First Report of Thielaviopsis paradoxa Causing Fruit Rot on Sala (Salacca edulis) in Thailand

Sala (Salacca edulis, a hybrid between S. wallichiana and S. glabrescens) is extensively cultivated in Southeast Asia for its highly valued fruit (1). During the rainy season in 1999, a fruit rot of sala caused by Thielaviopsis paradoxa (2) was observed to occur on immature and mature fruits for the first time in Trad and Chantaburi provinces, Thailand. Infected fruit discolored brown to black and appeared rotted with white mycelia on the lesions. Fruit eventually abscised. Conidiophores of the fungus were usually straight and hyaline to pale brown. The conidia (8.75 to 12.5 × 3.75 to 5.5 μm) were cylindrical to elliptical and also hyaline to pale brown. The brown, smooth, and ovate chlamydospores (15 to 25 × 8.7 to 14.5 μm) were borne terminally in chains from short hyphal branches. To fulfill Koch's postulates, six isolates of the fungus were grown on potato-dextrose agar for 7 days. Plugs of mycelia agar (0.5 cm in diameter) from each isolate were inoculated onto fresh fruit (four fruit per isolate) after the surface was disinfected with 10% sodium hypochlorite for 3 min. Non-inoculated fruits with sterile distilled water were served as controls. After incubation at 30°C and 80% RH in a humidity chamber for 4 days, lesions occurred on all the inoculated fruit. The fungus was subsequently recovered from the lesions. One isolate has been deposited in the Fungal Culture Collection, King Mongkut's Institute of Technology, Ladkrabang, Thailand (TF 1-6/1999). References: (1) G. Hamballi et al. 1989. Proceedings of the First PROSEA International Symposia, Indonesia. (2) A. Johnston and C. Booth. 1983. Plant Pathologist's Pocketbook. CMI, Surrey, England.

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First Report of Colletotrichum gloeosporioides on Cyclamen persicum in Florida

Plant Disease ◽

10.1094/pdis.1997.81.2.227c ◽

1997 ◽

Vol 81 (2) ◽

pp. 227-227 ◽

Cited By ~ 1

Author(s):

D. J. Norman

Keyword(s):

Sodium Hypochlorite ◽

Colletotrichum Gloeosporioides ◽

Potato Dextrose Agar ◽

Distilled Water ◽

Severe Damage ◽

Cyclamen Persicum ◽

First Report ◽

Lesion Diameter ◽

Plastic Bags ◽

Stems And Leaves

Between March and April of 1996, an estimated 20% of the Cyclamen persicum Mill. grown in Florida were infected with Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. in Penz. Symptoms included extensive lesions on flowers, stems, and leaves. Acervuli containing masses of spores and dark setae were observed within lesions. The most severe damage was observed on the cultivar Red Delight. Infected tissues were dipped into 0.26% sodium hypochlorite for 5 s, blotted dry, embedded in water agar, and incubated at 27 ± 1°C. Hyphal tips that grew from lesions were transferred to potato dextrose agar (PDA) and incubated under cool-white fluorescent lights. Developing colonies were gray and contained masses of orange conidia. Conidia were straight with rounded or bulbous ends and averaged 16.8 (SD 5.2) × 2.25 (SD 0.54) μm. Three isolates were selected to complete Koch's postulates. Conidia of each isolate were obtained from 3-day-old PDA cultures, and suspended in sterile, distilled water (SDW) to 104 conidia/ml. These suspensions were sprayed till runoff with hand sprayers onto C. persicum plants. Plants were incubated in plastic bags for 24 h at 27°C, then placed in a glasshouse. Within 3 days, lesions had developed on flowers; within 7 days, they were visible on stems and leaves. Lesion diameter varied from 2 to 5 mm; however, lesions soon coalesced, causing leaf, stem, and flower death. The fungus was reisolated from acervuli that developed on the flowers, stems, and leaves, following previously outlined procedures. Inoculation tests were repeated once. Symptoms did not appear on controls sprayed with SDW nor was the teleomorph stage of the pathogen observed.

