First Report of Mango Anthracnose Caused by Colletotrichum karstii in Brazil

From April to June 2010, mango fruits (Mangifera indica L.) (cv. Tommy Atkins) showing post-harvest anthracnose symptoms were collected during a survey conducted in São Francisco Valley, northeastern Brazil. Fruits affected by anthracnose showed sunken, prominent, dark brown to black decay spots. Small pieces (4 to 5 mm) of necrotic tissues were surface sterilized for 1 min in 1.5% NaOCl, washed twice with sterile distilled water, and plated onto potato dextrose agar (PDA) amended with 0.5 g liter–1 streptomycin sulfate. Plates were incubated at 25°C in the dark for 5 to 7 days and colonies that were morphologically similar to species of Colletotrichum were transferred to PDA (1). Identification was made using morphological characteristics and phylogenetic analysis. Two isolates (CMM 4101 and CMM 4102) presented colonies that had white aerial mycelia and orange conidial mass, varying between colorless and pale orange in reverse. Conidia were hyaline, cylindrical, and aseptate 14.52 (10.40 to 20.20) μm long and 4.90 (3.80 to 6.50) μm wide, length/width ratio = 3.0. Mycelial growth rate was 5.20 mm per day at 25°C. Morphological and cultural characterizations were consistent with the description of Colletotrichum karstii (3). PCR amplification by universal primers (ITS1/ITS4) and DNA sequencing of the internal transcribed spacer (ITS1-5.8S-ITS2 rRNA gene cluster) were conducted to confirm the identifications. Analysis of representative sequences (GenBank Accession Nos. HM585409 and HM585406) suggested that the isolated pathogen was C. karstii. Using published ITS data for C. karstii (3), a phylogenetic analysis was made via Bayesian inference, which shows that the isolated fungi belong to the C. karstii clade. Sequences of the isolates obtained in this study were deposited in GenBank (KC295235 and KC295236), and cultures were deposited in the Culture Collection of Phytopathogenic Fungi of the Universidade Federal Rural de Pernambuco (CMM, Recife, Brazil). Pathogenicity tests were conducted with the C. karstii strains on mango fruits cv. Tommy Atkins. Mycelial plugs taken from the margin of actively growing colonies (PDA) of each isolate were applied in shallow wounds (0.4 cm in diameter) at the medium region of the each fruit. PDA discs without fungal growing were used as controls. Inoculated fruits were placed in plastic containers lined with paper towels wetted in distilled water. The containers were partially sealed with plastic bags to maintain high humidity and incubated at 25°C in the dark. The plastic bags and paper towels were removed after 24 h, and fruits were kept at the same temperature. The experiment was arranged in a completely randomized design with four replicates per treatment (isolate) and four fruits per replicate. Typical anthracnose symptoms were observed after 10 days in mango fruits. C. karstii was successfully reisolated from symptomatic mango fruits to fulfill Koch's postulates. C. karstii was previously described from Orchidaceae in southwest China and the United States (2,3). To our knowledge, this is the first report of C. karstii causing mango anthracnose in Brazil and worldwide. References: (1) U. Damm et al. Stud. Mycol. 73:1, 2012. (2) I. Jadrane et al. Plant Dis. 96:1227, 2012. (3) Yang et al. Cryptogamie Mycol. 32:229, 2011.

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First Report of Mango Dieback Caused by Pseudofusicoccum stromaticum in Brazil

Plant Disease ◽

10.1094/pdis-05-11-0425 ◽

2012 ◽

Vol 96 (1) ◽

pp. 144-144 ◽

Cited By ~ 8

Author(s):

M. W. Marques ◽

N. B. Lima ◽

S. J. Michereff ◽

M. P. S. Câmara ◽

C. R. B. Souza

Keyword(s):

