bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Hop stunt viroid in Apricot in China
Authors: Yang Y. A. , Wang H. Q. , Guo R. , Cheng Z. M. , Li S. F. , Sano T. 
Published: May 2007

Hop stunt viroid (HSVd), a member of the family Pospiviroidae, was first described as the causal agent of hop stunt disease in Japan. It has since been found in a wide range of hosts including herbaceous and woody hosts (e.g., hop, cucumber, grapevine, citrus, plum, peach, pear, apricot, almond, and pomegranate). It was also detected and characterized in apricot where infection appears to be latent (1). The viroid occurs frequently in apricot. In southeastern Spain, the presence of HSVd was found to infect 81% of apricot trees (2). Apricots originated in China and are extensively cultivated, but HSVd infection in this host has not been reported. In September 2005, a single symptomatic apricot tree, ‘Yin Bai’, one of the most popular and widely grown cultivars in China, was discovered at the Institute of Fruit Science in Changping District in Beijing, Peoples Republic of China. Observed symptoms included a number of yellow spots with an irregular border that scattered in an irregular manner over the leaf surface. Total RNA was extracted and used for return-polyacrylamide gel electrophoresis and reverse transcription-polymerase chain reaction (RT-PCR) (4). Results of both assays were positive for HSVd. A 297-bp full-length DNA fragment was amplified by RT-PCR using primers R1 (5′-GCTGGATTCTGAGAAGAGTT-3′) complementary to HSVd residues 87–106 for the RT reaction, followed by R2 (5′-AACCCGGGGCTCCTTTCTCA-3′) complementary to HSVd residues 67–84 and forward primer F3 (5′-AACCCGGGGCAACTCTTCTC-3′) residues 79–96 for PCR. The primers are located in the strictly conserved central region of the conserved HSVd group and contain the unique endonuclease restriction site SmaI. The amplified products were cloned into pGEM-T (Promega, Madison, WI) and selected for further analysis on the basis of the results of restriction digests. Six individual clones were sequenced and three different sequences were obtained. Nucleic acid sequence (GenBank Accession No. DQ362901) obtained from one clone was 99.3% (nucleotide changes T206→C, C233→T) identical to HSVd.apr8 (GenBank Accession No. Y09349) (3). Sequence (GenBank Accession No. DQ362904) obtained from three clones was 99.7% (nucleotide change C233→T) and a third sequence (GenBank Accession No. DQ362905) obtained from two clones was 99.3% (nucleotide changes G107→A, C233→T) identical to HSVd.apr8. Further investigation is necessary to determine whether the symptoms observed are associated with the viroid infection. To our knowledge, this is the first report of HSVd isolated from apricot in China. References: (1) N. Astruc et al. Eur. J. Plant Pathol. 102:837, 1996. (2) M. C. Cañzres et al. Acta Hortic. 472:581, 1998. (3) S. A. Kofalvi et al. J. Gen. Virol. 78:3177, 1997. (4) S. F. Li et al. Ann. Phytopathol. Soc. Jpn. 61:381, 1995.
First Report of Pythium aphanidermatum on Basella rubra in Japan
Authors: Tojo M. , Yonemoto K. , Kawamura A. 
Published: May 2007

