bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Anthracnose of Cagaita Caused by Colletotrichum gloeosporioides in Brazil
Authors: Anjos J. R. N. , Charchar M. J. A. 
Published: May 2007

Cagaita (Eugenia dysenterica Mart. Ex DC.), family Myrtaceae, is an important wild perennial fruit crop in Central Brazil (1). Anthracnose symptoms were observed on cagaita leaves in a field in Brasília, Federal District (S 15° 36′ 16″ W 47° 42′ 42″), in August 2000. A fungus was consistently isolated from infected leaves and grown on potato dextrose agar (PDA) and its identification was made by P. F. Cannon of CABI Bioscience as Colletotrichum gloeosporioides (Penzig) Penzig & Sacc. (IMI 384184). Pathogenicity tests were performed on 16 cagaita seedlings by placing mycelial PDA plugs on leaves previously wounded with a sterile needle. Control plants were inoculated with plugs without mycelia. After inoculations, the plants were placed in a dew chamber maintained at 25°C for 72 h and later transferred to the greenhouse. Necrotic leaf spots developed on 100% of the inoculated plants 4 days later. Koch's postulates were fulfilled by consistently reisolating C. gloeosporioides from inoculated plants. Control plants remained symptomless. Inoculations were repeated twice with the same results. To the authors' knowledge, this is the first report of anthracnose caused by C. gloeosporioides of cagaita in Brazil. Reference: (1) S. P. Almeida et al. 1998. Pages 182–186 in: Cerrado: espécies vegetais úteis. Embrapa Cerrados.
First Report of Exserohilum monoceras on Barnyardgrass in Argentina
Authors: Sisterna M. , Bezus R. 
Published: May 2007

Barnyardgrass, Echinochloa crus-galli (L) Beauv., is ranked as the world's third worst weed (2). Punctiform, purplish brown spots were found on leaves and sheaths of 7- to 8-week-old barnyardgrass in a rice crop cultivated in La Plata, Argentina (34° 54′S, 58° 30′W). Individual lesions ranged from 1 to 2 mm diameter. Isolates from the lesions were identified as Exserohilum monoceras (Drechsler) Leonard & Suggs (1) (confirmed by A. Watson, Univ. McGill, Canada). Cultures on potato dextrose agar formed dark green colonies. Conidia were 75 to 135 × 15 to 19 μm, 5- to 7-distoseptate, straight or slightly curved, fusoid, tapering gradually towards the base, pale- to mid-olivaceous brown, with a small protruding plenum-type hilum. Barnyardgrass at the 3-leaf stage was inoculated in a greenhouse with a suspension of 105 conidia per ml of water to confirm the pathogenicity of E. monoceras. Plants were bagged and kept in a humidity chamber for 48 h, at approximately 16°C. After 10 days lesions developed that were similar to those found on infected plants in the field. E. monoceras was reisolated from these lesions. This pathogen is being studied as a biocontrol agent for barnyardgrass in tropical areas (2). References: (1) J. L. Alcorn. Mycotaxon 7:411, 1978. (2) W. Zhang and A. Watson. Can. J. Bot.75:685, 1997.
Occurrence of Potyviruses on Yam (Dioscorea spp.) in Colombia and First Molecular Characterization of Yam mild mosaic virus
Authors: Dallot S. , Guzmán M. , Bousalem M. 
Published: May 2007