Uv Light ◽

Mangifera Indica ◽

Morphological Characteristics ◽

Pcr Amplification ◽

Molecular Techniques ◽

Northeastern Brazil ◽

Universal Primers ◽

Rrna Gene ◽

First Report ◽

Length Width

From September to December 2010, mango (Mangifera indica L.) stems showing dieback symptoms were collected during a survey conducted in São Francisco Valley, northeastern Brazil. Small pieces (4 to 5 mm) of necrotic tissues were surface sterilized for 1 min in 1.5% NaOCl, washed twice with sterile distilled water, and plated onto potato dextrose agar (PDA) amended with 0.5 g liter–1 streptomycin sulfate. Plates were incubated at 25°C in the dark for 14 to 21 days and colonies that were morphologically similar to species of Botryosphaeriaceae were transferred to PDA. Colonies developed a compact mycelium that was initially white, but becoming gray dark after 4 to 6 days of incubation at 25°C in darkness. Identification was made using morphological characteristics and DNA based molecular techniques. Pycnidia were obtained on 2% water agar with sterilized pine needles as substratum after 3 weeks of incubation at 25°C under near-UV light. Pycnidia were large, multilocular, eustromatic, covered with hyphae; locule totally embedded without ostioles, locule walls consisting of a dark brown textura angularis, becoming thinner and hyaline toward the conidiogenous region. Conidia were hyaline, thin to slightly thickened walled, aseptate, with granular contents, bacilliform, straight to slightly curved, apex and base both bluntly rounded or just blunt, 15.6 to 25.0 (20.8) μm long, and 2.7 to 7.9 (5.2) μm wide, length/width = 4.00. According to these morphological characteristics, three isolates (CMM1364, CMM1365, and CMM1450) were identified as Pseudofusicoccum stromaticum (1,3,4). PCR amplification by universal primers (ITS4/ITS5) and DNA sequencing of the internal transcribed spacer (ITS1-5.8S-ITS2 rRNA gene cluster) were conducted to confirm the identifications through BLAST searches in GenBank. The isolates were 100% homologous with P. stromaticum (3) (GenBank Accession Nos. AY693974 and DQ436935). Representative sequences of the isolates were deposited in GenBank (Accession Nos. JF896432, JF966392, and JF966393). Pathogenicity tests were conducted with the P. stromaticum strains on 5-month-old mango seedlings (cv. Tommy Atkins). Mycelial plugs taken from the margin of actively growing colonies (PDA) of each isolate were applied in shallow wounds (0.4 cm in diameter) on the stem (center) of each plant. Inoculation wounds were wrapped with Parafilm. Control seedlings received sterile PDA plugs. Inoculated and control seedlings (five each) were kept in a greenhouse at 25 to 30°C. After 5 weeks, all inoculated seedlings showed leaf wilting, drying out of the branches, and necrotic lesions in the stems. No symptoms were observed in the control plants. P. stromaticum was successfully reisolated from symptomatic plants to fulfill Koch's postulates. P. stromaticum was described from Acacia, Eucalyptus, and Pinus trees in Venezuela (3,4), and there are no reports of this fungus in other hosts (2). To our knowledge, this is the first report of P. stromaticum causing mango dieback in Brazil and worldwide. References: (1) P. W. Crous et al. Stud. Mycol. 55:235, 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/ , 18 May 2011. (3) S. Mohali et al. Mycol. Res. 110:405, 2006. (4) S. R. Mohali et al. Fungal Divers. 25:103, 2007.

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First Report of Black Rot of Carrots Caused by Alternaria radicina in Michigan

Plant Disease ◽

10.1094/pd-90-0684b ◽

2006 ◽

Vol 90 (5) ◽

pp. 684-684

Author(s):

C. Saude ◽

M. K. Hausbeck

Keyword(s):

United States ◽

New York ◽

Sequence Similarity ◽

Morphological Characteristics ◽

Its Region ◽

The United States ◽

Distilled Water ◽

First Report ◽

Plastic Bags ◽

Alternaria Sp

In April 2005, an Alternaria sp. was isolated from carrot (Daucus carota) roots harvested in the fall of 2004 and held at 1 to 3°C in a storage facility in Newaygo County, MI. The pathogen was readily isolated on water agar from root tissue exhibiting grayish black, sunken lesions. Morphological characteristics were noted 5 to 7 days after single-conidium cultures were established on potato dextrose agar (3). Sixteen Alternaria sp. isolates were recovered. Cultures were dark olive brown, and conidia were pigmented, ellipsoidal, and produced singly or in chains of two. Conidia were 35 to 45 μm long and 15 to18 μm in diameter, usually with three to eight transverse and one to four longitudinal septa. Pathogenicity of isolates was tested on carrot roots in the laboratory and carrot seedlings (cv. Goliath) in the greenhouse. In the laboratory, four surface-sterilized, whole carrot roots were sprayed until runoff with 2 × 106 conidia/ml of each isolate and incubated at 23 to 25°C in a moist chamber for 10 days. Controls were sprayed with sterile distilled water. Ten to fifteen days after inoculation, inoculated carrots exhibited grayish black, sunken lesions, and an Alternaria sp. was reisolated from the margin of the lesions. Controls remained healthy. In the greenhouse, seven pots containing one 2-week-old carrot seedling were watered to saturation and plants were sprayed until runoff with 2 × 106 conidia/ml for each isolate. Control plants were sprayed with sterile distilled water. After inoculation, plants were enclosed in clear plastic bags, placed under 63% woven shade cloth and watered regularly. Black lesions were observed on the foliage 7 days after inoculation, and wilt and death of plants were observed 15 to 30 days after inoculation. Alternaria sp. was reisolated from the foliage of symptomatic plants. Control plants remained healthy. DNA was extracted from all isolates, and the nuclear ribosomal internal transcribed spacer (ITS) region amplified with primers ITS4 and ITS5 and sequenced. A portion of the ITS sequence has been deposited in the NCBI database (GenBank Accession No. DQ394073). A BLAST search of the NCBI database with the ITS sequences revealed A. radicina, Accession No AY154704, as the closest match with 100% sequence similarity. In September 2005, an Alternaria sp. was isolated from black lesions on carrot roots, crowns, and foliage that were collected from fields in Newaygo and Oceana counties, MI. The recovered isolates were morphologically similar to A. radicina isolates obtained from stored carrots in April 2005. First isolated and identified on stored carrots in New York (3), A. radicina is also present in other carrot-producing areas of the United States (1) and was isolated not only from stored carrots but also from carrots in the field (2) and carrot seeds (4). To our knowledge, this is the first report of A. radicina on stored and field carrots in Michigan, which signifies a serious risk to a carrot industry that ranks among the top five in the United States. References: (1) D. F. Farr et al. Fungi on Plants and Plant Produce in the United States.The American Phytopathological Society, St. Paul, MN, 1989. (2) R. G. Grogan and W. C. Snyder. Phytopathology 42:215, 1952. (3) F. C. Meier and E. D. Eddy. Phytopathology 12:157, 1922. (4) B. M. Pryor and R. L. Gilbertson. Plant Dis. 85:18, 2001.

