Brown Margins Research Articles

First Report of Leaf Blight Caused by Phomopsis ipomoeae-batatas on Sweet Potato in Korea.

Ipomoea batatas (L.) Lam., belonging to the Convolvulaceae, is widely cultivated and used as an industrial resource as well as for food and feed worldwide (2). In September 2010, an unknown leaf blight was observed on leaves in Hoengseong County and Jecheon City in Korea. Symptoms were mostly observed in older leaves as cream to tan-brown lesions surrounded by purplish brown-to-dark brown margin. Each lesion was circular to irregular, not exceeding 10 mm, but coalesced to form larger lesions. Necrotic tissue fell out giving rise to shot-holes. A number of black pycnidia were present in the lesions of diseased leaves. The same symptoms were observed at several localities in Korea during 2010 and 2011 seasons. The voucher specimens (n = 5) were preserved in the Korea University Herbarium (KUS). Two isolates were obtained from the two samples (KUS-F25274 and KUS-F25361) and deposited in the Korean Agricultural Culture Collection (Accession Nos. KACC45680 and KACC45702). Pycnidia were amphigenous, but mostly epigenous, scattered, dark brown-to-rusty brown, globose, embedded in host tissue or partly erumpent, 110 to 170 μm in diameter, and with an ostiole of 25 to 40 μm in diameter. Alpha conidia were aseptate, lageniform, biguttulate, hyaline, and 5.5 to 8.0 × 3.5 to 4.5 μm. Beta conidia were absent. Based on the morphological characteristics, the fungus was consistent with Phomopsis ipomoeae-batatas Punith. (1,3). Preliminary identification of the fungal isolate was confirmed by molecular data. Genomic DNA was extracted from the two isolates. The D1/D2 region of 28S rDNA was amplified using the primers LROR and LR7, and sequenced. The resulting sequences of the two isolates were identical to each other, and were deposited in GenBank (Accession Nos. JX157848 and JX157849). A BLAST search showed that there was no matching sequence of P. ipomoeae-batatas. Therefore, these were the first 28S sequences for the species submitted to GenBank. The present sequences showed >98% similarity with 24 entries of Phomopsis spp. and Diaporthe spp. (teleomorph of Phomopsis spp.), indicating their close phylogenetic relationship. Pathogenicity was tested by spraying leaves of three potted plants with a conidial suspension (2 × 106 conidia/ml), which was harvested from a 3-week-old culture on potato dextrose agar. Control leaves were sprayed with sterile water. The plants were placed in a dew chamber at 24°C in darkness and continuous dew for the first 24 h and then moved to a greenhouse bench. After 10 days, leaf blight symptoms that were identical to those observed in the field started to develop on the leaves inoculated with the fungus. No symptoms were observed on control plants. P. ipomoeae-batatas was reisolated from the lesions of inoculated plants, confirming Koch's postulates. Occurrence of leaf blight caused by P. ipomoeae-batatas on sweet potato has been reported in many countries (1,3). To our knowledge, this is the first report of the disease in Korea. The economic losses are of minor importance, because the disease is mostly present toward the end of growing season; however, attention must be paid considering that the pathogen may reduce the quality of vines used as fodder.

First Report of Sarocladium oryzae Causing Sheath Rot on Rice (Oryza sativa) in Western Australia.

Rice (Oryza sativa L.) has been grown in the Ord River Irrigation Area (ORIA) in northern Western Australia since 1960. In 2011, a sheath rot of rice was observed in the ORIA. Symptoms were variable, appearing as either (i) oblong pale to dark brown lesions up to 3 cm length, (ii) lesions with pale grey/brown centers and with dark brown margins, or (iii) diffuse dark or reddish brown streaks along the sheath. Lesions enlarged and coalesced, often covering the majority of the leaf sheath, disrupting panicle emergence. Isolations from small pieces of infested tissues from plants showing sheath rot symptoms were made onto water agar, subcultured onto potato dextrose agar, cultures maintained at 20°C, and a representative culture lodged both in the Western Australian Culture Collection maintained at the Department of Agriculture and Food Western Australia (as WAC 13481) and in the culture collection located at the DAFF Plant Pathology Herbarium (as BRIP 54763). Amplification of the internal transcribed spacer (ITS)1 and (ITS)2 regions flanking the 5.8S rRNA gene were carried out with universal primers ITS1 and ITS4 according to the published protocol (4). The DNA PCR products from a single isolate were sequenced and BLAST analyses used to compare sequences with those in GenBank. The sequence had 99% nucleotide identity with the corresponding sequence in GenBank for Sarocladium oryzae (Sawada) W. Gams & D. Hawksworth. Isolates showed morphological (e.g., conidiophore and conidia characteristics) (2) and molecular (1) similarities with S. oryzae as described in other reports. The relevant sequence information for a representative isolate was lodged in GenBank (GenBank Accession No. JQ965668). Spores of S. oryzae were produced on rice agar under "black light" at 22°C to induce sporulation over 4 weeks. Under conditions of 30/28°C (day/night), 14/12 h (light/dark), rice cv. Quest, grown for 11 weeks until plants reached the tillering stage, was inoculated by spraying a suspension 5 × 107 spores/ml of the same single isolate onto foliage until runoff occurred. Inoculated plants were placed under a dark plastic cover for 72 h to maximize humidity levels around leaves and subsequently maintained under >90% relative humidity conditions. Symptoms of sheath rot as described in (i) and (ii) above appeared by 14 days after inoculation, with lesions up to 23 cm long by 15 days post-inoculation. Severe disease prevented young panicles from emerging. Infection studies were successfully repeated and S. oryzae was reisolated from leaf lesions 1 week after lesion appearance. No disease was observed on water-inoculated control rice plants. There have been records of S. oryzae on rice in New South Wales in the early 1980s (3) and in 2006 to 2007 (Australian Plant Pest Database), but to our knowledge, this is the first report of this pathogen in Western Australia.

First Report of Dollar Spot Caused by Sclerotinia homoeocarpa on Agrostis stolonifera in North Dakota.