A survey to determine the prevalence of potyviruses on yams, Dioscorea alata and D. cayenensis-rotundata, was undertaken in Colombia. Two hundred fifty leaf samples showing mottling symptoms were collected on the Atlantic coast and analyzed by antigen-coated plate enzyme-linked immunosorbent assay with universal potyvirus monoclonal antibodies (Agdia, Elkhart, IN). Potyviruses were detected in 70% (165/235) of the D. alata and in 66% (10/15) of the D. cayenensis-rotundata samples. The presence of Yam mild mosaic virus (YMMV) was indicated in some of these samples by immunocapture reverse-transcriptase polymerase chain reaction performed as previously reported (1). A 600-bp fragment that included the core and C-terminal region of the coat protein gene (CP) and the 3′ untranslated region (3′UTR) was amplified from a D. alata isolate using universal potyvirus primers (1), cloned, and sequenced (EMBL Acc. AJ311725). Comparison with the two previously published YMMV sequences revealed 96.1 and 97.4% identity for the deduced amino acid sequence in the CP region, 74.1 and 83.2% nucleotide identity in the 3′UTR for Papua New Guinea (AB022424 [2]) and Martinique (AJ250336) isolates, respectively. YMMV is known to be widespread on D. alata in Africa and the South Pacific and has been recently identified in the Caribbean (1). To our knowledge, this is the first report of its occurrence in Colombia. A study of its incidence and genetic diversity in South America has been undertaken. References: (1) M. Bousalem and S. Dallot. Plant Disease 84:200, 2000. (2) S. Fuji et al. Arch Virol. 144:1415, 1999.
First Report on the Occurrence of Bacterial Stripe Organism Acidovorax avenae subsp. avenae in Rice Seeds from Burkina Faso
Authors: Somda I. , Veena M. S. , Mortensen C. N. 
Published: May 2007

Breeder rice seeds from Burkina Faso harvesteds in 1999 were tested for Acidovorax avenae subsp. avenae. This pathogen affects rice, maize, sorghum, and other Gramineae. Ten samples of 200 seeds in each sample were tested by the cassette holder method for detection of this bacterium (1). Seedlings were evaluated for symptom development after 14 days at 27 to 30°C and 100% relative humidity under fluorescent light (12 h photoperiod). Bacterial stripe symptoms were observed in seedlings raised from 9 of 10 seed samples tested, and incidence ranged from 5 to 20%. Diseased seedlings showed water-soaked areas on coleoptiles and brown stripes on leaf sheaths and mid-ribs. Twenty-six strains obtained from diseased seedlings were characterized using several criteria. Colonies were small, whitish-grey, raised, entire and translucent on nutrient agar and cream-tan, raised, entire, and did not produce fluorescent pigment on King's medium B. They were Gram negative, oxidase positive and nitrate positive. Variable reactions were recorded for starch hydrolysis; 22 strains reacted positively and 4 negatively. All 26 strains reacted positively in ELISA performed with antiserum against A. avenae subsp. avenae. Results using Biolog GN MicroPlates (Biolog Inc., Hayward, CA computer identification system, Release 4.0) showed all strains to be A. avenae subsp. avenae (sim. 0.709 to 0.802). Hypersensitive reactions on leaves of 2-month-old tobacco plants infiltrated with bacterial suspensions were recorded within 24 h. Strains were tested for pathogenicity by injecting stems of 21-day-old rice plants with bacterial suspensions (approximately 108 CFU/ml). Inoculated seedlings were incubated for 4 to 7 days under humid conditions at 28°C. Inoculated rice plants showed brown stripes and non-inoculated control seedlings remained symptomless. Based on biochemical, serological, and biological characteristics, strains were identified as A. avenae subsp. avenae. This is the first report of A. avenae subsp. avenae, causal agent of bacterial stripe of rice, in Burkina Faso. The common presence of A. avenae subsp. avenae in breeder rice seeds emphasizes the need for control measures to limit further spread to unaffected rice-growing areas and other cereal crops. Reference: (1) D. D. Shakya et al. Phytopathol. Z. 114:256–259, 1985.
First Report of Infection of Hop Cones by Alternaria alternata in Australia
Authors: Pethybridge S. J. , Hay F. S. , Wilson C. R. , Sherriff L. J. , Leggett G. W. 
Published: May 2007