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First Report of Volutella Blight on Pachysandra Caused by Volutella pachysandricola in China

Plant Disease ◽

10.1094/pdis-11-11-0997 ◽

2012 ◽

Vol 96 (4) ◽

pp. 584-584

Author(s):

Q. Bai ◽

Y. Xie ◽

R. Dong ◽

J. Gao ◽

Y. Li

Keyword(s):

Morphological Characteristics ◽

Stem Canker ◽

Botanical Garden ◽

The United States ◽

Culture Collection ◽

Leaf Blight ◽

Conidial Suspension ◽

First Report ◽

Leaf Spots ◽

Plastic Bags

Pachysandra (Pachysandra terminalis, Buxaceae) and Japanese Pachysandra, also called Japanese Spurge, is a woody ornamental groundcover plant distributed mostly in Zhejiang, Guizhou, Henan, Hubei, Sichuan, Shanxi, and Gansu provinces in China. In April 2010, P. terminalis asymptomatic plants were shipped from Beijing Botanical Garden Institute of Botany Chinese Academy of Science to the garden nursery of Jilin Agricultural University (43°48′N, 125°23′E), Jilin Province. In June 2011, Volutella blight (sometimes called leaf blight and stem canker) of P. terminalis was observed on these plants. Infected leaves showed circular or irregular, tan-to-brown spots often with concentric rings and dark margins. The spots eventually grew and coalesced until the entire leaf died. Cankers appeared as greenish brown and water-soaked diseased areas, subsequently turning brown or black, and shriveled and often girdled the stems and stolons. During wet, humid weather in autumn, reddish orange, cushion-like fruiting structures of the fungus appeared on the stem cankers and undersides of leaf spots. Symptoms of the disease were consistent with previous descriptions (2–4). Five isolates were obtained from necrotic tissue of leaf spots and cankers of stems and stolons and cultured on potato dextrose agar. The colony surface was salmon colored and slimy. Conidia were hyaline, one celled, spindle shaped, and 12.57 to 22.23 × 3.33 to 4.15 μm with rounded ends. Morphological characteristics of the fungus were consistent with the description by Dodge (2), and the fungus was identified as Volutella pachysandricola (telemorph Pseudonectria pachysandricola). The internal transcribed spacer (ITS) regions of the nuclear rDNA were amplified using primers ITS4/ITS5 (1). The ITS sequences were 553 bp long and identical among these five isolates (GenBank Accession No. HE612114). They were 100% identical to Pseudonectria pachysandricola voucher KUS-F25663 (Accession No. JN797821) and 99% identical to P. pachysandricola culture-collection DAOM (Accession No. HQ897807). Pathogenicity was confirmed by spraying leaves of clonally propagated cuttings of P. terminalis with a conidial suspension (1 × 106 conidia/ml) of the isolated V. pachysandricola. Control leaves were sprayed with sterile water. Plants were covered with plastic bags and kept in a greenhouse at 20 to 25°C for 72 h. After 5 to 8 days, typical disease symptoms appeared on leaves, while the control plants remained healthy. V. pachysandricola was reisolated from the leaf spots of inoculated plants. Pachysandra leaf blight and stem canker also called Volutella blight, is the most destructive disease of P. terminalis and previously reported in the northern humid areas of the United States (Illinois, Connecticut, Ohio, Indiana, Iowa, Massachusetts, Missouri, Kentucky, and Wisconsin), northern Europe (Britain, Germany, and Poland), and the Czech Republic. To our knowledge, this is the first report of the disease caused by V. pachysandricola in China. The disease may become a more significant problem in P. terminalis cultivation areas if the disease spreads on P. terminalis in nursery beds. References: (1) D. E. L. Cooke et al. Mycol. Res. 101:667, 1997. (2) B. O. Dodge. Mycologia 36:532, 1944. (3) S. M. Douglas. Online publication. Volutella Blight of Pachysandra. The Connecticut Agricultural Experiment Station, 2008. (4) I. Safrankova. Plant Protect. Sci.43:10, 2007.