Dollar spot disease is a major concern for golf courses nationwide, resulting in poor turf quality and significant damage to playing surfaces. To manage this disease effectively, fungicides need to be applied regularly. This management strategy represents a significant cost to turfgrass managers and may impact the economics of the industry in North Dakota. In the summer of 2011, small, circular, sunken brown patches of dead turf approximately 5 cm in diameter and resembling dollar spot disease were observed on a creeping bentgrass (Agrostis stolonifera L.) variety trial at the North Dakota State University Agricultural Experiment Station in Fargo, ND. Fresh individual leaf specimens with distinct lesions having straw colored centers and reddish brown margins were collected. Leaves were surface disinfected in a 0.05% sodium chloride solution for 60 s, rinsed three times in sterile distilled water, then placed onto potato dextrose agar (PDA). Three isolates were obtained from the disease infested leaves with similar morphology to that described for Sclerotinia homoeocarpa F.T. Bennett (1). Fungal colonies were initially colorless followed by the development of sparse white columnar aerial mycelia with cinnamon colored bases. Hyphae were 5 to 8 μm wide and thin walled with dense granular contents and septations at irregular intervals. Fourteen days after culturing, dark brown to black mycelial stroma developed. A single representative isolate was selected to conduct inoculations. Inoculum was produced by placing six 5-mm-diameter plugs of PDA with actively growing mycelium into an Erlenmeyer flask with 40 g of sterile millet seed. The inoculum was incubated for 14 days at ambient temperature (20 to 25°C). Three creeping bentgrass cultivars, Crenshaw, Declaration, and L-93, were inoculated (two pots per cultivar). Following inoculation, the pots were misted with water, sealed in separate plastic bags, and placed in the dark for 48 h. For the next 5 days, plants were placed for 8 h outside of bags on a bench with full spectrum fluorescent bulbs, followed by 16 h in plastic bags in the dark. Finally, pots were placed on a bench for 48 h. Signs and symptoms of S. homoeocarpa developed on all pots, whereas the controls remained asymptomatic. The same fungus was reisolated from grass leaves, satisfying Koch's postulates. To confirm the identity of the fungus, the internal transcribed spacer was amplified using the ITS4 and ITS5 primers (2). The amplicon was sequenced, generating a 549-bp sequence (Accession No. JQ735942) with 100% similarity to sequences of S. homoeocarpa in GenBank (Accession Nos. GQ924924.1, GQ924923.1, and EU123801.1). To our knowledge, this is the first confirmed report of dollar spot in North Dakota.

First Report of a Fusarium sp. and Its Vector Tea Shot Hole Borer (Euwallacea fornicatus) Causing Fusarium Dieback on Avocado in California.

Per capita consumption of avocado in the United States has nearly doubled between 2000 and 2010. The California avocado industry supplies almost 40% of U.S. demand and the remaining 60% is supplied by imports from Latin America and New Zealand. The Tea Shot Hole Borer (TSHB) is an ambrosia beetle from Asia that forms a symbiosis with a new, yet undescribed Fusarium sp. and is a serious problem for the Israeli avocado industry (3). The beetle also causes severe damage on the branches of tea (Camelia sinensis) in Sri Lanka and India (1). In California, TSHB was first reported on black locust (Robinia pseudoacacia) in 2003, but there are no records of fungal damage (4). In 2012, nine backyard avocado trees (cvs. Hass, Bacon, Fuerte, and Nabal) exhibiting branch dieback were observed throughout the residential neighborhoods of South Gate, Downey, and Pico Rivera in Los Angeles County. Upon inspection, symptoms of white powdery exudate, either dry or surrounded by wet discoloration of the outer bark in association with a single beetle exit hole, were found on the trunk and main branches of the tree. Examination of the cortex and wood under the exit hole revealed brown discolored necrosis. The TSHB was also found within galleries that were 1 to 4 cm long going against the grain. Symptomatic cortex and sapwood tissues were plated onto potato dextrose agar amended with 0.01% tetracycline (PDA-tet). The TSHB was dissected and plated onto PDA-tet after surface disinfestation following methods described by Kajimura and Hijii (2). After 5 days of incubation at room temperature, regular fungal colonies with aerial mycelia and reddish brown margins were produced. Single spore isolations were used to establish pure culture of the fungus. Fifty conidia were hyaline, clavate with a rounded apex, and initially aseptate (4.1 to 12.0 × 2.4 to 4.1 μm) becoming one- to three-septate (7.6 to 15.1 × 2.8 to 4.5 μm, 9.2 to 17.2 × 3.4 to 4.8 μm, and 13.5 to 17.6 × 4.3 to 4.7 μm, respectively). Identity of the fungal isolates was determined by amplification of the rDNA genes with primers ITS4/5 and EF1/2, respectively. Sequences were deposited into GenBank under Accession Nos. JQ723753, JQ723760, JQ723756, and JQ723763. A BLASTn search revealed 100% similarity to Fusarium sp. (Accession Nos. JQ038020 and JQ038013). Detached green shoots of healthy 1-year-old avocado were wounded to a depth of 1 to 2 mm and 5-mm mycelial plugs from 5-day-old cultures (UCR 1781 and UCR 1837) were placed mycelial side down onto the freshly wounded surfaces and then wrapped with Parafilm. Control shoots were inoculated with sterile agar plugs and five replicates per treatment were used. Shoots were incubated at 25 ± 1°C in moist chambers for 3 weeks. Lesions were observed on all inoculated shoots except for the control. Mean lesion lengths were 10.7 and 12.8 cm for UCR1781 and UCR1837, respectively, and were significantly different (P ≤ 0.05) from the control. Both isolates were reisolated from 100% of symptomatic tissues of inoculated shoots to complete Koch's postulates. This experiment was conducted twice and similar results were obtained. To our knowledge, this is the first report of Fusarium sp. and its vector E. fornicatus causing Fusarium dieback on Avocado in California.

Rhynchosporium commune: a persistent threat to barley cultivation.

Rhynchosporium commune is an anamorphic Ascomycete closely related to the teleomorph Helotiales genera Oculimacula and Pyrenopeziza. Rhynchosporium commune causes scald-like lesions on leaves, leaf sheaths and ears. Early symptoms are generally pale grey oval lesions. With time, the lesions acquire a dark brown margin with the centre of the lesion remaining pale green or pale brown. Lesions often merge to form large areas around which leaf yellowing is common. Infection frequently occurs in the leaf axil, which can lead to chlorosis and eventual death of the leaf. Rhynchosporium commune is seed borne, but the importance of this phase of the disease is not fully understood. Debris from previous crops and volunteers, infected from the stubble from previous crops, are considered to be the most important sources of the disease. Autumn-sown crops can become infected very soon after sowing. Secondary spread of disease occurs mainly through splash dispersal of conidia from infected leaves. Rainfall at the stem extension growth stage is the major environmental factor in epidemic development. DETECTION AND QUANTIFICATION: Rhynchosporium commune produces unique beak-shaped, one-septate spores both on leaves and in culture. The development of a specific polymerase chain reaction (PCR) and, more recently, quantitative PCR (qPCR) has allowed the identification of asymptomatic infection in seeds and during the growing season. The main measure for the control of R. commune is the use of fungicides with different modes of action, in combination with the use of resistant cultivars. However, this is constantly under review because of the ability of the pathogen to adapt to host plant resistance and to develop fungicide resistance.

