First Report of Citrus Blight in Costa Rica

Citrus blight (CB), causing a chronic decline of citrus, has been an important disease in Florida for over 100 years. CB was first reported in Brazil in the 1980s and is now responsible for the removal of nearly 10% of the trees from production annually. No causal agent has been identified, but CB has been root-graft transmitted to healthy trees, suggesting that the causal agent is infectious (3). Since 1997, CB symptoms were observed in several groves in northern Costa Rica, the most important citrus area of approximately 25,000 ha. Symptoms observed include a general decline and wilt of the tree canopy, off-color leaves, leaf drop, twig dieback, small fruit, delayed blossom, poor growth, and death. A survey near Guanacaste revealed CB symptoms in 7-yr-old Valencia and Pineapple orange trees (Citrus sinensis (L.) Osbeck) grafted on Carrizo citrange (C. sinensis (L.) Osbeck × Poncirus trifoliata (L.) Raf.) rootstock. Since 1997, 6% of the trees in this area have been replanted annually because of CB symptoms. Similar situations were observed in other groves in the northern citrus area. Dot immunobinding assays (DIBA) (1) were used to detect the P12 protein associated with CB with 20 of 22 trees showing CB-like symptoms giving a positive test. Zinc (Zn) accumulation in trunk wood and water uptake tests were done according to Roistacher (2) in 8 healthy and 20 symptomatic trees which were positive for CB using DIBA. The average Zn concentration of 16 declining trees was 4.6 ± 1.9, whereas the average concentration for 8 healthy trees was 2.0 ± 0.9. The average water uptake in 1 min was 14 ml for healthy trees, and virtually zero for the 20 symptomatic trees. These diagnostic tests confirm the presence of CB in the northern citrus area of Costa Rica, and the surveys indicate the disease is beginning to spread and become economically important. To our knowledge, this is the first report of CB in commercial citrus in Costa Rica. References: (1) K. S. Derrick et al. Plant Dis. 74:168, 1990. (2) C. N. Roistacher. Pages 57–66 in: Graft-Transmissible Diseases of Citrus. Handbook for Detection and Diagnosis. C.N. Roistacher, ed. Food and Agriculture Organization, Rome, 1991. (3) D. P. H. Tucker et al. Plant Dis. 68:979, 1984.

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First Report of Armillaria Root Rot Caused by Armillaria mellea Infecting Carrizo Citrange and Sour Orange Rootstocks in Turkey

Plant Disease ◽

10.1094/pdis-05-14-0463-pdn ◽

2014 ◽

Vol 98 (10) ◽

pp. 1439-1439 ◽

Cited By ~ 1

Author(s):

F. Baysal-Gurel ◽

A. Cinar

Keyword(s):