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First Report of Impatiens Downy Mildew Caused by Plasmopara obducens in Kentucky

Plant Disease ◽

10.1094/pdis-10-12-0973-pdn ◽

2013 ◽

Vol 97 (3) ◽

pp. 428-428 ◽

Cited By ~ 3

Author(s):

N. A. Ward ◽

E. Dixon ◽

B. Amsden

Keyword(s):

Downy Mildew ◽

Ribosomal Subunit ◽

Fungal Growth ◽

The United States ◽

Diseased Plant ◽

Distilled Water ◽

First Report ◽

Plastic Bags ◽

Impatiens Walleriana ◽

Black Plastic

Impatiens downy mildew (Plasmopara obducens (J. Schröt.) J. Schröt. (syn Peronospora obducens) was first reported in the United States in 2004, but widespread outbreaks were observed throughout North America in 2011 (5). In June 2012, symptoms, including severe defoliation while plants retained upright stems, were observed on approximately 100 landscape impatiens (Impatiens walleriana Hook.f.) in Franklin County in central Kentucky. All plants in the landscape were affected. Plants were primarily defoliated and remaining leaves were stunted, mottled, and chlorotic with edges curled downward; no flowers were present. Under examination with a dissecting microscope, white downy fungal growth was observed. Closer examination confirmed that the growth consisted of colorless sporangiophores that were mainly unbranched, straight, and rigid (1,3). Sporangiophores consisted of apical branches attached at right angles to main axes, ranging from 67.2 to 89.9 μm long (1). Sporangia were ovoid and hyaline, measuring 11.2 to 13.3 μm × 8.2 to 10.7 μm (3). No oospores were observed. Pathogenicity tests were performed by inoculating 20 to 40 leaves on three plants each of the cvs. Dazzler and Super Elfin with suspensions of 1 × 105 sporangiophores per ml in sterile distilled water. Sporangia were obtained by washing infected leaves with sterile distilled water, and inoculations were completed by spraying leaves until runoff. Plants sprayed with sterile water served as controls. Plants were covered with black plastic bags for 48 h and then maintained under fluorescent lights for 10 days at room temperature (22 to 25°C). Sporangiophores were recovered from inoculated plants after 10 days, and morphology matched original inoculum; symptoms included chlorotic, downward curling leaves with sporulation on the undersides. Non-inoculated plants did not develop symptoms after 21 days. Molecular identification of the pathogen was conducted using three leaves from one plant from each cultivar. PCR was conducted by amplifying the large ribosomal subunit DNA using primers NL-1 and NL-4 (2). Amplicons of 762 to 691 bp were produced from diseased plant tissue that contained visible sporangiophores, and the bands were extracted from the gel and purified. Sequence results confirmed 100% similarity to accessions from Florida (GenBank Accession No. JX217746.1) and Ohio (JX142134.1) and 99% similarity to amplicons reported from Serbia (HQ246451.1) and UK (AY587558.1). This is believed to be the first report of downy mildew infecting impatiens in Kentucky. References: (1) O. Constantinescu. Mycologia 83:473, 1991. (2) W. Maier et al. Can. J. Bot 81:12, 2003. (3) P. A. Saccardo. Syllogue Fungorum 7:242, 1888. (4) S. N. Wegulo et al. Plant Dis. 88:909, 2004.

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First Report of Stem-End Rot of Mango Caused by Phomopsis mangiferae in Taiwan

Plant Disease ◽

10.1094/pdis-93-7-0764a ◽

2009 ◽

Vol 93 (7) ◽

pp. 764-764 ◽

Cited By ~ 2

Author(s):

Y. Ko ◽

C. W. Liu ◽

C. Y. Chen ◽

S. Maruthasalam ◽

C. H. Lin

Keyword(s):