The hop (Humulus lupulus L.) is a dioecious climbing plant, cultivated for its resins, which are produced in the cone, used primarily for the bittering of beer. In Australia, hops are grown in the states of Victoria and Tasmania. In late summer 2001, necrotic lesions were observed on the tips of bracts and bracteoles of developing cones at three hop farms in Tasmania. The necrotic area varied between 1 and 25% of the bracts and bracteoles, and in some cases progressed throughout the entire hop cone. Pieces of infected hop cones were surface sterilized for one minute in 2% sodium hypochlorite, plated on 2% water agar, and incubated at 22 ± 2°C. The most frequently isolated fungi (total number of isolations = 60) were transferred to 2% water agar and potato dextrose agar. In 90% of cases, the isolated fungus was Alternaria alternata (Fr.:Fr.) Keissl, as identified by M. Priest, NSW Agriculture, Australia. The pathogenicity of A. alternata was determined on detached, freshly picked cones of hop cultivar “Nugget.” Cones (n = 25) were inoculated with a conidial suspension of the fungus (1,000 spores per ml) and incubated at room temperature in a sealed container on plastic mesh over tissue wetted with sterile distilled water. Symptoms first appeared three days after inoculation as necrotic tips of bracts and bracteoles, and within 10 days the entire cone had become necrotic. Symptoms were more severe in vitro compared to in the field. This was probably due to the maintenance of detached cones under constant high relative humidity. Disease symptoms did not appear on cones inoculated with sterile distilled water. The pathogen was reisolated from inoculated cones, completing Koch's postulates. The pathogenicity of A. alternata to hop cones was reported in the United Kingdom in 1988. To our knowledge, this is the first report of A. alternata on hop cones in Australia. References: (1) P. Darby. Trans. Br. Mycol. Soc. 90:650–653, 1988.
First Report of Colletotrichum acutatum on Strawberry in Finland
Authors: Parikka P. , Kokkola M. 
Published: May 2007

Strawberry (Fragaria × ananassa) is the most important small fruit crop in Finland. The quarantined pest Colletotrichum acutatum was detected for the first time on strawberry in August 2000, in Eastern Finland. Waiting-bed plants of cultivar Elsanta had symptoms typical of anthracnose rot (black spot) on the fruit, and small black lesions were seen on stolons. The rainy, warm, and humid weather of the summer favored the development and spread of the disease. C. acutatum was isolated from lesions on the fruit. Abundant sporulation was observed on lesions, and the fungus was readily isolated on potato dextrose agar (PDA) from surface-sterilized fruit pieces. Spores (11.5 to 19.8 × 3.3 to 4.0 μm) were acute at both ends, and acervuli with salmon pink spore masses matched the descriptions of C. acutatum (1). At first, the colonies were white and later became ash gray. The growth rate of the fungus was 8.0 to 8.8 mm per day, at 27°C. The identification was confirmed with enzyme-linked immunosorbent assay at the Central Science Laboratory, York, U.K. In order to fulfill Koch's postulates, young potted strawberry plants were inoculated by misting with a suspension of 10.4 × 106 conidia per ml of C. acutatum. Healthy runner plants of micropropagated cultivars Bounty, Cudaruska, Jonsok, Korona, and Oka (10 plants of each cultivar) were inoculated and incubated for 3 days, at 100% relative humidity. After 3 weeks at 20 to 21°C and 16 h of light per day, dark, elongated lesions measuring 2 to 15 mm were observed on the stolons. All tested cultivars developed symptoms on stolons and petioles, but no crown infections were detected. Flowering and fruit-bearing plants of cultivars Honeoye, Sara, and Senga Sengana were similarly inoculated and incubated. The first symptoms of fruit rot were detected 5 days after inoculation on the ripening fruit of Honeoye. Less severe fruit rot was seen on the fruit of Senga Sengana and the Fragaria vescana cultivar Sara. Salmon pink sporodochia developed on infected fruit, stolons, and leaves, within 5 days on moist filter paper, and C. acutatum was isolated on PDA. No other pathogens were present. Because C. acutatum is a quarantined pest in Finland, all strawberry plants of the infected lot on this particular farm were destroyed and future use of the field will be restricted. Reference: (1) C. M. Howard et al. 1992. Plant Dis. 76:976–981.
First Report of Occurrence of Verticillium Wilt on Some Ornamental Trees in Sicily
Authors: Polizzi G. , Vitale A. , Catara V. 
Published: May 2007