Root Rot ◽

Root Systems ◽

Causal Agent ◽

Poncirus Trifoliata ◽

Sour Orange ◽

Potato Dextrose Broth ◽

First Report ◽

Armillaria Mellea ◽

Carrizo Citrange ◽

Armillaria Root Rot

Citrus rootstocks, Carrizo citrange (Citrus sinensis [L.] Osb. × Poncirus trifoliata [L.] Raf.) and sour orange (C. aurantium L.) grown in containers filled with 5 liters of potting mix of 40% peat and 60% volcanic tuff declined in a 0.2-ha commercial nursery in Adana, Turkey, between 2004 and 2007. Seedlings with symptoms of root rot were found with an average disease incidence of 20% among 1,000 Carrizo citrange seedlings and 10% among 15,000 sour orange seedlings. The potting mixture preparation unit was located next to an oak tree (Quercus sp.) showing symptoms of Armillaria root rot. Six- to 12-month-old seedlings of both rootstocks were stunted and the crowns were necrotic with the presence of white mycelium. Mycelial fans were observed beneath the bark of infected roots and they expanded into the crown. The root systems and nearby potting mix contained rhizomorphs. Thus, Armillaria spp. was suspected as a possible causal agent. Three diseased crowns and three rhizomorphs were surface-sterilized with 1% NaClO for 1 min and cultured on benomyl-dichloran-streptomycin containing selective medium (3) at 25°C in the dark for 1 week. Six isolates transferred to 1.5% malt extract agar at 33°C in the dark for 7 weeks consistently yielded abundant aerial hyphae and mean diameter growth range was 4 to 21 mm and the mycelium margin was regular (1). To confirm pathogen identity, total DNA was extracted using the PowerSoil DNA Isolation Kit (MO BIO Laboratories, Inc., CA) directly from 7-day-old cultures grown in potato dextrose broth (PDB). The ribosomal DNA internal transcribed spacer (ITS) region was amplified by PCR using the primer pair ITS1 and ITS4 (5) and sequenced. The sequences were 99% identical to that of Armillaria mellea isolates from Japan (AB510880) and China (KF032535). This confirmed the identity of the causal agent as A. mellea (Vahl.) P. Kumm. Ten 3-month-old seedlings of Carrizo citrange and sour orange were transplanted into steam-sterilized potting mix and inoculated with wood pieces of oak (Quercus sp.) colonized by the fungus (two pieces for each container) (2). The oak wood pieces were sterilized prior to the colonization by the pathogen. Plants were maintained in a greenhouse (23 to 25°C) until symptoms appeared. Ten non-inoculated seedlings from each rootstock served as controls and were maintained in the same environment. After 4 months, the crowns of the seedlings developed necrotic areas and root systems contained rhizomorphs on all inoculated seedlings and fungus was re-isolated from crowns and rhizomorphs. All control plants remained disease-free and no fungus was re-isolated. A. mellea was reported to infect citrus rootstocks in Spain in 1999 (4). To our knowledge, this is the first report of Armillaria root rot caused by A. mellea infecting Carrizo citrange and sour orange rootstocks in Turkey. This indicates that citrus rootstocks could be at risk for infection and sterilization of the potting mix and good sanitation practices in nurseries are very important. References: (1) J. N. Bruhn et al. Mycopathologia 142:89, 1998. (2) F. M. Grasso et al. Plant Dis. 91:1517, 2007. (3) T. C. Harrington et al. Page 81 in: Methods for Research on Soilborne Phytopathogenic Fungi. APS Press, St. Paul, MN, 1992. (4) J. J. Tuset et al. Bol. San. Veg. Plagas 25: 491, 1999. (5) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

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Performance of `Hamlin' Orange on 16 Rootstocks in East-central Florida

HortScience ◽

10.21273/hortsci.30.1.41 ◽

1995 ◽

Vol 30 (1) ◽

pp. 41-43 ◽

Cited By ~ 11

Author(s):

Heinz K. Wutscher ◽

Laura Lee Hill

Keyword(s):

Citrus Sinensis ◽

Poncirus Trifoliata ◽

Trifoliate Orange ◽

Poor Growth ◽

East Central ◽

Central Florida ◽

Citrus Rootstock ◽

Citrus Blight ◽

Freeze Damage ◽

Swingle Citrumelo

`Hamlin' orange (Citrus sinensis L. Osbeck) was grown on 15 rootstocks: four citrumelos [C. paradisi Macf. × Poncirus trifoliata (L.) Raf.], five mandarin × trifoliate orange hybrids (C. reticulata Blanco × P. trifoliata), two pummelo × trifoliate orange hybrids [C. grandis (L.) × P. trifoliata], Vangasay lemon (C. limon Burm. f.), Norton citrange (C. sinensis × P. trifoliata), and two Smooth Flat Seville (C. aurantium L. hybrid?) hybrids. These scion–rootstock combinations were compared to trees on Swingle citrumelo, the most widely used citrus rootstock in Florida. One Smooth Flat Seville hybrid was eliminated early because of poor growth and variability in size, and the Vangasay lemon rootstock was eliminated because of severe freeze damage. At age 5, the trees on Norton citrange developed citrus blight and were eliminated. Remaining in the experiment for 7 years, `Hamlin' trees on six of the 13 rootstocks produced more fruit than trees on Swingle citrumelo. Of these six, HRS 852 (Changsha mandarin × English large-flowered trifoliate orange) was the best overall rootstock, with trees on it producing large quantities of high-quality fruit on medium-sized canopies.