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First Report of Diplodia seriata Causing Loquat Fruit Rot in Spain

Plant Disease ◽

10.1094/pdis-08-12-0728-pdn ◽

2013 ◽

Vol 97 (3) ◽

pp. 421-421 ◽

Cited By ~ 5

Author(s):

L. Palou ◽

V. Taberner ◽

C. Montesinos-Herrero

Keyword(s):

Fruit Trees ◽

Culture Collection ◽

Potato Dextrose Agar ◽

Fruit Rot ◽

Eriobotrya Japonica ◽

Its2 Region ◽

Malt Extract ◽

Diplodia Seriata ◽

First Report ◽

Branch Dieback

Spain is the second largest loquat (Eriobotrya japonica Lindl.) producer in the world, with about 40,000 t per year. ‘Algerie’ is the main cultivar planted in Alicante province (SE of Spain; Lat. 38.40° N, Long. 0.08° W), where more than 80% of Spanish commercial loquat plantations are located. In a survey of fruit losses at harvest, irregular brownish superficial dry spots (5 to 15 mm) located mainly near the stem end were observed on fruits from different orchards. After incubation at 20°C for 14 days, the spots on fruit expanded rapidly and turned to dark brown or black, producing black, unilocular, ostiolate, and thick-walled pycnidia. Isolation was performed by disinfecting the surface of symptomatic fruits with alcohol and aseptically cutting pieces of infected peel tissue and plating them in potato dextrose agar (PDA) dishes. The potential causal agent (isolate IVIA GCA-5) was identified in the Spanish Type Culture Collection (CECT, University of Valencia, Valencia, Spain). The fungus grew rapidly on both PDA and malt extract agar (MEA) at 26°C, covering the entire plate surface with dark gray mycelium within 4 days. The plate reverse was dark gray to black. The conidia were brown and aseptate, with the apex broadly rounded and the base rounded or truncate, and 23 × 11 μm (n = 50). The identification of Diplodia seriata De Not. was molecularly confirmed with the amplification with the primers ITS1 and ITS4 and subsequent sequencing of the internal transcribed spacer ITS1-5.8S-ITS2 region of the rDNA extracted from the isolate IVIA GCA-5 (GenBank Accession No. JX987099). Furthermore, the region D1/D2 in the 5′ end of the 28S rDNA gene was amplified with the primers NL1 and NL4 and sequenced (JX997743). A nucleotide BLAST analysis showed in both cases 100% identity with D. seriata [EF127892 (3) and AY928050, respectively]. To fulfill Koch's postulates, 5-mm diameter mycelial plugs from 7-day-old colonies of isolate IVIA GCA-5 grown on PDA at 25°C were aseptically transferred to skin wounds on superficially disinfected ‘Algerie’ loquats (one plug per fruit; n = 9). Wounded but not inoculated fruit were used as controls. The experiment was repeated three times. Inoculated fruit developed lesions of 18 to 100 mm after 7 to 21 days of incubation at 20°C. No lesion was observed on controls. The fungus was consistently reisolated from inoculated fruit. D. seriata is a broadly spread pathogen causing cankers, blight, dieback, and fruit rots in vines and many fruit trees. In Spain, it has been reported to cause fruit rot of olive (1) and branch dieback in olive (2) and grapevine (4). To our knowledge, this is the first report worldwide of D. seriata causing loquat fruit rot. References: (1) J. Moral et al. Plant Dis. 92:311, 2008. (2) J. Moral et al. Phytopathology 100:1340, 2010. (3) A. J. L. Phillips et al. Fungal Divers. 25:141, 2007. (4) J. R. Úrbez-Torres et al. Plant Dis. 90:835, 2006.

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Comparison of Acrylamide and Agar Gels by Freeze-Etching

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100080456 ◽

1977 ◽

Vol 35 ◽

pp. 606-607

Author(s):

Russell L. Steere ◽

Eric F. Erbe

Keyword(s):

