First Report of Bacterial Leaf Spot Disease of Broussonetia papyrifera Caused by Pseudomonas syringae pv. actinidiae in China

Broussonetia papyrifera (paper mulberry) is a deciduous tree with a number of uses and is native to northeastern Asia. Because of its fast-growing nature and high tolerance to dust, smoke, and high temperatures, paper mulberry is regarded as an important and economically-valuable component of a biologically diverse community and is used extensively in several areas including medicine, animal husbandry, paper making, weaving, afforestation and light industry (Mei et al. 2016). From June to August of 2019, symptoms on paper mulberry trees were observed in Shiniushan village, Sanhua town, Xishui County, Hubei province of China. Typical symptoms on leaves included small, angular, brown spots surrounded by yellow haloes. These spots coalesced into necrotic areas. The incidence was around 30%, which threatened the survival and reduced the yield of paper mulberry. In order to identify the causal pathogenic organism, leaf samples from 10 different infected trees were collected every two weeks and isolations made over three months. Several circular, flat, granulated colonies with entire margins were isolated on King’s B medium (KB). The biochemical and physiological characteristics of thirty typical strains were tested and listed as following: gram negative, aerobic, rod shaped, and non-fluorescent on King’s B medium; positive for carbohydrate utilization (sucrose, glucose, fructose and arabinose), levan production, hypersensitive on tobacco, potato and tomato; and negative for oxidase, arginine dehydrolase, tyrosinase and urease activity, gelatin liquefaction, and reduction of nitrate. Psa pathovar-specific primers PsaF1/PsaR2 (280bp product ) identified two representative strains as Psa (Rees-George et al. 2010). BLAST analysis further confirmed that the 16S rDNA region amplified by primers 27F/1492R (NCBI accession nos. MT472100 and MT472101) shared 99.84% and 99.77% identity with the Psa type strain ICMP 18884 (CP011972) respectively (Weisburg et al. 1991). For ten typical strains, pathogenicity was confirmed by spraying a bacterial suspension (108 cfu/mL) onto fifty one-year seedlings of B. papyrifera, five seedlings repetitions for each strain. Symptoms of infection similar to those observed initially in the field were detected within 7 days after incubation at 25°C with 80–85% humidity. No symptoms were observed on control plants. The pathogen was re-isolated from symptomatic leaves and re-identified as Psa by morphological characteristics and sequencing. To our knowledge, this is the first report of Psa causing bacterial leaf spot disease on B. papyrifera, China. Psa has been reported as a pathogen causing bacterial canker of kiwifruit worldwide, resulting in severe economic losses to kiwifruit growers (McCann & Li, 2017). As a host of Psa, B. papyrifera may be a source of inoculum for nearby kiwifruit orchards, and consequently effective control measures should be taken to manage this disease. Funding: This study was supported by the National Natural Science Foundation of China (31701974; 31901980), Science and technology program funded by Wuhan Science and Technology Bureau (2018020401011307). References: Mei et al. 2016. Eur J Plant Pathol. 145: 203. McCann & Li et al. 2017. Genome Biol Evol. 9: 932. Rees-George et al. 2010. Plant Pathol. 59: 453 Weisburg et al. 1991. J Bacteriol. 173: 697.

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First Report of Corynespora Leaf Spot on Patchouli Caused by Corynespora cassiicola in China

Plant Disease ◽

10.1094/pdis-07-10-0492 ◽

2010 ◽

Vol 94 (12) ◽

pp. 1508-1508 ◽

Cited By ~ 4

Author(s):

X. Y. Chen ◽

C. Sui ◽

B. C. Gan ◽

J. H. Wei ◽

Y. K. Zhou

Keyword(s):