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First report of a subcutaneous infection by Cryptococcus neoformans (former Cryptococcus neoformans var. grubii) in a cat in Costa Rica

Brazilian Journal of Microbiology ◽

10.1007/s42770-021-00555-7 ◽

2021 ◽

Author(s):

Roberto W. I. Olivares ◽

Karla Quesada Mora ◽

Laura G. Bass ◽

Vinicio Carvajal Matamoros ◽

Paula Peña Álvarez ◽

...

Keyword(s):

Costa Rica ◽

Cryptococcus Neoformans ◽

First Report ◽

Subcutaneous Infection

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First Report of Mosaic Disease Caused by Colombian datura virus on Solanum lycopersicum Plants Commercially Cultivated in Japan

Plant Disease ◽

10.1094/pdis-06-13-0668-pdn ◽

2014 ◽

Vol 98 (5) ◽

pp. 698-698 ◽

Cited By ~ 1

Author(s):

Y. Tomitaka ◽

T. Usugi ◽

R. Kozuka ◽

S. Tsuda

Keyword(s):

Nucleotide Sequence ◽

Solanum Lycopersicum ◽

Mosaic Disease ◽

Causal Agent ◽

Cultivated Plants ◽

Rt Pcr ◽

Degenerate Primers ◽

Specific Primers ◽

Tomato Plants ◽

First Report

In 2009, some commercially grown tomato (Solanum lycopersicum) plants in Chiba Prefecture, Japan, exhibited mosaic symptoms. Ten plants from a total of about 72,000 cultivated plants in the greenhouses showed such symptoms. To identify the causal agent, sap from leaves of the diseased plants was inoculated into Chenopodium quinoa and Nicotiana benthamiana plants. Local necrotic lesions appeared on inoculated leaves of C. quinoa, but no systemic infection was observed. Systemic mosaic symptoms were observed on the N. benthamiana plants inoculated. Single local lesion isolation was performed three times using C. quinoa to obtain a reference isolate for further characterization. N. benthamiana was used for propagation of the isolate. Sap from infected leaves of N. benthamiana was mechanically inoculated into three individual S. lycopersicum cv. Momotaro. Symptoms appearing on inoculated tomatoes were indistinguishable from those of diseased tomato plants found initially in the greenhouse. Flexuous, filamentous particles, ~750 nm long, were observed by electron microscopy in the sap of the tomato plants inoculated with the isolate, indicating that the infecting virus may belong to the family Potyviridae. To determine genomic sequence of the virus, RT-PCR was performed. Total RNA was extracted from the tomato leaves experimentally infected with the isolate using an RNeasy Plant Mini kit (QIAGEN, Hilden, Germany). RT-PCR was performed by using a set of universal, degenerate primers for Potyviruses as previously reported (2). Amplicons (~1,500 bp) generated by RT-PCR were extracted from the gels using the QIAquick Gel Extraction kit (QIAGEN) and cloned into pCR-BluntII TOPO (Invitrogen, San Diego, CA). DNA sequences of three individual clones were determined using a combination of plasmid and virus-specific primers, showing that identity among three clones was 99.8%. A consensus nucleotide sequence of the isolate was deposited in GenBank (AB823816). BLASTn analysis of the nucleotide sequence determined showed 99% identity with a partial sequence in the NIb/coat protein (CP) region of Colombian datura virus (CDV) tobacco isolate (JQ801448). Comparison of the amino acid sequence predicted for the CP with previously reported sequences for CDV (AY621656, AJ237923, EU571230, AM113759, AM113754, and AM113761) showed 97 to 100% identity range. Subsequently, CDV infection in both the original and experimentally inoculated plants was confirmed by RT-PCR using CDV-specific primers (CDVv and CDVvc; [1]), and, hence, the causal agent of the tomato disease observed in greenhouse tomatoes was proved to be CDV. The first case of CDV on tomato was reported in Netherlands (3), indicating that CDV was transmitted by aphids from CDV-infected Brugmansia plants cultivated in the same greenhouse. We carefully investigated whether Brugmansia plants naturally grew around the greenhouses, but we could not find them inside or in proximity to the greenhouses. Therefore, sources of CDV inoculum in Japan are still unclear. This is the first report of a mosaic disease caused by CDV on commercially cultivated S. lycopersicum in Japan. References: (1) D. O. Chellemi et al. Plant Dis. 95:755, 2011. (2) J. Chen et al. Arch. Virol. 146:757, 2001. (3) J. Th. J. Verhoeven et al. Eur. J. Plant. Pathol. 102:895, 1996.