Electron Microscope ◽

Sodium Hydroxide ◽

Sodium Hypochlorite ◽

Chromic Acid ◽

Distilled Water ◽

Thin Sheets ◽

Acid Cleaning ◽

Agar Gels ◽

Freeze Etching ◽

Water Cut

Thin sheets of acrylamide and agar gels of different concentrations were prepared and washed in distilled water, cut into pieces of appropriate size to fit into complementary freeze-etch specimen holders (1) and rapidly frozen. Freeze-etching was accomplished in a modified Denton DFE-2 freeze-etch unit on a DV-503 vacuum evaporator.* All samples were etched for 10 min. at -98°C then re-cooled to -150°C for deposition of Pt-C shadow- and C replica-films. Acrylamide gels were dissolved in Chlorox (5.251 sodium hypochlorite) containing 101 sodium hydroxide, whereas agar gels dissolved rapidly in the commonly used chromic acid cleaning solutions. Replicas were picked up on grids with thin Foimvar support films and stereo electron micrographs were obtained with a JEM-100 B electron microscope equipped with a 60° goniometer stage.Characteristic differences between gels of different concentrations (Figs. 1 and 2) were sufficiently pronounced to convince us that the structures observed are real and not the result of freezing artifacts.

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Outbreak of Leaf Spot and Fruit Rot in Florida Strawberry Caused by Neopestalotiopsis spp.

Plant Disease ◽

10.1094/pdis-06-20-1290-re ◽

2021 ◽

pp. PDIS-06-20-1290

Author(s):

Juliana S. Baggio ◽

Bruna B. Forcelini ◽

Nan-Yi Wang ◽

Rafaela G. Ruschel ◽

James C. Mertely ◽

...

Keyword(s):

Internal Transcribed Spacer ◽

Phylogenetic Analyses ◽

Morphological Characteristics ◽

Taxonomic Status ◽

Spore Production ◽

Potato Dextrose Agar ◽

Fruit Rot ◽

Low Genetic Diversity ◽

Pathogenicity Tests ◽

A New Species

Pestalotiopsis-like species have been reported affecting strawberry worldwide. Recently, severe and unprecedented outbreaks have been reported in Florida commercial fields where leaf, fruit, petiole, crown, and root symptoms were observed, and yield was severely affected. The taxonomic status of the fungus is confusing because it has gone through multiple reclassifications over the years. Morphological characteristics, phylogenetic analyses, and pathogenicity tests were evaluated for strawberry isolates recovered from diseased plants in Florida. Phylogenetic analyses derived from the combined internal transcribed spacer, β-tub, and tef1 regions demonstrated that although there was low genetic diversity among the strawberry isolates, there was a clear separation of the isolates in two groups. The first group included isolates recovered over a period of several years, which was identified as Neopestalotiopsis rosae. Most isolates recovered during the recent outbreaks were genetically different and may belong to a new species. On potato dextrose agar, both groups produced white, circular, and cottony colonies. From the bottom, colonies were white to pale yellow for Neopestalotiopsis sp. and pale luteous to orange for N. rosae. Spores for both groups were five-celled with three median versicolored cells. Mycelial growth and spore production were higher for the new Neopestalotiopsis sp. isolates. Isolates from both groups were pathogenic to strawberry roots and crowns. However, the new Neopestalotiopsis sp. proved more aggressive in fruit and leaf inoculation tests, confirming observations from the recent outbreaks in commercial strawberry fields in Florida.

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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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Aerosol measurements at the Gual Pahari EUCAARI station: preliminary results from in-situ measurements

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-7241-2010 ◽

2010 ◽

Vol 10 (15) ◽

pp. 7241-7252 ◽

Cited By ~ 41

Author(s):

A.-P. Hyvärinen ◽

H. Lihavainen ◽

M. Komppula ◽

T. S. Panwar ◽

V. P. Sharma ◽

...

Keyword(s):