First Report of Fusarium proliferatum Causing Fruit Rot of Winter Jujube (Zizyphus jujuba) in Storage in China.

Winter jujube, Zizyphus jujuba Mill., is a Chinese crop with fruit that has an extremely high nutritional value (4). In early November 2010, a severe fruit rot affecting ~20% of 1,000 kg of winter jujube fruit was observed in a storehouse in Zhengzhou, Henan province, China. The same fruit rot symptoms were found in two supermarkets in Zhengzhou in late November 2010 in ~10% of 100 kg of fruit in one supermarket and 25% of 50 kg of fruit in the other. Symptoms first appeared as small, round, pale yellow brown lesions on the fruits, 1 to 3 mm in diameter, then developed into 5- to 10-mm, sunken, brown spots, each with a pale brown margin. Three Fusarium isolates (DZF001 to DZF003) showing similar morphological characteristics were isolated from three specimens (collected from one storehouse and two supermarkets) by surface sterilizing small pieces of necrotic fruit tissue for 1 min in 2% NaOCl, washing the tissue pieces three times with sterile distilled water, and plating the pieces on potato dextrose agar (PDA). Fungal colonies for each isolate were white to light pink, and the adaxial side of each culture was pale yellow. Macroconidia were produced in pale orange sporodochia and were slender, relatively straight, three to five septa, 29.0 to 55.2 × 2.5 to 4.0 μm, with a curved apical cell and a poorly developed basal cell. Microconidia were produced in chains or false heads on synthetic nutrient-poor agar, clavate with a planar base, aseptate, and 4.5 to 8.0 × 2.5 to 3.5 μm. Conidiophores terminated in verticils of two to three phialides or monophialides. Chlamydospores were absent. The cultural and morphological characteristics were similar to those of Fusarium proliferatum (1,2). The identity of the three fungal isolates was confirmed to be F. proliferatum by DNA sequencing of the internal transcribed spacer (ITS) rDNA region (GenBank Accession Nos. JN889713 to JN889715), which were 99 to 100% homologous to those of other F. proliferatum isolates (GU066714, HQ113948, and GU363955); and the elongation factor 1-alpha (EF-1a) gene (JN889713 to JN889715), which was 99% homologous to those of other F. proliferatum isolates (FJ538244, FJ895277, and GQ848536) (3). Pathogenicity tests were conducted on 20 winter jujube fruits using a mycelial plug harvested from the periphery of a 7-day-old colony of strain DZF001, and placed on the surface of the fruit after the inoculated area of the fruit had been surface sterilized with 75% ethanol for 2 min; an equal number of fresh winter jujube fruits treated with non-colonized plugs of PDA served as the control treatment. Each jujube fruit was pricked three times with an insect needle to create three holes close together before inoculation with an agar plug. Each fruit was then enclosed in a clear plastic box with a cup of sterile distilled water to maintain high relative humidity, and held at 25°C. Symptoms similar to those originally observed on the naturally infected fruit were observed 3 days after inoculation, and the same fungus was reisolated from each of the symptomatic fruits; control fruits remained asymptomatic and no fungus was isolated from the control fruit. Koch's postulates were repeated three times with the same results. To our knowledge, this is the first report of F. proliferatum causing rot of winter jujube fruit in China.

First Report of Phoma herbarum on Tedera (Bituminaria bituminosa var. albomarginata) in Australia.

Tedera (Bituminaria bituminosa (L.) C.H. Stirton var. albomarginata) has been successfully established across the mixed-farming (wheat-sheep) region of Western Australia because this species has remarkable drought tolerance and can survive the dry-summer period with strong retention of green leaf. A leaf spot symptom involving pale brown lesions with distinct dark brown margins had been observed in genetic evaluation plots of tedera at Medina and Mount Barker, Western Australia, and a Phoma sp. was isolated. Single-spore isolations of a typical Phoma sp. isolate were made onto potato dextrose agar and maintained at 20°C, and a representative culture has been lodged in the Western Australian Culture Collection Herbarium maintained at the Department of Agriculture and Food Western Australia (Accession No. WAC13435). Amplification of the internal transcribed spacer (ITS) 1 and ITS2 regions flanking the 5.8S rRNA gene were carried out with universal primers ITS1 and ITS4 according to published protocol (3). The DNA PCR products were sequenced and BLAST analyses was used to compare sequences with those in GenBank. The sequence had 99% nucleotide identity with the corresponding sequence in GenBank for Phoma herbarum. Isolates also showed morphological (e.g., 1) and molecular (e.g., 2) similarities with P. herbarum as described in other reports. The relevant sequence information for a representative isolate has been lodged in GenBank (Accession No. JQ282910). A conidial suspension of 107 conidia ml-1 from a single-spore culture was spray inoculated onto foliage of 6-week-old tedera plants maintained under >90% relative humidity conditions for 72-h postinoculation. Symptoms evident by 10 days postinoculation consisted of pale brown lesions, mostly 1.5 to 4 mm in diameter, which developed a distinct, dark brown margin. Occasional lesions also showed a distinct chlorotic halo extending 1 to 1.5 mm outside the boundary of the lesion. Infection studies were successfully repeated twice and P. herbarum was readily reisolated from infected foliage. No disease was observed on and no P. herbarum were isolated from water-inoculated control plants. Except for a recent published report of P. herbarum on field pea (Pisum sativum L.) (2), this pathogen has only been noted in the Australian Plant Pest Database as occurring on lucerne (Medicago sativa L.) and soybean (Glycine max (L.) Merr.) in Western Australia in 1985 and on a Protea sp. in 1991. To our knowledge, this is the first published report of P. herbarum as a pathogen on tedera in Australia or elsewhere. That P. herbarum occurs on other hosts in Australia and has a wide host range elsewhere together suggest its potential to be a pathogen on a wider range of host genera and species.

First Report of Stem and Foliar Blight of Sunflower Caused by Alternariaster helianthi in Louisiana.