Basella rubra L. (Indian spinach, Japanese name Tsurumurasaki) is cultivated worldwide as an ornamental and its aerial parts are consumed as a vegetable and health food. A severe rot of leaves, stems, and roots was found on B. rubra cv. Midori grown in a commercial field at Naruto-City (34°11′N, 134°36(E) in Tokushima Prefecture, Japan from May to September 2004. More than 50% of approximately 2,100 plants in the field were destroyed by the disease. Soft, black lesions appeared initially at the base of the stems in 2- to 5-month-old plants and enlarged gradually upward and downward within 2 days after plant injury caused by heavy rainfall. A fluffy, white mass of mycelium appeared on the surface of lesions under moist conditions. A Pythium species was routinely isolated from rotted stems and roots and identified as Pythium aphanidermatum (Edson) Fitzpatrick on the basis of its morphology on a grass leaf water culture (2). Characteristics of isolate OPU743 (NBRC No. 101556, MAFF No. 239847) included hyphae as much as 10 μm wide, terminal oogonia 17.8 to 28.8 μm in diameter, and monoclinous or diclinous antheridia 8.8 to 10.9 μm wide, either terminal or intercalary, with one or rarely two per oogonium. Oospores were aplerotic, 13.5 to 22.6 μm in diameter. Sporangia were terminal or occasionally intercalary, and either inflated filamentous hyphae or complexes of swollen hyphal branches were present in cultures. Cardinal temperatures for growth on potato carrot agar were 10°C minimum, 37°C optimum, and 40°C maximum with a daily radial growth rate of 32.9 mm at 25°C. Pathogenicity tests were conducted on potted 3-month-old B. rubra (cv. Midori). A wound (1 mm deep and 5 mm long made by a razor) on the surface of the stem of the plant was inoculated with an 8-mm-diameter agar disk of isolate OPU743 (grown at 25°C for 48 h on potato dextrose agar) attached to a stem of the plant using a paraffin film. The inoculated plants were placed in transparent plastic bags and kept in a growth chamber at 24 to 26°C with continuous light (82 to 126 μmol·m-2·s-1). The experiment was done four times with three plants in each experiment. The same number of plants was used for the noninoculated control. Dark brown rot of stems and leaves developed on 66.7% of inoculated plants within 2 days after inoculation. P. aphanidermatum reisolated from diseased tissues was morphologically identical to the original isolate OPU743. Noninoculated control plants showed no symptoms. P. aphanidermatum has been described on B. rubra in Brazil (1), but has not been reported from other regions of the world. To our knowledge, this is the first report of P. aphanidermatum on B. rubra in Japan. References: (1) C. F. Robbs. A Lavoura 74:43, 1972. (2) A. J. Van Der Plaats-Niterink. Stud. Mycol. 21:1, 1981.
First Report of Armillaria tabescens Causing Armillaria Root Rot of Pindo Palm in South Carolina
Authors: Schnabel G. , Bryson P. K. , Williamson M. A. 
Published: May 2007

A Pindo palm tree (Butia capitata) declined in a commercial landscape setting in Georgetown, SC during June of 2005. In the spring, after looking healthy the previous year, the entire canopy collapsed with leaves attached. The canopy defoliated shortly thereafter. A cross section through primary and secondary roots of the wilting plant revealed necrotic areas with the presence of white mycelial fans. Diseased roots containing mycelial fans were collected and small sections were transferred to benomyl dichloran streptomycin (BDS) selective medium. Fungal cultures grew approximately 1 mm in diameter per day and developed aeriel mycelium first. Later, cultures developed mainly crustose mycelium with some parts being aerial. Ribosomal internal transcribed spacer (ITS) regions 1 and 2 were polymerase chain reaction amplified with universal primers ITS1-F and ITS4 and sequenced (GenBank Accession No. DQ109806). A BLAST search in GenBank of the ITS1-5.8S-ITS2 region identified the pathogen as Armillaria tabescens (Scop.) Emel (synonym Clitocybe tabescens (Fr.) Bres) with 98% sequence homology to A. tabescens single-spore isolate ss23 from South Carolina (Accession No. AY695408). The diploid culture from the roots of the Pindo palm was compatible with haploid tester strains of A. tabescens as indicated by diploidization of the haploid mycelium. The disease has been reported on Pindo palm in Florida (1), but to our knowledge, this is the first report of A. tabescens causing disease on Butia species in South Carolina. Our findings indicate that Pindo palm trees could be at risk for infection and should not be cultivated in soils containing pathogenic Armillaria species. Reference: (1) S. A. Alfieri, Jr. et al. Index of Plant Diseases in Florida (Revised). Fla. Dep. Agric. Consum. Serv. Div. Plant Ind. Bull. 11:389, 1984.
Occurrence of Botrytis cinerea on Pelargonium spp. in Argentina
Authors: Palmucci H. E. , Wright E. R. 
Published: May 2007