Leaf Spot ◽

Control Measures ◽

Economic Losses ◽

Leaf Spot Disease ◽

Commonwealth Mycological Institute ◽

Corynespora Cassiicola ◽

Manihot Esculenta Crantz ◽

First Report ◽

Spot Disease ◽

Potted Plants

Patchouli (Pogostemon cablin (Blanco) Benth.) is mainly cultivated in Southeast Asia as a medicinal shrub and a source of patchouli oil used in perfumery. In 2008, a leaf spot disease was observed on patchouli plants grown on most farms (some farms had 99% incidence) in Wanning, the predominant cultivation location in the Hainan Province of China. The disease usually began at the tip of leaves, the main veins, or small veinlets. Severely irregular-shaped dark brown leaf spots expanded over 5 to 10 days, eventually causing infected leaves to abscise. The time from initial leaf lesions to abscission usually took 1 month. The disease was usually most severe in April and May, causing significant economic losses along with quality losses to patchouli oil extracted from leaves. To isolate the causal pathogen, diseased leaves were collected in August 2008 from a farm of the Hainan Branch Institute of Medicinal Plant Development in Wanning, surface sterilized in 75% ethanol for 1 min, transferred to potato dextrose agar (PDA), and incubated at 28°C for 14 days. Single-spore cultures of three isolates were obtained and identified as Corynespora cassiicola (Berk. & Curt.) Wei. on the basis of morphological and physiological features (1). Genomic DNA was extracted from all the cultures. The internal transcribed spacer (ITS) region of the rDNA was amplified using primers ITS1 (5′-TCCGATGGTGAACCTGCGG-3′) and ITS4 (5′-TCCTCCGCTTATTGATATGC-3′). Amplicons were 546 bp (GenBank Accession No. HM145960) and had 99% nucleotide identity with the corresponding sequence (GenBank Accession No. GU138988) of C. cassiicola isolated from cassava (Manihot esculenta Crantz). To satisfy Koch's postulates, 50-day-old potted plants in a tent were sprayed until runoff with a spore suspension (1 × 106 spores/ml) prepared from 10-day-old cultures. Using this spray method, one isolate was inoculated separately onto nine leaves of three potted plants. The potted plants were covered with plastic bags to maintain high humidity for 48 h and then placed outside under natural environmental conditions (temperature 20 to 28°C). Another nine leaves of three potted plants, sprayed only with sterile water, served as noninoculated control plants. Leaf spot symptoms similar to those on diseased field plants appeared after 7 days on all inoculated plants. C. cassiicola was reisolated from all inoculated test plants. No symptoms were observed on the control plants. To our knowledge, this is the first report of C. cassiicola causing a leaf spot disease on patchouli in China. Other previous reports of this disease were from Cuba (2). This pathogen has also been reported previously to be economically important on a number of other hosts. On patchouli plants, more attention should be given to prevention and control measures to help manage this disease. References: (1) M. B. Ellis. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute: Kew, Surrey, England, 1971. (2) I. Sandoval et al. Cienc. Tec. Agric., Prot. Plant. 10:21, 1987.

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First Report of Leaf Spot Disease Caused by Exserohilum rostratum on Pineapple in Hainan Province, China

Plant Disease ◽

10.1094/pdis-11-11-0979 ◽

2012 ◽

Vol 96 (3) ◽

pp. 458-458 ◽

Cited By ~ 4

Author(s):

Z. W. Luo ◽

F. He ◽

H. Y. Fan ◽

X. H. Wang ◽

M. Hua ◽

...

Keyword(s):