During the fall of 2009, sunflower (Helianthus annuus L.) planted at the LSU AgCenter's Burden Center in Baton Rouge, LA exhibited severe stem and foliar blight symptoms. Symptoms on stems and petioles included elongated, slightly sunken lesions with dark brown margins. Leaf symptoms included irregular to circular, dark brown lesions with white centers and surrounded by a yellow halo. Several spots often coalesced to form large, blighted areas, and severely affected leaves turned yellow, followed by defoliation. The corolla and calyx exhibited similar lesions except for the yellow halo. Disease developed rapidly and the whole (100% disease incidence) field was blighted within a week following a rain (4 mm). Infected leaf and stem tissue was surface disinfested and plated on ¼-strength potato dextrose agar (PDA). Both leaf and stem tissue consistently produced dark olivaceous-to-black fungal colonies at room temperature under 12 h of fluorescent light per day. Conidia were 53 to 128 × 10 to 26 μm, borne singly on the conidiophores, hyaline to dark olivaceous, cylindrical, rounded at both ends, and with 6 to 10 transverse and 0 to 2 longitudinal septa. Conidiophores were single, unbranched, septate, hyaline to dark olivaceous, and measured 77 to 128 × 7 to 13 μm. Morphologically, the fungus was identified as Alternariaster helianthi (Hansf.) E.G. Simmons (= Alternaria helianthi [Hansf.] Tubaki & Nishih) (1). A single-spore isolate (PDC-4291) was obtained from the original culture and DNA from this isolate was extracted with a DNeasy Plant Mini Kit (Qiagen Inc., Valencia, CA). Primers ITS1 and ITS4 were used to amplify and sequence the internal transcribed spacer regions 1 and 2, and NCBI blast analysis of the 552-bp sequence (GenBank Accession No. JN208925) resulted in 100% homology with Alternaria helianthi isolated from sunflower infected with leaf spot and blight disease in India (GenBank Accession No. DQ156343). Pathogenicity was determined by inoculating 20 potted sunflower plants (Full Sun Improved TD, Fred C. Gloeckner and Company, Inc., Harrison, NY) with conidia from a 2-week-old culture of isolate PDC-4291. Each plant was sprayed with 25 ml of suspension containing 106 conidia/ml. Twenty control plants were sprayed with 25 ml of sterile distilled water. Inoculated and control plants were covered with plastic bags and maintained in a greenhouse at 28 ± 2°C. Plastic bags were removed 72 h after inoculation. Leaf spots similar to the original symptoms appeared on all 20 inoculated plants 5 days after inoculation. A few stem lesions were observed on 13 plants. Two weeks after inoculation, infected leaves turned yellow and blighted. Alternariaster helianthi (= Alternaria helianthi) was reisolated from the leaf spots and stem lesions. No symptoms developed on any of the 20 control plants. On the basis of morphology and sequence data, this pathogen was identified as A. helianthi, and to our knowledge, this is the first report of sunflower stem and foliar blight caused by A. helianthi in Louisiana. In Louisiana, sunflower is a popular ornamental that is grown in landscapes and gardens and by commercial flower growers who grow it for cut flower arrangements. Louisiana's hot, humid weather is ideal for disease development, which may discourage gardeners and commercial growers from planting sunflower. Reference: (1) E. G. Simmons. Alternaria: An Identification Manual. CBS Fungal Biodiversity Center, Utrecht, the Netherlands, 2007.

First Report of Leaf Spot Caused by Alternaria longipes on Atractylodes macrocephala in China.

Atractylodes macrocephala Koidz. is a perennial herb that has been used in Chinese herbal medicine for centuries. During the summer of 2011, leaf spots were observed on leaves of A. macrocephala in Panan County of Zhejiang Province, China. Approximately 40% of the plants surveyed showed severe symptoms of leaf spot. At the initial stage of the infection, small, light brown spots appeared on the leaves that gradually became semicircular, oval, or irregular-shaped with dark brown or black centers surrounded by brown or light brown margins. The lesions enlarged and coalesced to form large areas of necrosis on leaves until entire leaves died. Eight fungal isolates were obtained from diseased A. macrocephala leaves by a tissue isolation method (1). Isolates were cultured on potato dextrose agar (PDA) plates at 25°C in darkness. Colonies on PDA were initially white and became grayish brown over time. Conidiophores were light brown with one or a few regular septa, mostly unbranched. Conidia were obclavate, dark brown, with three to eight transverse and zero to two longitudinal or oblique septa, and on average measured 35.1 (20 to 53) × 9.8 (5.8 to 13.3) μm (n = 20). The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS1F/ITS4 and sequenced (GenBank Accession No. JQ004404). The ITS sequence had 99% identity over 545 bp with Alternaria longipes (Ellis & Everh.) E. W. Mason (GenBank Accession No. AY278835), a fungal pathogen reported to cause leaf spot on Smilax china in China (3). To further identify the fungus, we chose the Alternaria allergen gene (Alt a 1 gene), which aids in identifying species of Alternaria (2). Amplification of the Alt a 1 gene was conducted using primers Alt-for/Alt-rev and sequenced (GenBank Accession No. JQ004405). Sequence comparisons showed there was 97% sequence identity with Alternaria longipes (GenBank Accession No. AY563304). Pathogenicity tests were performed on detached healthy A. macrocephala leaves. Nine leaves were inoculated by placing a PDA plug (0.5 cm2) of mycelia on upper surfaces of the leaves. Another nine leaves treated with sterile PDA plugs served as a control. Leaves were incubated in three petri dishes with a 12-h photoperiod at 25°C and 95% relative humidity. After 7 days, the symptoms described above were observed on all inoculated leaves, whereas no symptoms developed on control leaves. Reisolation of the fungus from symptomatic leaf tissues on PDA confirmed that the causal agent was Alternaria longipes. This pathogenicity test was performed three times. The genus Alternaria is ubiquitous and includes both plant pathogenic and saprophytic species that may cause leaf spot and blight on numerous plants (3,4), but to our knowledge, our research demonstrated this is the first report of leaf spot on A. macrocephalae caused by Alternaria longipes in China.

First Report of Postharvest Fruit Rot in Avocado (Persea americana) Caused by Lasiodiplodia theobromae in Italy.