In July 1998, a widespread lethal collapse of butterfly tree (Bauhinia purpurea L.), puka tree (Meryta sinclairii Hook.), Indian laurel (Ficus microcarpa L.), golden rain tree (Koelreuteria paniculata Laxm.), and Brazilian pepper tree (Schinus terebinthifolius Raddi.) has been observed in an ornamental growing area near Catania in eastern Sicily. The diseased plants showed yellowing of the leaves and twig dieback. In cross sections of infected trunks, roots, twigs or shoots, characteristic discoloration of xylem vessels was observed, resembling a vascular wilt disease. The disease was chronic with a lingering decline progressing for years. The isolate that was consistently recovered from diseased tissues on PDA was identified as Verticillium dahliae Kleb., based on verticillate conidiophores with phialides and conidia and melanized microsclerotia. Pathogenicity tests were performed on 4- to 6-month-old seedlings of all five ornamental plants by inoculating a suspension of the fungus (1). Symptoms were observed after 5 to 7 months, and V. dahliae was reisolated, confirming Koch's postulates. To our knowledge this is the first report of V. dahliae on Indian laurel, golden rain tree, and Brazilian pepper tree in Italy, and the first report of the disease on butterfly tree and puka tree. Reference: H. A. Melouk and C. E. Horner. Phytopathology 65:767, 1975.
First Report of Columbia Root-Knot Nematode (Meloidogyne chitwoodi) in Potato in New Mexico
Authors: Thomas S. H. , Sanderson S. A. , Handoo Z. A. 
Published: May 2007

Following a report of Columbia root-knot nematode in potatoes (Solanum tuberosum L.) imported by Mexico from the United States in spring 2000, six fields in San Juan County, NM, were surveyed in August 2000. Soil samples from two fields in which the exported potatoes had been produced contained second-stage juveniles that were tentatively identified as Columbia root-knot nematode. During the 2000 potato harvest, state inspectors detected tubers from four additional fields that exhibited symptoms of Columbia root-knot nematode, including warty exteriors and discrete small brown lesions that were apparent to a depth of 1 cm below the tuber surface. Meloidogyne chitwoodi Golden et al. (1) was confirmed from a subsample of tubers sent to the USDA Nematology Laboratory in Beltsville, MD, in October 2000. Identification was based on morphological examination of the nematodes recovered from tubers. To our knowledge, this is the first report of M. chitwoodi from New Mexico. No Columbia root-knot nematodes were recovered from soil samples collected at 26 locations throughout San Juan County in 1988 and 1989, nor had symptomatic tubers or plants been observed in this area previously. Columbia root-knot nematode most likely represents a recent introduction into northwestern New Mexico. Additional information regarding distribution of this nematode within the region is needed. References: (1) A. M. Golden et al. J. Nematol. 12:319–327, 1980.
Association of a Monopartite Begomovirus with Yellow Mosaic Disease of Pumpkin (Cucurbita maxima) in India
Authors: Singh R. , Raj S. K. , Chandra G. 
Published: May 2007