Leaf Spot ◽

Leaf Spot Disease ◽

Hainan Province ◽

Conidial Suspension ◽

Potato Dextrose Agar Medium ◽

First Report ◽

Spot Disease ◽

Exserohilum Rostratum ◽

Plant Pathol ◽

Pineapple Leaves

Pineapple (Ananas comosus (L.) Merr.) is an important perennial monocotyledonous plant that serves as an important fruit crop globally and is also produced in the Hainan Province of China where production in 2009 was 296,600 t. In July 2009, atypical symptoms of a leaf spot disease were observed on mature pineapple leaves in Chengmai County; approximately 15% of plants propagated from suckers became symptomatic after 150 to 300 days, eventually causing a 3 to 10% yield loss. In the initial infection stage, grayish white-to-yellowish white spots emerged on the leaf surfaces that ranged from 1.0 to 2.4 × 0.3 to 0.7 cm; black specks were not always present in the spots. Leaf spots also had distinctive light brown-to-reddish brown banding pattern on the edges. Several spots would often merge to form large lesions, 6.5 to 15.4 × 2.5 to 5.6 cm, covering more than 67% of the leaf surface, which can lead to death of the plant. Infected pineapple leaves collected from an orchard of Chengmai County were surface sterilized (75% ethanol for 30 s, 0.1% HgCl2 for 2 min, and rinsed three times in sterile distilled water). Leaf pieces were placed on potato dextrose agar medium and then incubated at 25°C. The emerging fungal colonies were grayish white to brown. Similar strains were obtained from Qionghai City and Wanning City subsequently. Two isolates, ITF0706-1 and ITF0706-2, were used in confirmation of the identity of the pathogen and in pathogenicity tests. Colonies were fast growing (more than 15 mm per day at 25 to 30°C) with dense aerial mycelia. Conidia were fusiform, pyriform to oval or cylindrical, olive brown to dark brown, 3 to 10 septate (typically 5 to 8), 33.2 to 102.5 × 9.0 to 21.3 μm, with a strongly protruding hilum bulged from the basal cell, which were similar to the Type A conidia described by Lin et al. (3). The strains were subjected to PCR amplification of the internal transcribed spacer (ITS)1-5.8S-ITS2 regions with universal primer pair ITS1/ITS4. The ITS sequence comparisons (GenBank Accession Nos. JN711431 and JN711432) shared between 99.60 and 99.83% identity with the isolate CATAS-ER01 (GenBank Accession No. GQ169762). According to morphological and molecular analysis, the two strains were identified as Exserohilum rostratum (Drechs.) Leonard & Suggs. Pathogenicity experiments were conducted five times and carried out by spraying a conidial suspension (105 CFU/ml) on newly matured leaves of healthy pineapple plants; plants sprayed with sterile water served as the negative control. Plants were incubated in the growth chamber at 20 to 25°C. Symptoms of leaf spot developed on test plants 7 days after inoculation while the control plants remained asymptomatic. Koch's postulates were fulfilled with the reisolation of the two fungal strains. Currently, E. rostratum is one of the most common pathogens on Bromeliads in Florida (2) and has been reported on Zea mays (4), Musa paradisiacal (3), and Calathea picturata (1) in China, but to our knowledge, this is the first report of leaf spot disease caused by E. rostratum on pineapple in Hainan Province of P.R. China. References: (1) L. L. Chern et al. Plant Dis. 95:1033, 2011. (2) R. M. Leahy. Plant Pathol. Circ. No. 393. Florida Department of Agriculture and Consumer Services Division of Plant Industry, 1999. (3) S. H. Lin et al. Australas. Plant Pathol. 40:246, 2011. (4) J. N. Tsai et al. Plant Pathol. Bull. 10:181, 2001.

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First Report of Nigrospora oryzae Causing Leaf Spot on Ginger in China

Plant Disease ◽

10.1094/pdis-02-21-0260-pdn ◽

2021 ◽

Author(s):

Zeng-Liang LIU ◽

Shuangyun Zhou ◽

Liangliang Qi ◽

Xiaoguo Wang ◽

Juan Song ◽

...

Keyword(s):

Leaf Spot ◽

Disease Incidence ◽

Morphological Characteristics ◽

Control Measures ◽

Likelihood Method ◽

Effective Control ◽

Economic Losses ◽

Leaf Spot Disease ◽

First Report ◽

Nigrospora Oryzae

Ginger (Zingiber officinale Rosc.) is an herbal crop widely grown in China for its medicinal and savory qualities of rhizomes. In August 2018, leaf spot symptoms were observed on ginger plants grown in a field in Nanning, Guangxi Province (E108°3'54", N23°14'48"). Disease incidence was above 50%, and in a Nanning field, rhizome yield loss was almost 30%. Early symptoms appeared as circular, necrotic areas that later developed into circular or irregular spots. The centers of the lesions were white and often surrounded by chlorotic halos (Figure S1A). In severe infections, the spots frequently coalesced, causing the entire leaf to become withered and curved. Small pieces (3 to 4 mm2) from the margin of infected lesions were surface sterilized in 75% ethanol for 40 s followed by 1% NaOCl for 90 s, placed on potato dextrose agar (PDA) and incubated at 28°C in the dark for 4 days. Hyphal tips from the leading edge of colonies were transferred to fresh PDA plates to obtain pure cultures. Fungal colonies were initially white, then turned black/grayish brown when maintained in the dark at 28°C after 5 days (Figure S1B). Conidia were single-celled, brown, or black, smooth, spherical, or subspherical with diameters varying from 9.5 to 15 μm (mean = 13.5 ± 0.72 µm, n = 50) (Figure S1C). Based on these morphological characteristics, the isolates were provisionally identified as Nigrospora oryzae (Ellis 1971; Hudson 1963). Genomic DNA was extracted from a representative isolate Sjb-2. The internal transcribed spacer (ITS) region, beta-tubulin (TUB2), and the translation elongation factor 1-alpha (TEF1-α) were amplified using primer pairs including ITS1/ITS4 (White et al. 1990), Bt-2a/Bt-2b (Glass and Donaldson 1995), and EF1-728F/EF1-986R (Carbone et al. 1999), respectively. The obtained ITS sequence (GenBank accession no. MW555242), TUB2 sequence (MZ048644), and TEF1-α sequence (MZ048645) showed >99% similarity with several GenBank sequences of N. oryzae (KF516962 for ITS; MK550707 for TUB2; and KY019425 for TEF1-α, respectively). Based on the combined sequences of ITS, TUB2 and TEF1-α sequences, a phylogenetic tree was constructed using the maximum likelihood method and confirmed that the isolates were N. oryzae (Figure S2). Pathogenicity of the isolate was confirmed by fulfilling Koch’s postulates. Agar blocks (3 mm diameter) containing a fungal mycelium were placed on detached healthy leaves of ginger. The leaves were then wrapped with sterile polyethylene and incubated in a greenhouse at 25°C with 60% RH. Within 7 days, symptoms appeared on inoculated leaves similar to spots observed in the field, whereas controls remained symptomless. The same pathogen was reisolated from the spots. Pathogenicity tests were performed twice with three replications, indicating that N. oryzae is responsible for leaf spot disease on ginger. The disease in ginger caused by N. oryzae had been reported in Southern Africa (Grech et al. 1989). To our knowledge, this is the first report of N. oryzae causing leaf spot of ginger in China. In the field, this pathogen can substantially affect ginger's health and rhizome yield if no effective control measures are implemented. Therefore, management of the disease should be further investigated to avoid major economic losses.