Mangifera Indica ◽

Morphological Characteristics ◽

Pathogenic Fungi ◽

The United States ◽

Fluorescent Light ◽

Continuous Exposure ◽

Tropical Fruit ◽

First Report ◽

Agar Plug ◽

Rot Disease

Mango (Mangifera indica L.) is grown on approximately 20,000 ha in Taiwan. It is an economically important crop and the income of many fruit farmers comes primarily from mango production. During 2006 and 2007, a stem-end rot disease was observed 1 week after harvest on 28 to 36% of stored mangoes picked from six orchards in the Pingtung, Tainan, and Kaoshiung regions. Two popular mango cultivars, Keitt and Irwin, showed greater susceptibility to this disease, while ‘Haden’ was found to be moderately susceptible. In storage, symptoms initially appeared as light-to-dark brown lesions surrounding peduncles. Rot symptoms advanced slowly but eventually penetrated the mesocarp, which consequently reduced the commercial value of fruits. The fungus formed abundant pycnidia (0.1 to 0.6 mm in diameter) on infected fruits in advanced stages of symptom development. Pieces of symptomatic fruits plated on acidified potato dextrose agar (PDA) and incubated at 25 ± 1°C consistently yielded the same fungus. A single conidial isolate was cultured. Pycnidia developed on PDA after continuous exposure to light for 9 to 14 days. On the basis of morphological characteristics, the fungus was identified as Phomopsis mangiferae L. (2,3). Pycnidia released two types of conidia: α-conidia (5 to 10 × 2.3 to 4.0 μm) were hyaline and oval to fusoid; and β-conidia (15.0 to 37.5 × 1.3 to 2.5 μm) were hyaline and filiform with characteristic curves. Conidiophores were hyaline, filiform, simple or branched, septate, and 15 to 75 μm long. Cultures incubated under continuous fluorescent light (185 ± 35 μE·m–2·s–1) at 25°C for 3 days were used as inoculum for pathogenicity tests. Five fruits from ‘Keitt’ were wounded with a sterilized scalpel and each wound (2 × 2 × 2 mm) was inoculated with either a 5-mm mycelium agar plug or a 0.5-ml spore suspension (105 conidia per ml) of the fungus. Five wounded fruits inoculated with 5-mm PDA plugs or sterile water alone served as controls. Inoculated areas were covered with moist, sterile cotton. Fruits were enclosed in plastic bags and incubated at 24°C for 3 days. The test was performed three times. The same symptoms were observed on all inoculated fruits, whereas no decay was observed on control fruits. Reisolations from the inoculated fruits consistently yielded P. mangiferae, thus fulfilling Koch's postulates. This disease has previously been reported in Australia, Brazil, China, Cuba, India, Malaysia, and the United States (1). To our knowledge, this is the first report of P. mangiferae causing stem-end rot disease on mangoes in Taiwan. Our report necessitates taking preventive strategies in the field, prior to or after harvest, to contain postharvest losses in mangoes. References: (1) G. I. Johnson. Page 39 in: Compendium of Tropical Fruit Diseases. R. C. Ploetz et al., eds. The American Phytopathological Society. St. Paul, MN, 1994. (2) R. C. Ploetz, ed. Page 354 in: Diseases of Tropical Fruit Crops. CABI Publishing. Wallingford, UK, 2003. (3) E. Punithalingam. No. 1168 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1993.

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First report of Colletotrichum tropicale causing anthracnose on Passiflora edulis in Brazil

Plant Disease ◽

10.1094/pdis-07-20-1440-pdn ◽

2021 ◽

Author(s):

Jackeline Laurentino da Silva ◽

Walisson Ferreira da Silva da Silva ◽

Luiz Eduardo Monteiro Lopes ◽

Maria Jussara dos Santos Silva ◽

Janaíne Rossane Araújo Silva-Cabral ◽

...

Keyword(s):

Filter Paper ◽

Morphological Characteristics ◽

Oxygen Demand ◽

Negative Control ◽

Passion Fruit ◽

Northeastern Brazil ◽

Distilled Water ◽

Passiflora Edulis ◽

First Report ◽

Colletotrichum Tropicale

Brazil is the world's largest producer and consumer of yellow passion fruit (Passiflora edulis f. flavicarpa), mainly for the manufacture of concentrate and frozen juice as well as for fresh consumption (Faleiro et al. 2005). Between June and July 2018, passion fruit plants with symptoms of anthracnose were observed in commercial planting in the municipality of Coruripe (20 ha), northeastern state of Alagoas, Brazil. Approximately 70% of the plants showed leaves with relatively large, watery, circular spots that affected 30% of the leaf surface. Small fragments taken from the transition region of symptomatic tissue were superficially disinfected in 70% ethanol for 30 s and in 1% NaClO for 1 min, rinsed in sterile distilled water (SDW), dried on filter paper, plated on potato dextrose agar (PDA-Kasvi) incubated at 25°C under white light and 12 h photoperiod, for 3 days. Two isolates were obtained and deposited in the Collection of Phytopathogens at the Universidade Federal de Alagoas (COUFAL0281 and COUFAL0282). To identify the isolates, partial sequences of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and β-tubulin (TUB2) genes and of the rDNA-ITS (ITS) region were amplified by PCR. The partial sequences were deposited at GenBank (MT299339, MT334694, MT310553, MT299340, MT334695 and MT310554). Based on the BLASTn analysis, sequences of the PCR products showed high nucleotide similarity with sequences of the species C. tropicale (CBS 124949/ex-type and ICMP 18672), for GAPDH (98.94% and 100%), TUB2 (99 and 100%) genes and ITS (100%). This result was also confirmed in the phylogenetic tree of Bayesian Inference assembled with concatenated data (GAPDH, TUB2 and ITS). The colonies of the isolates were white with a white reverse, with dense mycelium, and mean growth rate of 7.54 mm/day, after 7 days on PDA medium at 25° C. Conidia were subcylindrical with rounded ends, hyaline, smooth walls and measured 13.63-20.59μm (= 17.54μm; n= 50) in length and 4.40-7.93 μm (= 5.88 μm; n= 50) in width. Appressoria were melanized, subglobose, irregular and measured 7.44 - 18.57 μm (= 10.04 μm; n= 50) in length and 5.49-10.16 μm (= 7.66 μm; n= 50) in width. These morphological characteristics were consistent with those described for Colletotrichum tropicale E.I. Rojas, S.A. Rehner & Samuels (Rojas et al. 2010). To confirm pathogenicity, 30 µL of a 106 conidia/mL sterile distilled water (SDW) conidia suspension, together with a drop of 20% Tween were deposited on the adaxial surface of passion fruit leaves wounded with a sterile needle, with four repetitions. The control consisted of leaves inoculated only with SDW. The leaves were placed in a plastic Gerbox box with sterilized filter paper moistened with SDW and maintained in a Biochemistry Oxygen Demand (BOD) incubator stove at 25 ºC and photoperiod of 12 h. After 7 days, typical anthracnose symptoms were observed on inoculated leaves. The pathogen was re-isolated and confirmed by morphological characterization, according to Koch's postulates. No symptoms were observed in the negative control. The occurrence of this species has been frequently reported in several other crops grown in northeastern Brazil (Silva et al. 2017; Veloso et al. 2018; Vieira et al. 2018; Costa et al. 2019). Additionally, many of these crops are grown in close proximity to the passion fruit orchards, thus favoring pathogen movement between hosts, probably, due to the anthropic influence, circulation of animals and insects, as well as wind driven rain splashes. However, this is first report of C. tropicale in Passiflora edulis in the world.