Avocado (Persea americana Mill.) is grown in some areas of southern Italy. In spring 2011, a previously unknown rot was observed on fruit that was marketed in Torino (northern Italy). The decayed area started from the stalk, appeared irregular and soft, and was surrounded by a dark brown margin. The internal decayed area appeared rotten, brown, and surrounded by bleached tissue. Fragments (approximately 3 mm) were taken from the margin of the internal diseased tissues, cultured on potato dextrose agar (PDA), and incubated at temperatures between 21 and 25°C under alternating conditions of light and dark. Colonies of the fungus initially appeared whitish, later turning mouse gray to black. Mature mycelium was septate and produced a dark pigment. The fungus, grown on oat agar (2) and incubated at temperatures between 21 and 25°C under alternating light and darkness, produced grayish colonies with a fluffy aerial mycelium that became dark with age and produced black pigments. After 18 days of incubation, such colonies produced pycnidia aggregated into stromatic masses, emerging from decayed tissues, and up to 3 to 4 mm in diameter. Conidia produced in the pycnidia were initially unicellular, hyaline, granulose, ovoid to ellipsoidal, and measured 20.8 to 26.9 × 12.5 to 16.1 (average 24.4 × 13.5) μm. After 7 days, mature conidia became darker, uniseptate, and longitudinally striate. Paraphyses produced within the tissues of pycnidia were hyaline, cylindrical, nonseptate, and up to 63 μm long. Morphological characteristics of mycelia, pycnidia, and conidia observed with a light microscope permitted identify of the fungus as Lasiodiplodia theobromae (3). The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS1/ITS4 and sequenced. BLAST analysis (1) of the 488-bp segment showed a 100% similarity with the corresponding sequence (GenBank Accession No. GQ502453) of L. theobromae Pat. Griffon & Maubl. The nucleotide sequence of the strain used for pathogenicity tests was submitted to GenBank (Accession No. JN849098). Pathogenicity tests were performed by inoculating 10 avocado fruits after surface disinfesting in 1% sodium hypochlorite and then wounding. Mycelial disks (8 mm in diameter) obtained from PDA cultures of one strain were placed on wounds. Ten control fruits were inoculated with plain PDA. Fruits were incubated at 15 ± 1°C. The first symptoms developed 4 days after the artificial inoculation. After 7 days, the rot was evident and L. theobromae was consistently reisolated. Noninoculated fruit remained healthy. The pathogenicity test was performed twice. To our knowledge, this is the first report of the presence of L. theobromae causing postharvest fruit rot on avocado in Italy, as well as in Europe. The occurrence of postharvest fruit rot on avocado caused by L. theobromae was described in many avocado-producing areas such as the United States (4), South Africa, and Israel. In Italy, the economic importance of avocado cultivation is currently limited.

First Asian Report of Leaf Spot of Ambrosia trifida Caused by Septoria epambrosiae.

Ambrosia trifida L., known as giant ragweed, is native to North America and was introduced in Korea in the 1970s (4). It is now widely naturalized, and since 1999, has been designated as one of 11 most 'harmful nonindigenous plants' by the Korean Ministry of Environment because of its adverse effects on native plants. Various strategies to eradicate this noxious weed have been unsuccessful (4). In June 2008, leaf spot symptoms on this weed were found in Inje, Korea. Hundreds of giant ragweed growing along stream banks contained leaf spots with leaf yellowing and premature defoliation. Leaf lesions were 1 to 5 mm in diameter, angular to irregular, dark brown without a distinct margin, later becoming pallid with a brown margin. Between 2008 and 2011, the authors observed the same symptoms in Dongducheon, Yangku, Namyangju, and Pocheon, Korea. Voucher specimens have been housed in the herbarium of Korea University. Numerous black pycnidia were formed on the lesion. Pycnidia were amphigenous, globose, dark brown, ostiolate, and measured 80 to 130 μm in diameter. Conidia were filiform, straight to mildly curved, eguttulate, hyaline, 18 to 36 × 1.5 to 2.5 μm, one to three septate, subtruncate at the base, and tapering to a rounded apex. Single-conidial isolations onto potato dextrose agar formed dark grayish colonies. Pycnidia matured after 5 weeks when plates were incubated under fluorescent illumination for 12-h photoperiods at 25°C. On the basis of morphological and cultural characteristics, the fungus was identified as Septoria epambrosiae D.F. Farr (2). Three isolates were deposited in the Korean Agricultural Culture Collection (KACC). Preliminary morphological identification of the fungal isolates was confirmed by molecular data. The internal transcribed spacer (ITS) region of rDNA was amplified using the ITS1/ITS4 primers and sequenced. The resulting sequences of 449 bp obtained from the three isolates were identical to each other. They showed 100% similarity when compared with a sequence of S. epambrosiae (GenBank No. AF279582). The nucleotide sequence of a representative isolate (KACC43850) was deposited in GenBank (No. JN695498). Pathogenicity was confirmed by inoculating the leaves of three seedlings with a conidial suspension (~2 × 105 conidia/ml). Three noninoculated seedlings served as controls. Plants were maintained in a glasshouse at 100% relative humidity for 48 h. After 6 days, typical leaf spots, identical to the one observed in the field, started to develop on the leaves of the inoculated plants. No symptoms were observed on the control plants. The fungus was successfully reisolated from the symptomatic plants, fulfilling Koch's postulates. A leaf spot disease associated with S. epambrosiae has previously been recorded on A. artemisiifolia in Hungary (1-3) and A. trifida in North America (2,3). To our knowledge, this is the first report of S. epambrosiae on giant ragweed in Asia. Because of its potential as a biocontrol agent, further studies are needed.

First Report of Leaf Disease on Cinnamomum subavenium Caused by Colletotrichum fioriniae in China.

Cinnamomum subavenium Miq. (Lauraceae) is a subtropical arbor plant widely distributed in southwest China. It has a long history of cultivation and has been widely used in traditional Chinese medicine, food flavors, and industrial materials. In August 2010, a serious leaf disease was observed on wild Cinnamomum subavenium growing in Gutianshan Nature Reserve, Zhejiang, China. Lesions were approximately 1.0 cm in diameter and the margin of the lesions was light to dark brown and the middle was gray to pale yellowish. Necrotic lesions were surface disinfected with 1% sodium hypochlorite for 1 min and 70% ethanol for 3 min, and isolations were made from lesion edges onto potato dextrose agar (PDA). Three plants were tested and a fungus was consistently isolated from lesions. Colonies of this fungus on PDA were at first gray becoming pinkish gray with age, with salmon pink conidial masses, and the reverse of the colony was pink. The growth rate was 10.82 to 11.95 mm per day (average = 11.58 ± 0.25, n = 6) on PDA at 25°C. Conidia were oblong or cylindrical with acute ends, occasionally guttulate, hyaline, 7.5 to 14.5 × 2.5 to 4.3 μm (average = 11.25 ± 0.5 × 3.4 ± 0.4, n = 30). These characteristics matched the description of Colletotrichum fioriniae (Marcelino & Gouli) R.G. Shivas & Y.P. Tan (2). DNA was extracted from one isolate and the rDNA-internal transcribed spacer (ITS) region was amplified and sequenced using primers ITS1 and ITS4 (1). The ITS sequence of the isolate (GenBank Accession No. JN208890) shared 100% identity to the holotype of C. fioriniae (Accession No. EF464594). The pathogenicity of C. fioriniae on Cinnamomum subavenium was confirmed through inoculation. Three freshly harvested, healthy leaves were washed under running tap water, immersed in 5% sodium hypochlorite for 3 min and 70% ethanol for 1 min, rinsed three times in sterilized water, and finally dried with sterilized tissue paper. Plant leaves were inoculated with a concentration of 2.5 × 106 spores/ml. Sterilized water was used for controls. All the leaves inoculated with C. fioriniae were symptomatic with round to elliptical lesions with a brown margin 14 days postinoculation. The fungus, reisolated from symptomatic leaf tissue, had the same morphological and cultural characteristics of C. fioriniae. Although C. gloeosporioides has been reported from several species in the genus Cinnamomum ( http://nt.ars-grin.gov/fungaldatabases/ ), to our knowledge, this is the first report of leaf disease on Cinnamomum subavenium caused by a Colletotrichum species.