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TWO NEW SEVERE LEAF SPOT DISEASE ON FOREST TREES OF JALGAON (MAHARASTRA) INDIA

FLORA AND FAUNA ◽

10.33451/florafauna.v23i2pp288-290 ◽

2017 ◽

Vol 23 (2) ◽

Author(s):

S. A. FIRDOUSI

Keyword(s):

Leaf Spot ◽

Fungal Disease ◽

Leaf Spot Disease ◽

Forest Trees ◽

First Report ◽

Spot Disease ◽

Severe Leaf

During the survey of the forest fungal disease, of Jalgaon district, two severe leaf spot diseases on Lannae coromandelica and ( Ougenia dalbergioides (Papilionaceae) were observed in Jalgaon, forest during July to September 2016-17. The casual organism was identified as Stigmina lanneae and Phomopsis sp. respectively1-4,7. These are first report from Jalgaon and Maharashtra state.

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A rapid leaf-disc vacuum-infiltration screening for assessing resistance to bacterial leaf spot disease in anthurium

Scientia Horticulturae ◽

10.1016/j.scienta.2021.110344 ◽

2021 ◽

Vol 288 ◽

pp. 110344

Author(s):

Annelle W.B. Holder-John ◽

Winston Elibox ◽

Pathmanathan Umaharan

Keyword(s):

Leaf Spot ◽

Leaf Disc ◽

Vacuum Infiltration ◽

Leaf Spot Disease ◽

Bacterial Leaf Spot ◽

Spot Disease

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First report of chick peach (Prunus persica L.) leaf spot disease caused by Didymella glomerata in China

Journal of Plant Pathology ◽

10.1007/s42161-021-00834-0 ◽

2021 ◽

Author(s):

Yiping Cui ◽

Aitian Peng ◽

Xiaobing Song ◽

Baoping Cheng ◽

Jinfeng Ling ◽

...

Keyword(s):

Leaf Spot ◽

Prunus Persica ◽

Leaf Spot Disease ◽

First Report ◽

Spot Disease

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First report of banana (Musa acuminate L. AAA Cavendish, cv. Formosana) leaf spot disease caused by Curvularia geniculata in China

Plant Disease ◽

10.1094/pdis-09-21-2001-pdn ◽

2021 ◽

Author(s):

Yanxiang Qi ◽

Yanping Fu ◽

Jun Peng ◽

Fanyun Zeng ◽

Yanwei Wang ◽

...

Keyword(s):