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First Report of Daylily Leaf Streak Caused by Kabatiella microsticta in China

Plant Disease ◽

10.1094/pdis-04-12-0381-pdn ◽

2012 ◽

Vol 96 (10) ◽

pp. 1579-1579 ◽

Cited By ~ 1

Author(s):

Q. R. Bai ◽

S. Han ◽

Y. Y. Xie ◽

R. Dong ◽

J. Gao ◽

...

Keyword(s):

Morphological Characteristics ◽

Its Region ◽

The United States ◽

Control Treatment ◽

Conidial Suspension ◽

First Report ◽

Perennial Plant ◽

Leaf Spots ◽

Plastic Bags ◽

Hemerocallis Citrina

Daylily (Hemerocallis spp.) is an herbaceous, perennial plant, cultivated for its flowers. Daylily is sold in Asian markets as fresh or dried flowers (the flowers of some species, e.g., Hemerocallis citrina, are edible) or as the corm, which is used for medicinal purposes. In June 2011, daylily leaf streak was found in a nursery of Jilin Agricultural University, Jilin Province, China. Symptoms included water-soaked, irregular spots along the leaf midvein that turned orange to reddish brown and eventually enlarged to coalesce into extensive, necrotic streaks along the length of the leaf, as previously reported (2). Heavily infected leaves often withered and died. Four isolates were recovered from necrotic tissue of leaf spots and cultured on potato dextrose agar (PDA) at 25°C. All colonies were initially cream to peach colored and appeared slimy. With the maturation of the culture, the colonies became dark brown to black with sparse aerial hyphae. Blastic conidia formed simultaneously on intercalary or terminal, undifferentiated conidiogenous cells, and were scattered in dense sections on culture surface. When the conidia dropped from conidiogenous cell, an indistinct scar or a denticle remained. Conidia were hyaline, one-celled, smooth, ellipsoidal, and variable in size (2.73 to 6.01 × 8.45 to 19.36 μm), and all morphological characteristics were consistent with Kabatiella microsticta Bubak (syn. Aureobasidium microstictum; 2,4). The internal transcribed spacer (ITS) region of the nuclear rDNA was amplified using primers ITS4/ITS5 (1). ITS (534 bp) was identical among all four isolates (GenBank Accession No. HE798117) and 100% identical to that of K. microsticta CBS 114.64 (FJ150873). Pathogenicity was confirmed by spraying 20 seedlings of daylily, propagated in tissue-culture medium, with a conidial suspension (106 conidia/ml) of each isolate. A second set of 20 seedlings was sprayed with the same volume of sterile water as the noninoculated control treatment. Plants were grown in the greenhouse at 20 to 25°C and were covered with plastic bags to maintain humidity on the foliage for 72 h. After 5 days, the foliar symptoms described earlier for the field plants appeared on the leaves, whereas the control plants remained healthy. K. microsticta was reisolated from the leaf spots of all 20 inoculated plants. Leaf streak is the most destructive disease of daylily, and was previously reported in Japan and the United States (Illinois, Kentucky, Mississippi, Louisiana, Pennsylvania, Maryland, Virginia, Florida, North Carolina, and Georgia) (3). To our knowledge, this is the first report of the disease caused by K. microsticta in China. References: (1) D. E. L. Cooke et al. Mycol. Res. 101:667, 1997. (2) E. J. Hermanides-Nijhof. Stud. Mycol. 15:153, 1977. (3) R. M. Leahy et al. Plant Pathology Circular No. 376, 1996. (4) P. Zalar et al. Stud. Mycol. 61:21, 2008.