First Report of Dollar Spot Caused by Sclerotinia homoeocarpa on Switchgrass in the United States.

Sclerotinia homoeocarpa causes dollar spot on many grass species; however, it has not been described on switchgrass (Panicum virgatum L.) as a host. In August 2010, bleached, tan-to-straw-colored leaf spots with dark brown-to-reddish brown margins were found in patchy distribution in small field plots of 'Alamo' switchgrass at the East Tennessee Research and Education Center, Knoxville, TN. The plots had been planted to switchgrass for the past 21 years. Disease lesions covered 75 to 80% of leaf tissue per patch and were also evident on stems. To identify the pathogen, center portions of diseased leaves were cut into 20- to 30-cm segments, surface disinfested (95% ethanol for 30 s, 10% bleach for 1 min, and 95% ethanol for 30 s), and dried. Disinfested leaves (5-cm sections that included a leading edge of a lesion) were plated on potato dextrose agar (PDA). Plates were incubated at 22°C. Within 12 h, white, fluffy, aerial mycelium developed. Viewed from above, colonies were tan to cinnamon in color with a dark brown-to-black substratal stroma on and in the agar, which appeared brown as viewed from below the petri dish. No spores were observed. Morphological characteristics of colony and hyphal growth were identical to those of S. homoeocarpa F.T. Bennett (1). Pathogenicity studies were conducted with 6-week-old 'Alamo' switchgrass grown from scarified (2), surface-disinfested seed. Nine (9 × 9-cm2) pots with 18 plants each were inoculated with 20 mycelial plugs (6-mm diameter) per pot, taken from 3-to-5-day-old fungal cultures. Two control pots were inoculated with sterile PDA plugs and subjected to the same conditions. Plugs were placed on leaf surfaces and around the plant crowns. Plants were subjected to high humidity by enclosure in a plastic bag and incubated in a growth chamber at 25/20°C with a 12-h photoperiod. Plastic bags were removed after 48 h. Leaf spots appeared as early as 2 days postinoculation, with full symptoms after 2 weeks for eight of nine replicates. Control plants had no symptoms. The fungus was cultured from leaf spots and stem lesions of inoculated plants as described above. The same disease and fungus were observed, completing Koch's postulates. The internal transcribed spacer (ITS) regions of ribosomal DNA from the original isolate used for inoculation and from the isolate recovered from plants in the pathogenicity assay were amplified with PCR with primers ITS4 and ITS5 (4). PCR amplicons of ~565 bp were sequenced; sequences of amplicons from the original isolate and reisolate were identical and submitted to GenBank (Accession No. HQ850151). The sequence had 99% homology with several S. homoeocarpa isolates in GenBank, including three isolates from buffalograss in Oklahoma (Accession Nos. EU123800, EU123802, and EU123803). The mitochondrial small subunit region was amplified from the original isolate with primers NMS1 and NMS2 (3). The resultant 536-bp fragment was sequenced and submitted to GenBank (Accession No. HQ850152), but no S. homoeocarpa sequences were available for comparison. To our knowledge, this is the first confirmed report of switchgrass as a natural host for S. homoeocarpa, extending the known host range for the pathogen.

Carex dapanshanica sp. nov. (C. sect. Mitratae, Cyperaceae) from Zhejiang, China

Carex dapanshanica X. F. Jin, Y. J. Zhao & Z. L. Chen, a new species of Cyperaceae from Mount Dapan, Zhejiang Province, eastern China is described and illustrated. The new species is morphologically similar to C. chungii C. P. Wang, but differs in having 2 or 3spikes, pistillate scales with brown margins and short‐awned at apex, and glabrous perigynia. Micromorphological photographs of the achenes of C. dapanshanica and C. chungii under SEM (scanning electron microscope) are provided as well.

First Report of Anthracnose on Boehmeria nivea Caused by Colletotrichum higginsianum in China.

Ramie (Boehmeria nivea (L.) Gaud) anthracnose is regarded as one of the most widely spread and devastating diseases of ramie. This disease is most severe during warm and humid conditions. In China, ramie anthracnose is found in approximately 10,000 ha, with yield losses averaging 20% and ranging as high as 55% in some fields (3). In September 2010, typical anthracnose symptoms were observed in cultivated fields near Xianning, HuBei Province, China. Lesions on diseased leaves were initially small, scattered, bluish white, and water soaked. As the disease progressed, irregular spots developed on the leaves and the spots turned gray in the center with a brown margin. The diameter of the lesions was approximately 1 to 3 mm. Initially, lesions on the stems were fusiform and then expanded, causing the stem to break. Leaf and stem tissue adjacent to and including lesions were surface disinfected in 0.1% sodium hypochlorite and then planted on potato dextrose agar (PDA) plus oxalic acid to inhibit bacterial growth. The plates were incubated at 25°C for 3 to 5 days until the appearance of pink spore masses with numerous dense clusters of black setae. On PDA, the fungus initially produced gray colonies with an orange conidial mass and then the colonies turned black after 5 days. Spores were single celled, colorless, straight, oval, obtuse at both ends, 10.0 to 20.0 × 3.0 to 5.0 μm with an average size of 15.8 ± 2.4 × 4.6 ± 0.4 μm, and a length/width ratio of 3.47 ± 0.62. The setae were dark brown, 1 to 3 septa. These morphological traits corresponded to Colletotrichum higginsianum Sacc (1). The ITS1, 5.8S, and ITS2 sequences with primers ITS1 and ITS4 of this fungus (GenBank Accession No. JF830783) were 99% similar to sequences of multiple isolates of C. higginsianum (GenBank Accession Nos. GU935872 and AB042303). In pathogenicity tests, both sides of ramie plant leaves from 10-day-old, 30-cm high plants were sprayed with conidial suspensions (1 × 106 conidia/ml) of a representative fungal isolate. This experiment was repeated three times. Inoculated plants were incubated in an artificial climate chamber with a 12-h photoperiod at 25 to 28°C and a relative humidity of 90%. Three days after inoculation, brown spots and water-soaked lesions were observed on all inoculated leaves, but no symptoms were seen on water-treated control plants. Koch's postulates were fulfilled by the reisolation of C. higginsianum from diseased leaves. C. higginsianum is known to cause anthracnose leaf spot disease on many cultivars of Brassica and Raphanus spp., but there have been no reports on it causing ramie anthracnose. C. boehmeriae Sawada and C. gloeosporioides Penz are known to be the agents of ramie anthracnose (2,3). To our knowledge, this is the first report of C. higginsianum causing anthracnose of ramie in China and in the world.