Pumpkin (Cucurbita maxima) is an economically important vegetable crop of the family Cucurbitaceae. Yellow mosaic in C. maxima was observed in and around Lucknow, India, during the winter season of 1999-2000. High populations of whiteflies (Bemisia tabaci) were associated with diseased plants. Whiteflies were allowed to feed on diseased C. maxima plants and placed on healthy C. maxima seedlings. Symptoms of yellow mosaic disease were successfully reproduced in the seedlings. These results suggested a possible involvement of a geminivirus with the disease. Total DNA was extracted from infected and uninfected C. maxima seedlings by the CTAB method. DNA samples were used as templates in polymerase chain reaction (PCR) using degenerate primers A (5′-TAATATTACCKGWKGVCCSC-3′) and B (5′-TGGACYTTRCAWGGBCCT TCACA-3′), which have been designed to amplify a region of about 500 to 600 nt from DNA-A of a majority of begomoviruses (1). The PCR products obtained were analyzed on a 1.5% agarose gel. The major amplicon obtained from the DNA of infected plants was about 550 bp as expected from these primers. However, no such amplicon was observed in DNA samples from uninfected plants. The amplicon obtained from PCR was cloned in a suitable cloning vector. Three separate clones were sequenced and the corrected sequence data (GenBank Accession No. AF381977) was compared with the corresponding sequences of other known geminiviruses. The highest identity (88%) was with a strain of monopartite Tomato leaf curl virus (TLCV) from southern India (GenBank Accession No. U38239). The first 34 nucleotides showed significant identity (91% and 97%, respectively) with Althea rosea enation mosaic virus (GenBank Accession No. AF014881) and TLCV strain D2 reported from Australia (GenBank Accession No. AF084006), both of which are monopartite begomoviruses. These results establish the provisional identity of the pathogen causing yellow mosaic disease on pumpkin in India as a closely related strain of the monopartite TLCV. The yellow leaf disease of muskmelon in Thailand and watermelon leaf curl disease in Pakistan also were recently reported to be caused by an Indian strain of TLCV (2,3). However, to our knowledge this is the first report of detection of a monopartite geminvirus causing yellow mosaic disease on pumpkin in India. References: (1) D. Deng et al. Ann. Appl. Biol. 125:327, 1994. (2) S. H. Khan et al. Plant Dis. 84: 102, 2000. (3) K. Sarmretwanich, Plant. Dis. 84:707, 2000.
First Report of Tan Spot on Wheat in Pakistan
Authors: Ali S. , Francl L. J. , Iram S. , Ahmad I. 
Published: May 2007

Tan spot is caused by Pyrenophora tritici-repentis and is an economically important foliar disease of wheat worldwide. The fungus produces two types of symptoms, necrosis and chlorosis, on susceptible wheat cultivars. Isolates have been grouped into five races based on their ability to induce necrosis (nec+) and chlorosis (chl+) on appropriate wheat differentials (1,2). During March 2000, foliar diseases of wheat were surveyed in major wheat-growing areas of the Punjab Province of Pakistan. Tan spot was observed at 13 locations in the province. Diseased leaf samples were collected from all 13 locations to satisfy Koch's postulates. Isolations were made by placing 2-cm-long diseased leaf pieces in petri dishes with three layers of dampened Whatman No. 1 filter paper. The leaf pieces were incubated under an alternating cycle of 24 h of light at 21°C and 24 h of dark at 16°C. A fungus that produced erect, single dark yellow-brown conidiophores with single light yellow-brown conidia was recovered from all the samples and identified as Drechslera tritici-repentis, the anamorph of Pyrenophora tritici-repentis. Single spores were transferred on V8 potato dextrose agar for further study. Seven single spore isolates recovered from the samples were imported through APHIS and tested for pathogenicity and race structure in a growth chamber at North Dakota State University. Two-week-old seedlings of wheat differentials were inoculated individually with a spore suspension of each isolate, and consistent results were found in four replicated experiments. Four of seven isolates were identified as race 1 (nec+chl+), whereas, three isolates did not correspond to any of the currently identified five races. For all these isolates, one of the differentials (Katepwa), which exhibits necrosis, chlorosis, or neither symptom to the five described races, showed both necrosis and chlorosis. This is the first report of the occurrence of tan spot of wheat in Pakistan. The widespread presence of tan spot in the region is a potential threat to wheat production. References: (1) De Wolf et al. Can. J. Plant Pathol. 20:349, 1998. (2). Lamari et al. Can. J. Plant Pathol. 17:312, 1995.
First Report of Tomato yellow leaf curl virus Infecting Pepper Plants in Cuba
Authors: Quiñones M. , Fonseca D. , Martinez Y. , Accotto G. P. 
Published: May 2007