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First Report of Phytophthora capsici as Causal Agent of Snap-bean (Phaseolus vulgaris) Pod Decay in Brazil

Plant Disease ◽

10.1094/pdis-11-16-1602-pdn ◽

2017 ◽

Vol 101 (6) ◽

pp. 1059 ◽

Cited By ~ 1

Author(s):

R. Petry ◽

M. E. N. Fonseca ◽

L. S. Boiteux ◽

A. Reis

Keyword(s):

Phaseolus Vulgaris ◽

Phytophthora Capsici ◽

Causal Agent ◽

Snap Bean ◽

First Report

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Yellow Net of Triumffeta Is Caused by a Geminivirus: A First Report

Plant Disease ◽

10.1094/pdis.1998.82.1.127a ◽

1998 ◽

Vol 82 (1) ◽

pp. 127-127 ◽

Cited By ~ 2

Author(s):

Vipin Hallan ◽

Sangeeta Saxena ◽

B. P. Singh

Keyword(s):

Rainy Season ◽

Blot Hybridization ◽

Southern Blot Hybridization ◽

Viral Disease ◽

Hybridization Experiment ◽

Dorsal Side ◽

Causal Agent ◽

Degenerate Primers ◽

First Report ◽

Initial Symptoms

Triumffeta rhomboidiaceae Jacq. (Tiliaceae family) is an annual rainy season weed that is commonly found throughout India. For the last 3 years, during the rainy season, several plants of T. rhomboidiaceae in and around the gardens of the National Botanical Research Institute have been found with vein yellowing symptoms. The initial symptoms were vein clearing but in later stages the veins became yellow and thickened. In severe cases, the chlorosis extends into interveinal areas, resulting in complete yellowing of the leaves. In a few cases, green leafy or thorny enations could be seen on the dorsal side of the leaf. The disease was investigated to identify the causal agent. Vector transmission studies showed that the causal agent is transmitted by the whitefly, Bemisia tabaci, from infected to healthy seedlings of T. rhomdoidiaceae. Since whitefly transmission of the disease is consistent with a geminivirus as the causal agent, the role of such a virus was investigated. DNA isolated from Triumffeta plants (both from the infected plants in the field as well as from those inoculated experimentally in the greenhouse) showing above mentioned symptoms was amplified with two sets of degenerate primers, PAL1v1978/PAR1c496 (set 1) and PAL1v1978/PCRc1 (set 2), that have been shown to be specific for DNA-A of whitefly transmitted geminiviruses (WTGs), in polymerase chain reaction (1). We could amplify DNA-A fragments of approximately 1.2 kb from set 1 and 0.7 kb from set 2, as expected (1). DNA isolated from healthy seedlings gave no amplification of such fragments. Identification of the amplified DNA fragments (from infected samples) to be of geminiviral in nature was confirmed by Southern blot hybridization carried out under high stringency conditions. DNA-A of Indian tomato leaf curl virus (2) was used as a general probe for WTGs for the above hybridization experiment. Therefore, Triumffeta yellow net disease is caused by a geminivirus. A review of literature revealed that there is no record of a viral disease affecting this weed and, therefore, this is the first report of a viral disease affecting this plant. References: (1) M. R. Rojas et al. Plant Dis. 77:340, 1993. (2) K. M. Srivastava et al. J. Virol. Methods 51:297, 1995.