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First Report of a Leaf Spot Caused by Alternaria compacta on Hydrangea anomala subsp. petiolaris in Italy

Plant Disease ◽

10.1094/pdis-92-1-0173c ◽

2008 ◽

Vol 92 (1) ◽

pp. 173-173 ◽

Cited By ~ 2

Author(s):

A. Garibaldi ◽

D. Bertetti ◽

M. L. Gullino

Keyword(s):

Morphological Characteristics ◽

The United States ◽

Plant Diseases ◽

Spore Suspension ◽

Pathogenicity Test ◽

Aesthetic Quality ◽

First Report ◽

Plastic Bags ◽

Alternaria Sp ◽

The Aesthetic

Hydrangea anomala subsp. petiolaris (synonym H. petiolaris and H. scandens), also known as climbing hydrangea, is cultivated as an ornamental for landscaping in parks and gardens. This species, belonging to the Hydrangeaceae and native to the woodlands of Japan and coastal China, is widely appreciated for its abundant, creamy white flowers with a sweet aroma, particularly in shade gardens. During the summer of 2006, extensive necroses were observed on leaves and young stems of 3-year-old plants grown outdoors in several gardens of Piedmont of northern Italy. In many cases, on the upper side of the leaves, necrotic spots (4 to 10 mm in diameter) turned progressively black. Lesions often coalesced, generating larger (2 to 6 cm in diameter) necrotic areas. Necroses initially developed mainly at leaf margins and near petioles, and severely affected plants were defoliated. Infected plants rarely died, but the presence of lesions reduced the aesthetic quality and subsequently the commercial value. The disease occurred on 50 of 100 plants. A fungus was consistently isolated from infected leaves on potato dextrose agar (PDA) and identified on the basis of its morphological characteristics as an Alternaria sp. Conidia were dark gray, multicellular, clavate to pear shaped, measuring 23 to 54 × 10 to 13 μm (average 38 × 12 μm), with five longitudinal crosswalls and a relatively short apical beak. DNA was extracted with a Nucleospin Plant Kit (Macherey Nagel, Brockville, ON, Canada) and PCR was carried out with ITS 6/ITS 4 primer (2). A 557-bp PCR product was sequenced, and a BLASTn search (1) confirmed that the sequence corresponded to Alternaria compacta (99% homology). The nucleotide sequence has been assigned GenBank Accession No. EU 128529. Pathogenicity tests were performed by spraying leaves of healthy 1-year-old potted H. anomala plants with an aqueous 105 CFU/ml spore suspension. The inoculum was obtained from cultures of the fungus grown on sterilized host leaves placed on PDA for 20 days in light/dark at 23 ± 1°C. Plants sprayed only with water served as controls. Five plants were used for each treatment. Plants were covered with plastic bags for 3 days after inoculation and maintained between 12 and 22°C. Lesions developed on leaves 8 days after inoculation with the spore suspension, whereas control plants remained healthy. A. compacta was consistently reisolated from these lesions. The pathogenicity test was repeated twice. The presence of an Alternaria sp. on H. macrophylla was reported in the United States (3), whereas A. hortensiae was observed in Spain on H. hortensis. Recently, A. alternata belonging to the alternata group was reported on H. macrophylla in Italy (4). This is, to our knowledge, the first report of A. compacta on H anomala subsp. petiolaris in Italy. References: (1) S. F. Altschud et al. Nucleic Acids Res. 25:3389, 1997. (2) D. E. L. Cooke and J. M. Duncan. Mycol. Res. 101:667, 1997. (3) M. L. Daughtrey et al. Page 9 in: Compendium of Flowering Potted Plant Diseases. American Phytopathological Society. St. Paul, MN, 1995. (4) A. Garibaldi et al. Plant Dis. 91:767, 2007.

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First Report of Rust Caused by Pucciniastrum circaeae on Fuchsia × hybrida in Italy

Plant Disease ◽

10.1094/pdis-11-11-0976-pdn ◽

2012 ◽

Vol 96 (4) ◽

pp. 588-588 ◽

Cited By ~ 1

Author(s):

A. Garibaldi ◽

G. Gilardi ◽

G. Ortu ◽

M. L. Gullino

Keyword(s):