The begomovirus Tomato yellow leaf curl virus (TYLCV) is one of the major threats to tomato production in tropical and subtropical regions worldwide. TYLCV was found in Cuba in 1994 and later became the most serious constraint to tomato production (2). During a field survey in 2001, pepper plants (Capsicum annuum) were observed in a greenhouse in Camagüey Province, showing mild interveinal yellowing and curling of leaves. Total nucleic acids were extracted from these plants and from pepper samples collected in previous years that showed similar symptoms. Polymerase chain reaction (PCR) was performed on extracts using a primer pair (TY-1/TY-2) (1) specific for the capsid protein (CP) gene of begomoviruses and a second primer pair (IR2353+: CTGAATGTTTGGATGGAAATGTGC; IR255-:GCTCGTAAGTTTCCT CAACGGAC) designed to amplify the part of the genome encompassing the intergenic region (IR) of the Cuban isolate of TYLCV-IS (2). With these primer pairs, amplicons of the expected size were obtained from five samples (one collected in 1995 in Havana Province, two in 1999 in Sancti Spiritus, and two in 2001 in Camagüey.) The CP fragment was digested with RsaI, while the IR amplicon was digested with AvaII and EcoRI. In all cases the patterns obtained corresponded to digestion patterns for identical PCR fragments obtained from TYLCV-infected tomatoes. The IR amplicon sequence from one sample showed ≈99% identity with the corresponding region of the TYLCV-IS isolated from tomato in Cuba. To our knowledge, this is the first report of TYLCV-IS infection in peppers in Cuba. References: (1) G. P. Accotto et al. Eur. J. Plant. Pathol. 106:179, 2000. (2) Y. Martínez et al. J. Phytopathol.144:277, 1996.
First Report of Tobacco Bushy Top Disease in China
Authors: Mo X.-H. , Qin X.-Y. , Tan Z.-X. , Li T.-F. , Wu J.-Y. , Chen H.-R. 
Published: May 2007

In 1993, a severe epidemic of a new disease of flue-cured tobacco (Nicotiana tabacum) occurred in western Yunnan Province, People's Republic of China. Since then, over 40,000 ha of tobacco have been affected, with an average incidence of ≈15%. Infected plants were stunted, and leaves showed symptoms of vein distortion, vein clearing, mottling, and rounding. Axillary buds sprouted from the main stem of infected plants early and formed lateral shoots, on which other shoots were produced. As a result, the infected plants presented the characteristic “bushy” appearance. Aphid- (Myzus persicae (Sulzer)) and sap-transmission experiments were conducted. In aphid-transmission tests, after an acquisition feeding period of 24 h on diseased tobacco, the shortest test feeding that resulted in infection was 5 min. The causal agent(s) was readily sap-transmissible, but it could not be transmitted from sap-inoculated plants to healthy plants by aphids. Thirty-two species of plants in eleven families were tested by sap-inoculation for infectivity to alternative hosts by the casual agent(s). All the species of Nicotiana tested were infected. All the hosts were restricted to the solanaceae. The symptoms, transmission, and host range of this disease were identical to those of tobacco bushy top disease in Zimbabwe (1). Using umbravirus-specific primers (3), a 550-bp DNA fragment was amplified by reverse transcription-polymerase chain reaction (RT-PCR) from diseased tobacco, whose sequence (GenBank Accession No. AF402620) indicated the occurrence of an umbravirus. The results coincided with the taxonomic status of Tobacco bushy top virus, one of the causal agents of tobacco bushy top disease (1), a tentative species of the genus Umbravirus (2). To our knowledge, this is the first report of tobacco bushy top disease in China and the first report of a large outbreak of the disease outside sub-Saharan Africa. References: (1) L. F. Gates. Ann. Appl. Biol. 50:169, 1962. (2) F. A. Murphy. et al. Page 388 in: Virus Taxonomy: Sixth Report of the International Committee on Taxonomy of Viruses, Page 388, 1995. (3) P. Vercruysse et al. J. Virol. Methods 88:153, 2000.