Leaf Spot ◽

Disease Incidence ◽

Morphological Characteristics ◽

Universal Primers ◽

Leaf Spot Disease ◽

Leaf Margin ◽

Conidial Suspension ◽

Tropical Fruit ◽

First Report ◽

Spot Disease

Banana (Musa acuminate L.) is an important tropical fruit in China. During 2019-2020, a new leaf spot disease was observed on banana (M. acuminate L. AAA Cavendish, cv. Formosana) at two orchards of Chengmai county (19°48ʹ41.79″ N, 109°58ʹ44.95″ E), Hainan province, China. In total, the disease incidence was about 5% of banana trees (6 000 trees). The leaf spots occurred sporadically and were mostly confined to the leaf margin, and the percentage of the leaf area covered by lesions was less than 1%. Symptoms on the leaves were initially reddish brown spots that gradually expanded to ovoid-shaped lesions and eventually become necrotic, dry, and gray with a yellow halo. The conidia obtained from leaf lesions were brown, erect or curved, fusiform or elliptical, 3 to 4 septa with dimensions of 13.75 to 31.39 µm × 5.91 to 13.35 µm (avg. 22.39 × 8.83 µm). The cells of both ends were small and hyaline while the middle cells were larger and darker (Zhang et al. 2010). Morphological characteristics of the conidia matched the description of Curvularia geniculata (Tracy & Earle) Boedijn. To acquire the pathogen, tissue pieces (15 mm2) of symptomatic leaves were surface disinfected in 70% ethanol (10 s) and 0.8% NaClO (2 min), rinsed in sterile water three times, and transferred to potato dextrose agar (PDA) for three days at 28°C. Grayish green fungal colonies appeared, and then turned fluffy with grey and white aerial mycelium with age. Two representative isolates (CATAS-CG01 and CATAS-CG92) of single-spore cultures were selected for molecular identification. Genomic DNA was extracted from the two isolates, the internal transcribed spacer (ITS), large subunit ribosomal DNA (LSU rDNA), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), translation elongation factor 1-alpha (TEF1-α) and RNA polymerase II second largest subunit (RPB2) were amplified and sequenced with universal primers ITS1/ITS4, LROR/LR5, GPD1/GPD2, EF1-983F/EF1-2218R and 5F2/7cR, respectively (Huang et al. 2017; Raza et al. 2019). The sequences were deposited in GenBank (MW186196, MW186197, OK091651, OK721009 and OK491081 for CATAS-CG01; MZ734453, MZ734465, OK091652, OK721100 and OK642748 for CATAS-CG92, respectively). For phylogenetic analysis, MEGA7.0 (Kumar et al. 2016) was used to construct a Maximum Likelihood (ML) tree with 1 000 bootstrap replicates, based on a concatenation alignment of five gene sequences of the two isolates in this study as well as sequences of other Curvularia species obtained from GenBank. The cluster analysis revealed that isolates CATAS-CG01 and CATAS-CG92 were C. geniculata. Pathogenicity assays were conducted on 7-leaf-old banana seedlings. Two leaves from potted plants were stab inoculated by puncturing into 1-mm using a sterilized needle and placing 10 μl conidial suspension (2×106 conidia/ml) on the surface of wounded leaves and equal number of leaves were inoculated with sterile distilled water serving as control (three replicates). Inoculated plants were grown in the greenhouse (12 h/12 h light/dark, 28°C, 90% relative humidity). Necrotic lesions on inoculated leaves appeared seven days after inoculation, whereas control leaves remained healthy. The fungus was recovered from inoculated leaves, and its taxonomy was confirmed morphologically and molecularly, fulfilling Koch’s postulates. C. geniculata has been reported to cause leaf spot on banana in Jamaica (Meredith, 1963). To our knowledge, this is the first report of C. geniculata on banana in China.

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First Report of a Leaf Spot on Snow Lotus Caused by Alternaria carthami in China

Plant Disease ◽

10.1094/pdis-92-2-0318b ◽

2008 ◽

Vol 92 (2) ◽

pp. 318-318

Author(s):

S. Zhao ◽

G. Xie ◽

H. Zhao ◽

H. Li ◽

C. Li

Keyword(s):