Phylogenetic Trees ◽

Aqueous Suspension ◽

Morphological Characteristics ◽

Pcr Amplification ◽

Signs And Symptoms ◽

The United States ◽

Pathogenicity Test ◽

First Report ◽

Potted Plants ◽

Plastic Bags

Fuchsia is a genus of flowering plants that is native to South America and New Zealand and belongs to the family Onagraceae. In September 2011, 2-year-old potted plants of Fuchsia × hybrida, cv. Citation, in a garden located near Biella (northern Italy) showed signs and symptoms of a previously unknown disease. Typically, infected plants showed leaf chlorosis followed by the appearance of necrosis on the adaxial leaf surfaces, while the abaxial surfaces showed orange uredinia irregularly distributed. As the disease progressed, infected leaves turned yellow and wilted. Affected plants showed a progressive phylloptosis and also flowering was negatively affected. Urediniospores were globose, yellow to orange, and measured 14.6 to 25.9 (average 19.6) μm. Teliospores were not observed. Morphological characteristics of the fungus corresponded to those of the genus Pucciniastrum. DNA extraction and PCR amplification were carried out with Terra PCR Direct Polymerase Mix (Clontech, Saint Germain-en-Laye, France) and primers ITS1/ITS4 (4). A 700-bp PCR product was sequenced and a BLASTn search (1) confirmed that the sequence corresponded with a 96% identity to Pucciniastrum circaeae. The nucleotide sequence has been assigned the GenBank Accession No. JQ029688. Pathogenicity tests were performed by spraying leaves of healthy 1-year-old potted Fuchsia × hybrida plants with an aqueous suspension of 1 × 103 urediniospores ml–1. The inoculum was obtained from infected leaves. Plants sprayed only with water served as controls. Three plants were used for each treatment. Plants were covered with plastic bags for 4 days after inoculation and maintained outdoors at temperatures ranging between 18 and 25°C. Lesions developed on leaves 20 days after inoculation with the urediniospore suspension, showing the same symptoms as the original plants, whereas control plants remained healthy. The organism that was recovered from the lesions after inoculation was the same as the one obtained from the diseased plants. The pathogenicity test was carried out twice with similar results. The presence of P. fuchsiae, later identified as P. epilobii, was repeatedly reported in the United States (3). P. epilobii and P. circaeae have closely related hosts and morphologically similar urediniospores. These species were reported to form a single group in molecular phylogenetic trees (2). This is, to our knowledge, the first report of P. circaeae on Fuchsia × hybrida in Italy. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997 (2) Y. M. Liang et al. Mycoscience 47:137, 2006. (3) L. B. Loring and L. F. Roth. Plant Dis. Rep. 48:99, 1964. (4) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990.

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First Report of Canker on Pecan (Carya cathayensis) Caused by Botryosphaeria dothidea in China

Plant Disease ◽

10.1094/pdis-05-11-0457 ◽

2011 ◽

Vol 95 (10) ◽

pp. 1319-1319 ◽

Cited By ~ 8

Author(s):

C. Q. Zhang ◽

B. C. Xu

Keyword(s):

Morphological Characteristics ◽

Its Region ◽

Distilled Water ◽

Botryosphaeria Dothidea ◽

Tissue Samples ◽

First Report ◽

Cornell University ◽

Plastic Bags ◽

Management Measures ◽

Carya Cathayensis

In the late 1990s, sporadic occurrence of Botryosphaeria canker on Carya cathayensis was recorded in Zhejiang Province, China. From 2005 to 2009, nearly 90% of orchards in Zhejiang and Anhui provinces were seriously affected by this disease. Symptoms were similar to those of canker of C. illinoinensis (2); small, elliptical lesions that developed on the bark at points of infection and then enlarged to form large, sunken, elongated cankers. The cankers coalesced, forming large diffuse areas of blighted tissue, which turned black. Tissue samples from the margin of trunk lesions from 35 different diseased trees from five counties were surface sterilized with 1.5% sodium hypochlorite for 3 min, plated on 2% potato dextrose agar (PDA), and incubated at 25°C in the dark for 1 week. Gray-black mycelia and colorless, aseptate, thin-walled conidia, 17.3 ± 0.8 long and 4.5 ± 0.5 μm wide, were produced. On the basis of these morphological characteristics, the fungus was identified as Botryosphaeria dothidea (Moug. ex Fr.) Ces. & De Not (1). The internal transcribed spacer (ITS) region was amplified with primers ITS1/ITS4 from DNA extracted from mycelium produced on PDA and was recorded as GenBank Accession Nos. HQ731442 and HQ731443. The results of BLAST showed that it had more than 98% similarity to records for B. dothidea. Uninfected twigs and stems of C. cathayensis were wounded with a scalpel and then sprayed with a conidia suspension of 106 conidia per ml in distilled water as inoculum or distilled water only to provide an noninoculated control, wrapped in plastic bags to retain moisture, and incubated for 48 h. For each isolate, five twigs and stems per tree and a total of 10 trees were inoculated. After 2 weeks, 14 of 15 isolates caused lesions on inoculated stems and twigs, whereas no symptoms developed on the noninoculated controls. Cultures isolated from lesions and cultured on PDA exhibited morphological characteristics identical to those of B. dothidea, confirming completion of Koch's postulates. Currently, the distribution of Botryosphaeria canker of C. cathayensis is confined to Zhejiang and Anhui provinces. The identification of the pathogen now allows for appropriate forest management measures. To our knowledge, this is the first report of Botryosphaeria canker of pecan (C. cathayensis) in China. References: (1) S. Denman et al. Stud. Mycol. 45:129, 2000. (2) W. A. Sinclair and H. H. Lyon. Diseases of Trees and Shrubs. 2nd ed. Cornell University Press, Ithaca, NY, 2005.

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