Rainy Season ◽

In Situ Measurements ◽

Aerosol Size Distribution ◽

Finnish Meteorological Institute ◽

Convective Mixing ◽

Average Fraction ◽

Mode Size ◽

First Time ◽

Pm10 Mass

Abstract. The Finnish Meteorological Institute (FMI), together with The Energy and Resources Institute of India (TERI), contributed to the European Integrated project on Aerosol Cloud Climate and Air Quality Interactions, EUCAARI, by conducting aerosol measurements in Gual Pahari, India, from December 2007 to January 2010. This paper describes the station setup in detail for the first time and provides results from the aerosol in-situ measurements, which include PM and BCe masses, aerosol size distribution from 4 nm to 10 μm, and the scattering and absorption coefficients. The seasonal variation of the aerosol characteristics was very distinct in Gual Pahari. The highest concentrations were observed during the winter and the lowest during the rainy season. The average PM10 concentration (at STP conditions) was 216 μgm−3 and the average PM2.5 concentration was 126 μgm−3. A high percentage (4–9%) of the PM10 mass consisted of BCe which indicates anthropogenic influence. The percentage of BCe was higher during the winter; and according to the diurnal pattern of the BCe fraction, the peak occurred during active traffic hours. Another important source of aerosol particles in the area was new particle formation. The nucleated particles grew rapidly reaching the Aitken and accumulation mode size, thus contributing considerably to the aerosol load. The rainy season decreased the average fraction of particle mass in the PM2.5 size range, i.e. of secondary origin. The other mechanism decreasing the surface concentrations was based on convective mixing and boundary layer evolution. This diluted the aerosol when sun radiation and the temperature was high, i.e. especially during the pre-monsoon day time. The lighter and smaller particles were more effectively diluted.

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Description of the larva of Bromeliagrion rehni (Odonata: Coenagrionidae) with bionomic notes concerning its phytotelmic habitat in central Amazonas, Brazil

Revista Brasileira de Zoologia ◽

10.1590/s0101-81752008000300012 ◽

2008 ◽

Vol 25 (3) ◽

pp. 479-486 ◽

Cited By ~ 2

Author(s):

Sharlene R. da S. Torreias ◽

Ulisses G. Neiss ◽

Neusa Hamada ◽

Ruth L. Ferreira-Keppler ◽

Frederico A.A. Lencioni

Keyword(s):

Rainy Season ◽

Environmental Parameters ◽

Dry Season ◽

Stage Larva ◽

Water Volume ◽

Apical Region ◽

Last Stage ◽

First Time ◽

The Relationship

The last-stage larva of Bromeliagrion rehni Garrison in De Marmels & Garrison, 2005 is described and illustrated and bionomics and habitat information on this species are provided. The study was conducted in the Reserva Florestal Adolpho Ducke, located near Manaus, state of Amazonas, Brazil.Twelve samplings were done between April, 2003 and April, 2005: six in the rainy season and six in the dry season. In each sampling month, 12 bromeliads (Guzmania brasiliensis Ule, 1907, Bromeliaceae) were collected, six of which were terrestrial and six epiphytic, yielding144 samples. A total of 75 specimens of B. rehni were collected. The relationship between larval B. rehni abundance and the measured environmental parameters (volume (ml), pH, season and stratum) was significant (ANCOVA, F = 5.296, d.f. = 130, p < 0.001). Larvae were most abundant in the rainy season (p < 0.01) and water volume was positively related to the abundance of B. rehni. Larvae of B. rehni can be distinguished from those of B. fernandezianum (the only species in the genus with described larvae) by the number of setae in the prementum and by the color of the apical region of the femur. The association of this species with phytotelmata of G. brasiliensis is reported here for the first time.

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First Report of Leaf Spot of Sweet Basil Caused by Cercospora guatemalensis in Korea

Plant Disease ◽

10.1094/pdis-05-12-0436-pdn ◽

2012 ◽

Vol 96 (10) ◽

pp. 1580-1580

Author(s):

J. H. Park ◽

K. S. Han ◽

J. Y. Kim ◽

H. D. Shin

Keyword(s):