Entomosporium mespili에 의한 비파나무 점무늬병 발생

2008년부터 매년 전라남도 고흥군에 위치한 비파나무 묘포장에서 잎에 점무늬 증상이 관찰되었다. 전체 묘목의 50% 이상에서 이러한 증상이 나타났으며, 결국 잎이 일찍 떨어지고 수세가 약화되는 피해가 나타났다. 병반으로부터 관찰된 균은 Entomosporium mespili로 동정되었다. 이 균은 단포자 분리되어 KACC 44727 균주로 보존되었다. 인공접종 실험을 통하여 병원성을 검정하여 코흐의 원칙과 일치하였다. 따라서 국내에 비파나무 점무늬병을 처음으로 보고한다. Since 2008, a new leaf spot disease has been found in loquat tree (Eriobotrya japonica) at a nursery station in Goheung, Korea. Above 50% of the seedlings developed the spot symptoms on the leaves. The infected plants were generally reduced in the seedling vigour and early defoliation was occurred. The infected leaves developed grayish lesion with dark reddish brown margin. The pathogen developed round to ellipsoidal acervuli on the lesion. Based on morphological characteristics of the pathogen, the fungus was identified as Entomosporium mespili. The cultured pathogen successfully reproduced the same disease symptom on the leaves of loquat tree and found to be E. mespili. A monoconidial culture was deposited in Korean Agricultural Culture Collection (KACC 44727). This is the first report of E. mespili causing leaf spot of loquat tree in Korea.

Yellow Dryad, a New Host Plant of Colletotrichum acutatum in Switzerland.

In spring 2008, yellow dryad (Dryas drummondii L.), an ornamental plant, was studied at the Research Center Conthey (Switzerland) for its possible use by the cosmetical industry. Plants grown from wild-type seeds were multiplied by transplanting cuttings in pots that were later transplanted in an experimental field plot. Before field planting, partial wilting occurred on several plants. The petioles of affected leaves appeared dry, tan, and covered with black acervuli containing black setae. Isolation from the acervuli on potato dextrose agar (PDA) containing chlortetracycline (25 mg/liter) resulted in the growth of white-to-gray mycelium containing salmon-colored conidial masses but no setae. The underside of the colony was carmine red. Conidia were primarily fusiform with an average size of 13 × 4 μm. On the basis of these morphological traits, the pathogen was identified as Colletotrichum acutatum J.H. Simmonds (2). PCR using the species-specific primer CaInt2 in conjunction with the conserved primer ITS4 (3) was conducted on genomic DNA from a single-spore isolate. An isolate of C. acutatum from strawberry was included as a positive control. This primer pair produced a 490-bp fragment that confirmed the identification based on morphology. A pathogenicity test was conducted at the end of August and beginning of September 2009. The single-spore isolate from yellow dryad and a single-spore isolate of C. acutatum from highbush blueberry (Vaccinium corymbosum located at Dürrenroth, Switzerland) were grown on PDA at 23 ± 2°C for 1 week. Conidial suspensions were prepared with 0.9% sterile NaCl solution and were adjusted to 3 to 5 × 105 spores/ml. For each spore suspension, five 3- to 5-cm tall, healthy, yellow dryad plants in the rosette stage were sprayed until runoff. Spraying five plants with a sterile 0.9% NaCl solution served as control treatment. Immediately after inoculation, plants were covered individually with a polyethylene bag and incubated at 23 ± 2°C for 5 days. Polyethylene bags were then removed and the plants were placed outdoors under a plastic shelter (18 ± 4°C). After 1 week, plants inoculated with either strain of C. acutatum showed the same symptoms. The most prevalent symptoms on leaves were brown necroses surrounded by a dark brown margin; the necrotic lesions were covered with black acervuli without setae. Less frequent were small, brown lesions that turned gray and were covered with acervuli containing setae. Acervuli with setae also occurred frequently on the petioles of the inoculated plants. On the control plants, none of these symptoms were observed. Leaves with lesions were incubated in a humid chamber for 1 day, resulting in abundant salmon-colored sporulation from the acervuli. C. acutatum was reisolated from such spore masses on PDA. To our knowledge, this is the first report of C. acutatum on yellow dryad. Since C. acutatum is a widespread pathogen worldwide (1), it represents a potential threat to yellow dryad crops grown for ornamental and potentially cosmetical use.

First Report of Black Spot Caused by Colletotrichum gloeosporioides on Paper Mulberry in China.