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First Report of Leptosphaeria biglobosa ‘brassicae’ Causing Blackleg on Brassica juncea var. multisecta in China

Plant Disease ◽

10.1094/pdis-10-20-2173-pdn ◽

2021 ◽

Author(s):

Yuexuan Long ◽

Mingxue Shang ◽

Yue Deng ◽

Chuan Yu ◽

Mingde Wu ◽

...

Keyword(s):

Brassica Juncea ◽

Yellow Pigment ◽

Causal Agent ◽

Control Group ◽

Conidial Suspension ◽

First Report ◽

Fungal Isolates ◽

Dna Fragment ◽

Leptosphaeria Biglobosa ◽

Β Tubulin

Brassica juncea var. multisecta, a leafy mustard, is widely grown in China as a vegetable (Fahey 2016). In May 2018, blackleg symptoms, grayish lesions with black pycnidia, were found on stems and leaves of B. juncea var. multisecta during disease surveys in Wuhan, Hubei Province. Disease incidence was approximately 82% of plants in the surveyed fields (~1 ha in total). To determine the causal agent of the disease, twelve diseased petioles were surface-sterilized and then cultured on potato dextrose agar (PDA) at 20˚C for 5 days. Six fungal isolates (50%) were obtained. All showed fluffy white aerial mycelia on the colony surface and produced a yellow pigment in PDA. In addition, pink conidial ooze formed on top of pycnidia after 20 days of cultivation on a V8 juice agar. Pycnidia were black-brown and globose with average size of 145 × 138 μm and ranged between 78 to 240 × 71 to 220 μm, n = 50. The conidia were cylindrical, hyaline, and 5.0 × 2.1 μm (4 to 7.1 × 1.4 to 2.9 μm, n=100). These results indicated that the fungus was Leptosphaeria biglobosa rather than L. maculans, as only the former produces yellow pigment (Williams and Fitt 1999). For molecular confirmation of identify, genomic DNAs were extracted and tested through polymerase chain reaction (PCR) assay using the species-specific primers LbigF, LmacF, and LmacR (Liu et al. 2006), of which DNA samples of L. maculans isolate UK-1 (kindly provided by Dr. Yongju Huang of University of Hertfordshire) and L. biglobosa ‘brassicae’ isolate B2003 (Cai et al. 2014) served as controls. Moreover, the sequences coding for actin, β-tubulin, and the internal transcribed spacer (ITS) region of ribosomal DNA (Vincenot et al. 2008) of isolates HYJ-1, HYJ-2 and HYJ-3 were also cloned and sequenced. All six isolates only produced a 444-bp DNA fragment, the same as isolate B2003, indicating they belonged to L. biglobosa ‘brassicae’, as L. maculans generates a 331-bp DNA fragment. In addition, sequences of ITS (GenBank accession no. MN814012, MN814013, MN814014), actin (MN814292, MN814293, MN814294), and β-tubulin (MN814295, MN814296, MN814297) of isolates HYJ-1, HYJ-2 and HYJ-3 were 100% identical to the ITS (KC880981), actin (AY748949), and β-tubulin (AY748995) of L. biglobosa ‘brassicae’ strains in GenBank, respectively. To determine their pathogenicity, needle-wounded cotyledons (14 days) of B. juncea var. multisecta ‘K618’ were inoculated with a conidial suspension (1 × 107 conidia/ml, 10 μl per site) of two isolates HYJ-1 and HYJ-3, twelve seedlings per isolate (24 cotyledons), while the control group was only treated with sterile water. All seedlings were incubated in a growth chamber (20°C, 100% relative humidity under 12 h of light/12 h of dark) for 10 days. Seedlings inoculated with conidia showed necrotic lesions, whereas control group remained asymptomatic. Two fungal isolates showing the same culture morphology to the original isolates were re-isolated from the necrotic lesions. Therefore, L. biglobosa ‘brassicae’ was confirmed to be the causal agent of blackleg on B. juncea var. multisecta in China. L. biglobosa ‘brassicae’ has been reported on many Brassica crops in China, such as B. napus (Fitt et al. 2006), B. oleracea (Zhou et al. 2019), B. juncea var. multiceps (Zhou et al. 2019), B. juncea var. tumida (Deng et al. 2020). To our knowledge this is the first report of L. biglobosa ‘brassicae’ causing blackleg on B. juncea var. multisecta in China, and its occurrence might be a new threat to leafy mustard production of China.