Pelargonium spp. are perennial ornamental plants used as potted plants or bedding plants in gardens. During the spring and summer of 2003, symptoms of an unknown disease appeared on florists' geranium (Pelargonium inquinans (L.) L'Herit) and ivy geranium (P. peltatum (L.) L'Herit.) adult plants growing in gardens in the suburbs of Buenos Aires. Flowers showed small, water-soaked spots that expanded and eventually blighted the petals. Brown, circular to irregular, water-soaked spots developed in leaves and advanced into the peduncules. A fungus was isolated from diseased leaf tissue on potato dextrose agar after surface disinfestations in 2% NaOCl for 2 min. Pure cultures formed a whitish, dense mycelial mat and turned gray after 72 h. Conidia were ellipsoid, hyaline, nonseptate, and were formed on botryose heads with an average size of 8.6 × 10.2 μm. Black, round, and irregular sclerotia developed on 7-day-old cultures with an average size of 1.1 × 1.7 mm. Morphological characteristics agree with those described for B. cinerea Pers.:Fr (1). Pathogenicity tests were conducted. Five 3-month-old plants of each host were spray inoculated with a conidial suspension (1 × 106 conidia/ml). Three controls of each host were sprayed with sterile distilled water. Plants were covered with plastic bags for 48 h and incubated at 20 ± 2°C with natural light for 15 days. Lesions similar to those observed in natural infection developed after 4 days. B. cinerea was reisolated from lesions, thus completing Koch's postulates. Controls remained symptomless. To our knowledge, this is the first report of B. cinerea causing a disease on Pelargonium. spp. in Argentina. Reference: (1) M. V. Ellis and J. M. Waller. No. 431 in: Descriptions of Pathogenic Fungi and Bacteria. CMI. Kew, Surrey, UK, 1974.
First Report of Cucumber vein yellowing virus on Cucumber, Melon, and Watermelon in Iran
Authors: Bananej K. , Desbiez C. , Girard M. , Wipf-Scheibel C. , Vahdat I. , Kheyr-Pour A. , Ahoonmanesh A. , Lecoq H. 
Published: May 2007

Several viral diseases are responsible for significant economic losses in commercial cucurbit production worldwide. During a survey conducted in July 2002 in cucurbit growing areas in southern Iran, vein-clearing symptoms and leaf chlorosis on older leaves were observed on a cucumber plant near Jiroft (Kerman Province). These symptoms were similar to those caused by Cucumber vein yellowing virus (CVYV, genus Ipomovirus, family Potyviridae), a virus first described in Israel (1) and now widespread in cucurbit crops in the Middle East and Mediterranean Regions (2). The identification of CVYV was established through differential host range reaction and immunosorbent electron microscopy (IEM) experiments. Typical vein-clearing symptoms were observed following mechanical inoculation of cucumber and melon plantlets, but no symptoms were observed in Chenopodium quinoa, C. amaranticolor, Nicotiana tabacum, or Vigna sinensis. Numerous, slightly flexuous, elongated virus particles were observed in infected plant extracts. The particles were decorated by a polyclonal antiserum raised against a Sudanese isolate of CVYV. To confirm CVYV identification, total RNA extracts (TRI-Reagent, Sigma Chemical, St. Louis, MO) were obtained from the original cucumber sample. Reverse transcription-polymerase chain reactions (RT-PCR) were carried out using CVYV-specific primers CVYV-CP-5′: 5′-GCTTCTGGTTCTCAAGTGGA-3′ and CVYV-CP-3′: 5′-GATGCATCAGTTGTCAGATG-3′ designed according to the partial sequence of the coat protein gene of CVYV-Isr (GenBank Accession No. AF233429) (2). A 540-bp fragment corresponding to the central region of CVYV coat protein was obtained from extracts of infected plants but not from healthy plant extracts. Additional watermelon (n = 6) and melon (n = 4) leaf samples collected from plants growing in the same farm were tested for the presence of CVYV using RT-PCR. All samples reacted positively for CVYV. However, a sample of Citrullus colocynthis, a wild relative of watermelon growing nearby, was negative. CVYV was not detected using RT-PCR in 123 additional cucurbit samples collected from the eastern and central regions of Iran during a survey conducted in 2002. To our knowledge, this is the first report of the occurrence of CVYV in Iran. Additional surveys in southern regions where Bemisia tabaci, the vector of CVYV, is abundant are required to better estimate the prevalence of this virus in cucurbit crops in Iran. References: (1) S. Cohen and F. E. Nitzany. Phytopathol. Mediterr. 1:44, 1960 (2) H. Lecoq et al. J. Gen. Virol. 81:2289, 2000.
First Report of Downy Mildew Caused by Peronospora parasitica on Iberis sempervirens in Italy
Authors: Garibaldi A. , Minuto A. , Gullino M. L. 
Published: May 2007