Leaf Spot ◽

Morphological Characteristics ◽

Its Region ◽

Culture Collection ◽

Distilled Water ◽

First Report ◽

Sweet Basil ◽

Organic Farm ◽

Leaf Spots ◽

Close Phylogenetic Relationship

Sweet basil, Ocimum basilicum L., is a fragrant herb belonging to the family Lamiaceae. Originated in India 5,000 years ago, sweet basil plays a significant role in diverse cuisines across the world, especially in Asian and Italian cooking. In October 2008, hundreds of plants showing symptoms of leaf spot with nearly 100% incidence were found in polyethylene tunnels at an organic farm in Icheon, Korea. Leaf spots were circular to subcircular, water-soaked, dark brown with grayish center, and reached 10 mm or more in diameter. Diseased leaves defoliated prematurely. The damage purportedly due to this disease has reappeared every year with confirmation of the causal agent made again in 2011. A cercosporoid fungus was consistently associated with disease symptoms. Stromata were brown, consisting of brown cells, and 10 to 40 μm in width. Conidiophores were fasciculate (n = 2 to 10), olivaceous brown, paler upwards, straight to mildly curved, not geniculate in shorter ones or one to two times geniculate in longer ones, 40 to 200 μm long, occasionally reaching up to 350 μm long, 3.5 to 6 μm wide, and two- to six-septate. Conidia were hyaline, acicular to cylindric, straight in shorter ones, flexuous to curved in longer ones, truncate to obconically truncate at the base, three- to 16-septate, and 50 to 300 × 3.5 to 4.5 μm. Morphological characteristics of the fungus were consistent with the previous reports of Cercospora guatemalensis A.S. Mull. & Chupp (1,3). Voucher specimens were housed at Korea University herbarium (KUS). An isolate from KUS-F23757 was deposited in the Korean Agricultural Culture Collection (Accession No. KACC43980). Fungal DNA was extracted with DNeasy Plant Mini DNA Extraction Kits (Qiagen Inc., Valencia, CA). The complete internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 and sequenced. The resulting sequence of 548 bp was deposited in GenBank (Accession No. JQ995781). This showed >99% similarity with sequences of many Cercospora species, indicating their close phylogenetic relationship. Isolate of KACC43980 was used in the pathogenicity tests. Hyphal suspensions were prepared by grinding 3-week-old colonies grown on PDA with distilled water using a mortar and pestle. Five plants were inoculated with hyphal suspensions and five plants were sprayed with sterile distilled water. The plants were covered with plastic bags to maintain a relative humidity of 100% for 24 h and then transferred to a 25 ± 2°C greenhouse with a 12-h photoperiod. Typical symptoms of necrotic spots appeared on the inoculated leaves 6 days after inoculation, and were identical to the ones observed in the field. C. guatemalensis was reisolated from symptomatic leaf tissues, confirming Koch's postulates. No symptoms were observed on control plants. Previously, the disease was reported in Malawi, India, China, and Japan (2,3), but not in Korea. To our knowledge, this is the first report of C. guatemalensis on sweet basil in Korea. Since farming of sweet basil has recently started on a commercial scale in Korea, the disease poses a serious threat to safe production of this herb, especially in organic farming. References: (1) C. Chupp. A Monograph of the Fungus Genus Cercospora. Ithaca, NY, 1953. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology & Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , May 5, 2012. (3) J. Nishikawa et al. J. Gen. Plant Pathol. 68:46, 2002.

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First Report of Diaporthe hongkongensis Causing Fruit rot on Peach (Prunus persica) in China

Plant Disease ◽

10.1094/pdis-07-20-1505-pdn ◽

2021 ◽

Author(s):

Zhou Zhang ◽

Zheng Bing Zhang ◽

Yuan Tai Huang ◽

FeiXiang Wang ◽

Wei Hua Hu ◽

...

Keyword(s):

