malaysia

Plant Disease ◽

10.1094/pdis-06-20-1267-pdn ◽

2021 ◽

Vol 105 (1) ◽

pp. 220

Author(s):

S. I. Ismail ◽

K. Ahmad Dahlan ◽

S. Abdullah ◽

D. Zulperi

Keyword(s):

Psidium Guajava ◽

Fruit Rot ◽

First Report ◽

Neoscytalidium Dimidiatum

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First report of Pythium cucurbitacearum causing fruit rot of durian in the Philippines

Journal of Plant Pathology ◽

10.1007/s42161-021-00892-4 ◽

2021 ◽

Author(s):

Tamie C. Solpot ◽

Christian Joseph R. Cumagun

Keyword(s):

The Philippines ◽

Fruit Rot ◽

First Report

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First Report of Pepper Fruit Rot Caused by Fusarium concentricum in China

Plant Disease ◽

10.1094/pdis-03-13-0325-pdn ◽

2013 ◽

Vol 97 (12) ◽

pp. 1657-1657 ◽

Cited By ~ 6

Author(s):

J. H. Wang ◽

Z. H. Feng ◽

Z. Han ◽

S. Q. Song ◽

S. H. Lin ◽

...

Keyword(s):

Fusarium Species ◽

Fruit Rot ◽

Post Inoculation ◽

Distilled Water ◽

Conidial Suspension ◽

Average Growth ◽

First Report ◽

Control Fruit ◽

Pepper Fruit ◽

Fruit Samples

Pepper (Capsicum annuum L.) is an important vegetable crop worldwide. Some Fusarium species can cause pepper fruit rot, leading to significant yield losses of pepper production and, for some Fusarium species, potential risk of mycotoxin contamination. A total of 106 diseased pepper fruit samples were collected from various pepper cultivars from seven provinces (Gansu, Hainan, Heilongjiang, Hunan, Shandong, Shanghai, and Zhejiang) in China during the 2012 growing season, where pepper production occurs on approximately 25,000 ha. Pepper fruit rot symptom incidence ranged from 5 to 20% in individual fields. Symptomatic fruit tissue was surface-sterilized in 0.1% HgCl2 for 1 min, dipped in 70% ethanol for 30 s, then rinsed in sterilized distilled water three times, dried, and plated in 90 mm diameter petri dishes containing potato dextrose agar (PDA). After incubation for 5 days at 28°C in the dark, putative Fusarium colonies were purified by single-sporing. Forty-three Fusarium strains were isolated and identified to species as described previously (1,2). Morphological characteristics of one strain were identical to those of F. concentricum. Aerial mycelium was reddish-white with an average growth rate of 4.2 to 4.3 mm/day at 25°C in the dark on PDA. Pigments in the agar were formed in alternating red and orange concentric rings. Microconidia were 0- to 1-septate, mostly 0-septate, and oval, obovoid to allantoid. Macroconidia were relatively slender with no significant curvature, 3- to 5-septate, with a beaked apical cell and a foot-shaped basal cell. To confirm the species identity, the partial TEF gene sequence (646 bp) was amplified and sequenced (GenBank Accession No. KC816735). A BLASTn search with TEF gene sequences in NCBI and the Fusarium ID databases revealed 99.7 and 100% sequence identity, respectively, to known TEF sequences of F. concentricum. Thus, both morphological and molecular criteria supported identification of the strain as F. concentricum. This strain was deposited as Accession MUCL 54697 (http://bccm.belspo.be/about/mucl.php). Pathogenicity of the strain was confirmed by inoculating 10 wounded, mature pepper fruits that had been harvested 70 days after planting the cultivar Zhongjiao-5 with a conidial suspension (1 × 106 spores/ml), as described previously (3). A control treatment consisted of inoculating 10 pepper fruits of the same cultivar with sterilized distilled water. The fruit were incubated at 25°C in a moist chamber, and the experiment was repeated independently in triplicate. Initially, green to dark brown lesions were observed on the outer surface of inoculated fruit. Typical soft-rot symptoms and lesions were observed on the inner wall when the fruit were cut open 10 days post-inoculation. Some infected seeds in the fruits were grayish-black and covered by mycelium, similar to the original fruit symptoms observed at the sampling sites. The control fruit remained healthy after 10 days of incubation. The same fungus was isolated from the inoculated infected fruit using the method described above, but no fungal growth was observed from the control fruit. To our knowledge, this is the first report of F. concentricum causing a pepper fruit rot. References: (1) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA, 2006. (2) K. O'Donnell et al. Proc. Nat. Acad. Sci. USA 95:2044, 1998. (3) Y. Yang et al. 2011. Int. J. Food Microbiol. 151:150, 2011.

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First Report of Alternaria Leaf Spot Caused by Alternaria sp. on Highbush Blueberry (Vaccinium corymbosum) in South Korea

Plant Disease ◽

10.1094/pdis-04-14-0344-pdn ◽

2014 ◽

Vol 98 (10) ◽

pp. 1434-1434

Author(s):

J.-H. Kwon ◽

D.-W. Kang ◽

M.-G. Cheon ◽

J. Kim

Keyword(s):