Iberis sempervirens (evergreen candytuft) is a garden species belonging to the Brassicaceae family. During June 2004, a damaging foliar disease was observed in several commercial farms near Albenga (northern Italy) on I. sempervirens plants grown outdoors in containers. More than 30% of the plants were affected. Symptoms appeared on both sides of leaves, buds, flowers, and fruits. Initially, leaves were slightly chlorotic, but within 5 to 7 days a characteristic whitish furry growth developed on the lower and upper leaf surfaces. The efflorescence was particularly evident on the lower surfaces of leaves and consisted of sporangiophores and sporangia. The appearance and severity of the disease increased because of overhead sprinkler irrigation. Microscopic observations revealed dichotomously branched sporangiophores with slender curved tips. Sporangiophores with a length of 115 to 410 μm (average 295 μm) ended with sterigmata bearing single sporangia. Sporangia were ovoid and measured 18 to 28 × 25 to 45 μm (average 22 × 35 μm). The pathogen was identified as Peronospora parasitica on the basis of its morphological characteristics (3). Pathogenicity was confirmed by inoculating leaves of 10 45-day-old healthy plants grown in 14-cm-diameter pots with a sporangial suspension (1 × 103 conidia/ml). Ten noninoculated plants served as controls. Plants were maintained outdoors at 50% light intensity with temperatures ranging between 16 and 25°C (average 18°C) and 85 to 100% relative humidity. The pathogenicity test was carried out twice. After 18 days, typical symptoms of downy mildew developed on the inoculated plants and P. parasitica was observed on the leaves. Noninoculated plants did not show symptoms. To our knowledge, this is the first report of P. parasitica on evergreen candytuft in Italy. P. parasitica was previously reported on I. sempervirens in the United Kingdom (1) and on I. amara in California (2). Voucher specimens are available at the AGROINNOVA Collection, University of Torino, Italy. References: (1) S. Francis and G. Waterhouse. Trans. Br. Mycol. Soc. 91:1, 1988. (2) P. R. Muller et al. Index of Plant Diseases in the United States. USDA Handbook No. 165, 1960. (3) D. M. Spencer. The Downy Mildews. Academic Press, New York, 1981.
First Report of Tobacco ringspot virus in Pumpkin (Cucurbita pepo) in Illinois
Authors: Jossey S. , Babadoost M. 
Published: May 2007

During a survey of commercial pumpkin and squash fields for viruses, conducted in Illinois in 2005, Tobacco ringspot virus (TRSV) was identified for the first time in symptomatic pumpkin samples collected during August and September from Douglas, Kankakee, Piatt, and Tazewell counties in one of three, one of three, one of one, and one of seven samples tested, respectively. In an earlier study from southern Illinois, the only viruses detected in pumpkins were Cucumber mosaic virus, Papaya ringspot virus, Squash mosaic virus, Watermelon mosaic virus, and Zucchini yellow mosaic virus (2). TRSV has been reported in cucurbits from some states in the United States (1). We detected TRSV in symptomatic leaves exhibiting mild mosaic with leaf yellowing using a double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) kit (Agdia, Inc., Elkhart, IN). Samples were considered positive if the absorbance readings at 405 nm exceeded 3× the absorbance of the negative control. The presence of TRSV was confirmed by reverse transcription-polymerase chain reactions (RT-PCR). Total RNA was extracted from the symptomatic plants using TRIzol Reagent and reverse transcribed by M-MLV Reverse Transcriptase (Invitrogen, Carlsbad, CA). PCR was conducted using forward primer 5′-CTTGCGGCCCAAATCT ATAA-3′ and reverse primer 5′-ACTTGTGCCCAGGAGAGCTA-3′, which anneal to the conserved region in the coat protein gene. The reaction produced an amplification product of the expected size (348 bp). Hence, utilizing ELISA and RT-PCR tests, the presence of TRSV in pumpkin was determined, to our knowledge, for the first time in Illinois. References: (1) R. Provvidenti. Tobacco ringspot. Page 42 in: Compendium of Cucurbit Diseases. T. A. Zitter et al., eds. The American Phytopathological Society, St. Paul, MN. 1996. (2) S. A. Walters et al. HortScience 38:65, 2003.
First Report of Arceuthobium hondurense and Sruthanthus deppeanus in Nicaragua
Authors: Mathiasen R. , Sediles A. , Sesnie S. 
Published: May 2007