Prunus Persica ◽

Fruit Rot ◽

Hunan Province ◽

Post Inoculation ◽

Distilled Water ◽

Conidial Suspension ◽

Internal Transcribed Spacer Region ◽

First Report ◽

Representative Isolate ◽

Rot Disease

Peach [Prunus persica (L.) Batsch] is an important deciduous fruit tree in the family Rosaceae and is a widely grown fruit in China (Verde et al., 2013). In July and August 2018, a fruit rot disease was observed in a few peach orchards in Zhuzhou city, the Hunan Province of China. Approximately 30% of the fruit in more than 400 trees was affected. Symptoms displayed were brown necrotic spots that expanded, coalesced, and lead to fruit being rotten. Symptomatic tissues excised from the margins of lesions were surface sterilized in 70% ethanol for 10 s, 0.1% HgCl2 for 2 min, rinsed with sterile distilled water three times, and incubated on potato dextrose agar (PDA) at 26°C in the dark. Fungal colonies with similar morphology developed, and eight fungal colonies were isolated for further identification. Colonies grown on PDA were grayish-white with white aerial mycelium. After an incubation period of approximately 3 weeks, pycnidia developed and produced α-conidia and β-conidia. The α-conidia were one-celled, hyaline, fusiform, and ranged in size from 6.0 to 8.4 × 2.1 to 3.1 μm, whereas the β-conidia were filiform, hamate, and 15.0 to 27.0 × 0.8 to 1.6 μm. For molecular identification, total genomic DNA was extracted from the mycelium of a representative isolate HT-1 and the internal transcribed spacer region (ITS), β-tubulin gene (TUB), translation elongation factor 1-α gene (TEF1), calmodulin (CAL), and histone H3 gene (HIS) were amplified and sequenced (Meng et al. 2018). The ITS, TUB, TEF1, CAL and HIS sequences (GenBank accession nos. MT740484, MT749776, MT749778, MT749777, and MT749779, respectively) were obtained and in analysis by BLAST against sequences in NCBI GenBank, showed 99.37 to 100% identity with D. hongkongensis or D. lithocarpus (the synonym of D. hongkongensis) (Gao et al., 2016) (GenBank accession nos. MG832540.1 for ITS, LT601561.1 for TUB, KJ490551.1 for HIS, KY433566.1 for TEF1, and MK442962.1 for CAL). Pathogenicity tests were performed on peach fruits by inoculation of mycelial plugs and conidial suspensions. In one set, 0.5 mm diameter mycelial discs, which were obtained from an actively growing representative isolate of the fungus on PDA, were placed individually on the surface of each fruit. Sterile agar plugs were used as controls. In another set, each of the fruits was inoculated by application of 1 ml conidial suspension (105 conidia/ml) by a spray bottle. Control assays were carried out with sterile distilled water. All treatments were maintained in humid chambers at 26°C with a 12-h photoperiod. The inoculation tests were conducted twice, with each one having three fruits as replications. Six days post-inoculation, symptoms of fruit rot were observed on inoculated fruits, whereas no symptoms developed on fruits treated with agar plugs and sterile water. The fungus was re-isolated and identified to be D. hongkongensis by morphological and molecular methods, thus fulfilling Koch’s Postulates. This fungus has been reported to cause fruit rot on kiwifruit (Li et al. 2016) and is also known to cause peach tree dieback in China (Dissanayake et al. 2017). However, to our knowledge, this is the first report of D. hongkongensis causing peach fruit rot disease in China. The identification of the pathogen will provide important information for growers to manage this disease.

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First Report of Butternut Canker Caused by Sirococcus clavigignenti-juglandacearum in New Brunswick, Canada

Plant Disease ◽

10.1094/pdis.1998.82.11.1282b ◽

1998 ◽

Vol 82 (11) ◽

pp. 1282-1282 ◽

Cited By ~ 16

Author(s):

K. J. Harrison ◽

J. E. Hurley ◽

M. E. Ostry

Keyword(s):

New Brunswick ◽

Prince Edward Island ◽

Stem Canker ◽

Culture Collection ◽

Maritime Provinces ◽

Natural Range ◽

Young Branch ◽

First Time ◽

Branch Canker ◽

Butternut Canker

In June 1997, butternut canker was found for the first time in New Brunswick, Canada, at Stickney, Carleton County. A fungal isolate recovered from a young branch canker on butternut (Juglans cinerea L.), cultured on potato dextrose agar, produced spores and cultural morphology as previously described (1). This strain was retained as FSC-758 in the Fredericton Stock Culture Collection at the Atlantic Forestry Centre. The disease was also detected at four other locations in Carleton County along the Saint John River watershed within 20 km of the State of Maine. One stem canker examined at Peel, Carleton County, suggests the disease has been present at this site in New Brunswick for at least 7 years. The butternut tree is at the northeastern edge of its natural range in New Brunswick and, prior to the pathogen's detection, was believed to be far enough from infected butternut in the northeastern United States, Ontario, and Quebec to escape infection. Because planted specimens of butternut exist outside the tree's natural range in New Brunswick and in the neighboring provinces of Nova Scotia and Prince Edward Island, efforts are underway to determine how far the fungus has spread in the Maritime Provinces. Reference: (1) V. M. G. Nair et al. Mycologia 71:641, 1979.

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