South Korea ◽

Leaf Spot ◽

Disease Incidence ◽

Vaccinium Corymbosum ◽

Its Rdna ◽

Universal Primers ◽

Conidial Suspension ◽

First Report ◽

Representative Isolate ◽

Alternaria Sp

In South Korea, the culture, production, and consumption of blueberry (Vaccinium corymbosum) have increased rapidly over the past 10 years. In June and July 2012, blueberry plants with leaf spots (~10% of disease incidence) were sampled from a blueberry orchard in Jinju, South Korea. Leaf symptoms included small (1 to 5 mm in diameter) brown spots that were circular to irregular in shape. The spots expanded and fused into irregularly shaped, large lesions with distinct dark, brownish-red borders. The leaves with severe infection dropped early. A fungus was recovered consistently from sections of surface-disinfested (1% NaOCl) symptomatic leaf tissue after transfer onto water agar and sub-culture on PDA at 25°C. Fungal colonies were dark olive and produced loose, aerial hyphae on the culture surfaces. Conidia, which had 3 to 6 transverse septa, 1 to 2 longitudinal septa, and sometimes also a few oblique septa, were pale brown to golden brown, ellipsoid to ovoid, obclavate to obpyriform, and 16 to 42 × 7 to 16 μm (n = 50). Conidiophores were pale to mid-brown, solitary or fasciculate, and 28 to 116 × 3 to 5 μm (n = 50). The species was placed in the Alternaria alternata group (1). To confirm the identity of the fungus, the complete internal transcribed spacer (ITS) rDNA region of a representative isolate, AAVC-01, was amplified using ITS1 and ITS4 primers (2). The DNA products were cloned into the pGEM-T Easy vector (Promega, Madison, WI) and the resulting pOR13 plasmid was sequenced using universal primers. The resulting 570-bp sequence was deposited in GenBank (Accession No. KJ636460). Comparison of ITS rDNA sequences with other Alternaria spp. using ClustalX showed ≥99% similarity with the sequences of A. alternata causing blight on Jatropha curcas (JQ660842) from Mexico and Cajannus cajan (JQ074093) from India, citrus black rot (AF404664) from South Africa, and other Alternaria species, including A. tenuissima (WAC13639) (3), A. lini (Y17071), and A. longipes (AF267137). Two base substitutions, C to T at positions 345 and 426, were found in the 570-bp amplicon. Phylogenetic analysis revealed that the present Alternaria sp. infecting blueberry grouped separately from A. tenuissima and A. alternata reported from other hosts. A representative isolate of the pathogen was used to inoculate V. corymbosum Northland leaves for pathogenicity testing. A conidial suspension (2 × 104 conidia/ml) from a single spore culture and 0.025% Tween was spot inoculated onto 30 leaves, ranging from recently emerged to oldest, of 2-year-old V. corymbosum Northland plants. Ten leaves were treated with sterilized distilled water and 0.025% Tween as a control. The plants were kept in a moist chamber with >90% relative humidity at 25°C for 48 h and then moved to a greenhouse. After 15 days, leaf spot symptoms similar to those observed in the field developed on the inoculated leaves, whereas the control plants remained asymptomatic. The causal fungus was re-isolated from the lesions of the inoculated plants to fulfill Koch's postulates. To our knowledge, this is the first report of Alternaria sp. on V. corymbosum in South Korea. References: (1) E. G. Simmons. Page 1797 in: Alternaria: An Identification Manual. CBS Fungal Biodiversity Centre, Utrecht, The Netherlands, 2007. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990. (3) M. P. You et al. Plant Dis. 98:423, 2014.

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

Plant Disease ◽

10.1094/pdis-94-5-0634a ◽

2010 ◽

Vol 94 (5) ◽

pp. 634-634 ◽

Cited By ~ 7

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.

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First Report of a Fruit Rot of Pumpkin Caused by Acidivorax avenae subsp. citrulli in Georgia

Plant Disease ◽

10.1094/pdis.1999.83.2.199b ◽

1999 ◽

Vol 83 (2) ◽

pp. 199-199 ◽

Cited By ~ 31

Author(s):

D. B. Langston ◽

R. D. Walcott ◽

R. D. Gitaitis ◽

F. H. Sanders

Keyword(s):

Polyclonal Antibodies ◽

Pcr Amplification ◽

Tween 80 ◽

Soft Rot ◽

Fruit Rot ◽

Identification System ◽

Banding Patterns ◽

First Report ◽

Microbial Identification ◽

Necrotic Spots

In September 1998, a fruit rot was reported affecting pumpkin (Cucurbita pepo) in a commercial field in Terrell Co., Georgia. Symptoms on the surface of fruit occurred as round, necrotic spots or cracks a few millimeters in diameter. With age, the tissue surrounding these lesions became soft and wrinkled. A soft rot expanded into the flesh of the pumpkin, originating from the lesions observed on the surface. In time, infected pumpkins totally collapsed. V-shaped, necrotic lesions occurred at the margin of the leaf and extended inward toward the mid-rib. Samples were collected from the field and bacteria were isolated from fruit and leaf lesions onto King's medium B (1). The bacterium isolated was rod shaped, gram negative, nonflourescent, oxidase positive, Tween 80 positive, carboxymethyl cellulose positive, β-OH butyrate positive, and malonate negative. The bacterium reacted positively with polyclonal antibodies specific for the watermelon fruit blotch pathogen Acidivorax avenae subsp. citrulli and was identified as A. avenae subsp. citrulli by MIDI (Microbial Identification System, Newark, DE) according to statistical analysis of fatty acid data. Results from polymerase chain reaction (PCR) amplification of the bacterium isolated from pumpkin yielded 360-bp fragments that, when digested with the restriction enzyme HaeIII, had DNA banding patterns identical to those of stock A. avenae subsp. citrulli DNA. Koch's postulates were completed successfully with 2-week-old watermelon seedlings. This is the first report of A. avenae subsp. citrulli causing fruit rot of pumpkin in Georgia. Reference: (1) E. O. King et al. J. Lab. Clin. Med. 44:301, 1954.

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