The Honduran dwarf mistletoe, Arceuthobium hondurense Hawksw. & Wiens (Viscaceae), is one of the rarest dwarf mistletoes known in Central America (1,2). It is only known from four general areas in Honduras, but has also been reported from three locations in southern Mexico (2,3). At one time, A. hondurense was thought to be in danger of extinction (1). During March 2006, we found three new populations of this rare dwarf mistletoe in the Cordillera Dipilto in northern Nicaragua (Department Nueva Segovia). One population was approximately 11 km northeast of San Fernando (13°44′55″N, 86°19′07″W; elevation 1,130 m), the second population was approximately 9 km north of Mozonte (13°44′09″N, 86°24′54″W; elevation 1,415 m), and the third population was approximately 6 km southwest of Depilto (13°42′51″N, 86°32′22″W; elevation 1,340 m). Honduran dwarf mistletoe was parasitizing Pinus tecunumanii Equiluz & J.P. Perry at each of these locations, and at the Mozonte population, it was also infecting P. oocarpa Schiede ex Schlecht. Only a few pines were infected at each of these localities and no pine mortality associated with dwarf mistletoe infection was observed. However, even lightly infected trees had large witches' brooms and some trees were severely broomed. These populations are 50 to 65 km southeast of the nearest population of Honduran dwarf mistletoe in Honduras and they represent the southern most populations of Arceuthobium spp. in the New World (1). The mistletoe, Struthanthus deppeanus (Cham. & Schlecht.) Bl. (Loranthaceae), also parasitizes pines in Central America and southern Mexico (3). We observed this mistletoe parasitizing P. tecunumanii at the San Fernando location described above, on P. oocarpa approximately 7 km north of Mozonte (13°43′57″N, 86°24′49″W; elevation 1,490 m), and on P. oocarpa approximately 3 km southwest of Dipilto (13°43′40″N, 86°31′56″W; elevation 1,170 m). Again, only a few pines were infected at each of these locations, and we did not observe pine mortality associated with infection by S. deppeanus. S. deppeanus does not cause the formation of witches' brooms on infected pines, but the mistletoe plants are often greater than 1 m long so they are easily observed. This mistletoe was most common southwest of Depilto. To our knowledge, this is the first report of A. hondurense and S. deppeanus in Nicaragua. Specimens of A. hondurense and S. deppeanus from Nicaragua have been deposited at the Deaver Herbarium, Northern Arizona University, Flagstaff (Accession Nos. 81561–81567). References: (1) F. Hawksworth and D. Wiens. Dwarf mistletoes: Biology, pathology, and systematics. USDA For. Serv. Agric. Handb. 709, 1996; (2) R. Mathiasen and J. Melgar, Plant Disease 90:685, 2006; (3) R. Mathiasen et al. Madrono 50:115, 2003.
Downy Mildew of Rudbeckia fulgida cv. Goldsturm by Plasmopara halstedii in Virginia
Authors: Hong C. X. 
Published: May 2007

A severe foliage disease was observed on black-eyed Susan (Rudbeckia fulgida cv. Goldsturm) at a commercial nursery in Virginia Beach, VA in early June of 2005 and 2006. In both years, disease symptoms began after plants were transferred from 1-liter (1quart) to 4-liter (1-gallon) containers. Several hundred ‘Goldsturm’ plants were grown at this nursery but none was marketable because of this disease. Typical symptoms were dark, blotchy necrotic areas on the upper leaf surface. Fuzzy, grayish white zoosporangiophores and zoosporangia were commonly produced on the underside of affected leaves. These disease signs also were observed on both sides of new leaves in severely affected plants. Zoosporangiophores were monopodially branched at right angles with acutely tapering termini. Zoosporangia were ovoid to elliptical, hyaline, and measured 19 to 28 × 17 to 21 μm. On the basis of these morphological characters and host specificity, the organism was identified as Plasmopara halstedii (Farl.) Berl. & De Toni in Sacc. Inoculum at 1.4 × 104 zoosporangia/ml was prepared by washing diseased leaves with deionized reverse osmosis water and applied with a hand sprayer onto the foliage of test plants until runoff. Control plants were treated with deionized reverse osmosis water only. Inoculated and control plants were placed in plastic bags to keep moist for 48 h at 20°C. The inoculated plants developed the same symptoms with fresh crops of the zoosporangiophores and zoosporangia of P. halstedii on the underside of leaves, while the control plants remained healthy 14 days after treatment. The source of the primary inoculum is not known. Interestingly, none of 12 other Rudbeckia spp. and cultivars (R. hirta cvs. Autumn Colors, Becky, Cherokee Sunset, Indian Summer, Irish Eye, Prarie Sun, and Sonora, R. laciniata, R. maxima, R. missouriensis, R. occidentalis cv. Green Wizard, and R. speciosa cv. Viette's Little) grown at the same nursery adjacent to those severely diseased ‘Goldsturm’ plants was affected. Although downy mildew was reported on rudbeckias in north Florida previously (1), to my knowledge, this is the first report from Virginia. This pathogen attacks a number of plants in the genera of Centaurea, Coreopsis, Erigeron, Helianthus, and Verbena in addition to Rudbeckia spp. (2). Thus, it could significantly impact the ornamental plant nursery industry. References: (1) H. Dankers et al. Plant Health Progress. Online publication. doi:10.1094/PHP-2004-0119-01-HN, 2004. (2) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989.