Leaf Spot ◽

Disease Incidence ◽

Leaf Spot Disease ◽

Tianshan Mountain ◽

Causal Organism ◽

Saussurea Involucrata ◽

First Report ◽

Spot Disease ◽

Initial Symptoms ◽

Snow Lotus

Snow lotus (Saussurea involucrata Karel. & Kir. ex Sch. Bip.) is an economically important medicinal herb increasingly grown in China in recent years. In June of 2005, a leaf spot disease on commercially grown plants was found in the QiTai Region, south of the Tianshan Mountain area of Xinjiang, China at 2,100 m above sea level. Disease incidence was approximately 60 to 70% of the plants during the 2006 and 2007 growing seasons. Initial symptoms appeared on older leaves as irregularly shaped, minute, dark brown-to-black spots, with yellow borders on the edge of the leaflet blade by July. As the disease progressed, the lesions expanded, causing the leaflets to turn brown, shrivel, and die. A fungus was consistently isolated from the margins of these lesions on potato dextrose agar. Fifty-eight isolates were obtained that produced abundant conidia in the dark. Conidia were usually solitary, rarely in chains of two, ellipsoid to obclavate, with 6 to 11 transverse and one longitudinal or oblique septum. Conidia measured 60 to 80 × 20 to 30 μm, including a filamentous beak (13 to 47 × 3.5 to 6 μm). According to the morphology, and when compared with the standard reference strains, the causal organism of leaf spot of snow lotus was identified as Alternaria carthami (1,4). Pathogenicity of the strains was tested on snow lotus seedlings at the six-leaf stage. The lower leaves of 20 plants were sprayed until runoff with conidial suspensions of 1 × 104 spores mL–1, and five plants sprayed with sterile distilled water served as controls. All plants were covered with a polyethylene bag, incubated at 25°C for 2 days, and subsequently transferred to a growth chamber at 25°C with a 16-h photoperiod. Light brown lesions developed within 10 days on leaflet margins in all inoculated plants. The pathogen was reisolated from inoculated leaves, and isolates were deposited at the Key Oasis Eco-agriculture Laboratory of Xinjiang Production and Construction Group, Xinjiang and the Institute of Biotechnology, Zhejiang University. No reports of a spot disease caused by A. carthami on snow lotus leaves have been found, although this pathogen has been reported on safflower in western Canada (3), Australia (2), India (1), and China (4). To our knowledge, this is the first report of a leaf spot caused by A. carthami on snow lotus in China. References: (1) S. Chowdhury. J. Indian Bot. Soc. 23:59, 1944. (2) J. A. G. Irwin. Aust. J. Exp. Agric. Anim. Husb. 16:921, 1976. (3) G. A. Petrie. Can. Plant Dis. Surv. 54:155, 1974. (4) T. Y. Zhang. J. Yunnan Agric. Univ.17:320, 2002.

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First Report of a Leaf Spot Disease of Bells-of-Ireland (Moluccella laevis) Caused by Cercospora apii in California

Plant Disease ◽

10.1094/pdis.2003.87.2.203a ◽

2003 ◽

Vol 87 (2) ◽

pp. 203-203

Author(s):

S. T. Koike ◽

S. A. Tjosvold ◽

J. Z. Groenewald ◽

P. W. Crous

Keyword(s):

Leaf Spot ◽

Sequence Data ◽

Disease Incidence ◽

Leaf Spot Disease ◽

Conidial Suspension ◽

Internal Transcribed Spacer Region ◽

First Report ◽

Spot Disease ◽

Leaf Spots ◽

Initial Symptoms

Bells-of-Ireland (Moluccella laevis) (Lamiaceae) is an annual plant that is field planted in coastal California (Santa Cruz County) for commercial cutflower production. In 2001, a new leaf spot disease was found in these commercially grown cutflowers. The disease was most serious in the winter-grown crops in 2001 and 2002, with a few plantings having as much as 100% disease incidence. All other plantings that were surveyed during this time had at least 50% disease. Initial symptoms consisted of gray-green leaf spots. Spots were generally oval in shape, often delimited by the major leaf veins, and later turned tan. Lesions were apparent on both adaxial and abaxial sides of the leaves. A cercosporoid fungus having fasciculate conidiophores, which formed primarily on the abaxial leaf surface, was consistently associated with the spots. Based on morphology and its host, this fungus was initially considered to be Cercospora molucellae Bremer & Petr., which was previously reported on leaves of M. laevis in Turkey (1). However, sequence data obtained from the internal transcribed spacer region (ITS1, ITS2) and the 5.8S gene (STE-U 5110, 5111; GenBank Accession Nos. AY156918 and AY156919) indicated there were no base pair differences between the bells-of-Ireland isolates from California, our own reference isolates of C. apii, as well as GenBank sequences deposited as C. apii. Based on these data, the fungus was subsequently identified as C. apii sensu lato. Pathogenicity was confirmed by spraying a conidial suspension (1.0 × 105 conidia/ml) on leaves of potted bells-of-Ireland plants, incubating the plants in a dew chamber for 24 h, and maintaining them in a greenhouse (23 to 25°C). After 2 weeks, all inoculated plants developed leaf spots that were identical to those observed in the field. C. apii was again associated with all leaf spots. Control plants, which were treated with water, did not develop any symptoms. The test was repeated and the results were similar. To our knowledge this is the first report of C. apii as a pathogen of bells-of-Ireland in California. Reference: (1) C. Chupp. A Monograph of the Fungus Genus Cercospora. Cornell University Press, Ithaca, New York, 1954.

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