Paper mulberry, Broussonetia papyrifera (L.) Venten. (family Moraceae), is a fast-growing tree with luxuriant branches and leaves. Because of strong adaptability and tolerance to unfavorable environmental conditions, it is an important tree species for shade or shelter and reforestation in mined areas and on hillsides. During the summer of 2010, brown-to-black spots were observed on leaves of paper mulberry in Baiwangshan Forest Park in Beijing, China. Early symptoms were round or elliptic, light brown, small lesions that later extended to round or irregular spots (4 to 6 × 4 to 8 mm) that were dark brown or black in the center with brown or light brown margins. Several dozen spots were found on severely infected leaves. Leaf tissues (2 × 2 mm), cut from the margins of lesions, were surface disinfected in 0.5% NaOCl solution for 3 min, rinsed three times with sterile water, plated on potato dextrose agar (PDA) and incubated at 25°C with a 12-h light and 12-h dark period. Numerous waxy subepidermal acervuli with setae were observed after 3 days. Acervuli were brown or black, round or elongate, and 100 to 250 μm in diameter. Setae were dark brown, erect straight or slightly curved, and 60 to 74 × 4 to 8 μm with one to two septa. Conidiophores were hyaline or light brown, short with no branches, and cylindrical with dimensions of 12 to 21 × 4 to 5 μm. Conidia were 11 to 21 × 3 to 6 μm, hyaline, aseptate, and cylindrical. Mycelia on PDA were off white-to-dark gray on the reverse side of the colony. Six isolates (BP21-1 to BP21-6) were obtained from different infected leaves and identified as Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. (teleomorph Glomerella cingulata (Stonem.) Spaulding & Schrenk) on the basis of reverse colony color, dimensions and colors of acervuli, conidiophores, and conidia (3). ITS1-5.8S-ITS2 rDNA sequence analysis was performed on all six isolates. The resultant sequences were identical (GenBank Accession No. HQ 654780) and revealed 99% similarity (100% coverage) with C. gloeosporioides isolates in the GenBank (Accession Nos. EU371022.1 and AY376532.1) (2). Pathogenicity was demonstrated using six potted 3-month-old paper mulberry trees. Isolate BP21-2 was grown on PDA for 14 days and conidia were harvested to prepare a suspension of 106 conidia/ml. Three plants were sprayed with the conidial suspension and three were sprayed with sterile water. All trees were covered with plastic bags for 24 h to maintain high humidity and incubated at 25°C for 6 days. All conidia-inoculated trees showed identical symptoms as the infected leaves in the park, while the control trees remained symptom free. Reisolation of the fungus confirmed that the causal agent was C. gloeosporioides. C. gloeosporioides is distributed worldwide causing anthracnose on a wide variety of plants including members of mulberry family Moraceae, e.g., mortality of stem cuttings and death of saplings on mulberry (Morus alba L.) in India (1). To our knowledge, this is the first report of C. gloeosporioides causing black spots on paper mulberry in China.

First Report of Leaf Spot Disease on Dictamnus dasycarpus Caused by Phoma dictamnicola in China.

Fraxinella, Dictamnus dasycarpus Turcz (Rutaceae), is a perennial herbal plant and mainly distributed in Eurasia and North America. It is often used to treat jaundice, cough, rheumatism, and other diseases and is extensively cultivated in the northeast and northwest of China (3). In June 2009, a severe foliar disease was observed on D. dasycarpus in medicinal plantations in Antu, China. The disease occurred on 100% of the plants and at least 25% of the surface was affected. In the early stages of disease development, symptoms were visible on the top and bottom of infected leaves as small brown spots. Subsequently, these spots became elliptical to irregularly shaped, with beige or grayish white centers and dark brown margins. Within the spots, numerous, dark brown or black, subglobose or ostiolate pycnidia measuring 152 to 367 μm in diameter were observed. Fungal isolates were obtained from the infected leaves on potato dextrose agar (PDA) medium, with conidia that were aseptate or one-septate and ellipsoidal or reniform, measuring approximately 4.7 to 12.6 × 2.1 to 4.5 μm. On the basis of these characteristics, the fungus was identified as a Phoma sp. Four well-sporulating isolates, designated as DdPh-1, DdPh-2, DdPh-3, and DdPh-4, were selected for further studies. The morphological and cultural characteristics of these four isolates were studied as described by Boerema et al. and the fungus was identified as Phoma dictamnicola Boerema et al. (1). The internal transcribed spacer (ITS) region of the nuclear rDNA was amplified and sequenced using primers ITS4/ITS5 (2). All four of the ITS sequences were identical (GenBank Accession No. FR681861) and were 99% identical to P. dictamnicola strains CBS507.91 (Accession No. GU237877) and KACC42445 (Accession No. EF600960). Pathogenicity tests were performed by spraying the leaves of healthy D. dasycarpus plants with a conidial suspension (1 × 106 conidia/ml). Five plants were inoculated with each isolate (DdPh-1, DdPh-2, DdPh-3, and DdPh-4) and five plants were mock inoculated with sterile water. The plants were covered with plastic bags and kept in a greenhouse at 20 to 25° for 72 h. After 9 to 13 days, all inoculated plants showed characteristic symptoms as previously described, while the control plants remained healthy. The fungus was reisolated from the leaf spots of inoculated plants. Currently, the economic importance of this disease is limited, but it may become a more significant problem in production of D. dasycarpus with the cultivation area increasing. The fungus was found in the Netherlands and Korea, but to our knowledge, this is the first report of P. dictamnicola on D. dasycarpus in China.

First Report of Passalora Leaf Spot Caused by Passalora bougainvilleae on Bougainvillea in Mexico.

Bougainvillea (Bougainvillea spectabilis Willd) growing in 28 gardens during 2009 showed 100% disease incidence and 3 to 7% disease severity. Bougainvilleas with white flowers were the most affected. Symptoms consisted of light brown spots with dark brown margins visible on adaxial and abaxial sides of the leaves. Spots were circular, 2 to 7 mm in diameter, often surrounded by a chlorotic halo, and delimited by major leaf veins. Single-spore cultures were incubated at 24°C under near UV light for 7 days to obtain conidia. Pathogenicity was confirmed by spraying a conidial suspension (1 × 104 spores/ml) on leaves of potted bougainvillea plants (white, red, yellow, and purple flowers), incubating the plants in a dew chamber for 48 h and maintaining them in a greenhouse (20 to 24°C). Identical symptoms to those observed at the residential gardens appeared on inoculated plants after 45 to 60 days. The fungus was reisolated from inoculated plants that showed typical symptoms. No symptoms developed on control plants treated with sterile distilled water. The fungus produced distinct stromata that were dark brown, spherical to irregular, and 20 to 24 μm in diameter. Conidiophores were simple, born from the stromata, loose to dense fascicles, brown, straight to curved, not branched, zero to two septate, 14 × 2 μm, with two to four conspicuous and darkened scars. The conidia formed singly, were brown, broad, ellipsoid, obclavate, straight to curved with three to four septa, 40 × 4 μm, and finely verrucous with thick hilum at the end. Fungal DNA from the single-spore cultures was obtained using a commercial DNA Extraction Kit (Qiagen, Valencia, CA); ribosomal DNA was amplified with ITS5 and ITS4 primers and sequenced. The sequence was deposited at the National Center for Biotechnology Information Database (GenBank Accession Nos. HQ231216 and HQ231217). The symptoms (4), morphological characteristics (1,2,4), and pathogenicity test confirm the identity of the fungus as Passalora bougainvilleae (Muntañola) Castañeda & Braun (= Cercosporidium bougainvilleae Muntañola). This pathogen has been reported from Argentina, Brazil, Brunei, China, Cuba, El Salvador, India, Indonesia, Jamaica, Japan, Thailand, the United States, and Venezuela (3). To our knowledge, this is the first report of this disease on B. spectabilis Willd in Mexico. P. bougainvilleae may become an important disease of bougainvillea plants in tropical and subtropical areas of Mexico.