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First report ofUromyces alstroemeriae, causal agent of Alstroemeria rust in Argentina

Australasian Plant Pathology ◽

10.1071/ap05061 ◽

2005 ◽

Vol 34 (4) ◽

pp. 595 ◽

Cited By ~ 1

Author(s):

C. Rollán ◽

S. Wolcan ◽

L. Ronco

Keyword(s):

Causal Agent ◽

First Report

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First Report of Colletotrichum boninense Causing Anthracnose on Pepper in China

Plant Disease ◽

10.1094/pdis-04-12-0403-pdn ◽

2013 ◽

Vol 97 (1) ◽

pp. 138-138 ◽

Cited By ~ 7

Author(s):

Y. Z. Diao ◽

J. R. Fan ◽

Z. W. Wang ◽

X. L. Liu

Keyword(s):

Internal Transcribed Spacer ◽

Severe Disease ◽

Causal Agent ◽

Its Sequences ◽

Universal Primers ◽

Pathogenicity Test ◽

Conidial Suspension ◽

Single Spore ◽

First Report ◽

Species Specific

Anthracnose, caused by Colletotrichum spp., is a severe disease and results in large losses in pepper (Capsicum frutescens) production in China (4). Colletotrichum boninense is one of the Colletotrichum species in pepper in China. In August 2011, anthracnose symptoms (circular, sunken lesions with orange to black spore masses) were observed on pepper fruits in De-Yang, Sichuan Province, China. Three single-spore isolates (SC-6-1, SC-6-2, SC-6-3) were obtained from the infected fruits. A 5-mm diameter plug was transferred to potato dextrose agar (PDA); the isolates formed colonies with white margins and circular, dull orange centers. The conidia were cylindrical, obtuse at both ends, and 10.5 to 12.6 × 4.1 to 5.0 μm. The colonies grew rapidly at 25 to 28°C, and the average colony diameter was 51 to 52 mm after 5 days on PDA at 25°C. Based upon these characters, the causal agent was identified as C. boninense. To confirm the identity of the isolates, the internal transcribed spacer (ITS) regions were amplified with the ITS1/ITS4 universal primers (1). The internal transcribed spacer (ITS) sequences (Accession No. JQ926743) of the causal fungus shared 99 to 100% homology with ITS sequences of C. boninense in GenBank (Accession Nos. FN566865 and EU822801). The identity of the causal agent as C. boninense was also confirmed by species-specific primers (Col1/ITS4) (2). In a pathogenicity test, five detached ripe pepper fruits were inoculated with 1 μl of a conidial suspension (106 conidia/mL) or five fruits with 1 μl of sterile water were kept as control. After 7 days in a moist chamber at 25°C, typical anthracnose symptoms had developed on the five inoculated fruits but not on control fruits. C. boninense was reisolated from the lesions, and which was confirmed by morphology and molecular methods as before. There have reports of C. boninense infecting many species of plants, including pepper (3). To our knowledge, this is the first report of C. boninense causing anthracnose on pepper in China. References: (1) A. K. Lucia et al. Phytopathology 93:581, 2002. (2) S. A. Pileggi et al. Can. J. Microbiol. 55:1081, 2009. (3) H. J. Tozze et al. Plant Dis. 93:106, 2009. (4) M. L. Zhang. J. Anhui Agri. Sci. 2:21, 2000.

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