bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crown and Root Infection of Lisianthus Caused by Fusarium solani in South Africa
Authors: Truter M. , Wehner F. C. 
Published: May 2007

Cultivation of lisianthus (Eustoma grandiflorum (Raf.) Shinn.) is a minor industry in South Africa, with only a few growers producing the crop commercially. Commercial production at a location in Gauteng Province is hampered by rotting of the crowns and roots of plants that result in mortality of as much as 22% of the plants. At advanced stages of infection, the crowns of affected plants characteristically are covered with masses of fusoid, curved hyalophragmospores. Crowns and roots of symptomatic plants that were submitted by the grower in January 2003 were surface disinfested by immersing for 2 min in a 3% solution of sodium hypochlorite, and segments excised from the plant tissue were plated on potato dextrose agar supplemented with 50 mg l-1 of rifampicin. Fusarium solani (Mart.) Appel & Wollenw. (1), was consistently and exclusively isolated from the segments. Teleomorph Nectria haematococca Berk. & Broome, commonly developed in culture after incubation for 4 to 6 weeks, although no sexual structures were observed on infected plants. A spore suspension containing 104 micro- and macroconidia ml-1 was prepared for each of two single-conidial isolates of F. solani. Using a 0.8-mm-diameter hypodermic needle, 100 μl of each suspension was injected subepi-dermally into the crown of each of three 1-month-old disease-free lisian-thus plantlets (cv. Texas Blue Bell) growing in 500-ml plastic pots filled with sterilized vermiculite. In addition, each suspension was incorporated at 2% (vol/vol) into three pots with sterile vermiculite, and a plantlet was planted in each pot. Control plantlets were treated similarly, but with sterile distilled water. All inoculated plantlets developed crown rot and wilted within 2 weeks while maintained at 28°C in a greenhouse, regardless of mode of inoculation, and F. solani was readily reisolated from their crowns and roots. Control plantlets remained symptomless and did not yield F. solani. Crown and root infection of lisianthus by F. solani has been described (2,3), but to our knowledge, this is the first report of the disease in South Africa. References: (1) P. E. Nelson et al. Fusarium species: An Illustrated Manual for Identification. Pennsylvania State University Press, University Park. 1983. (2) J. J. Taubenhaus and W. N. Ezekiel. Phytopathology 24:19, 1934. (3) S. Wolcan et al. Plant Dis. 85:443, 2001.
First Report of Bean yellow mosaic virus (Pea Mosaic Strain) in Verbena × hybrida
Authors: Guaragna M. A. , Jordan R. L. , Putnam M. L. 
Published: May 2007

Verbena × hybrida is an ornamental annual used in rock gardens as an edging plant and hanging baskets. It comes in a variety of colors and grows approximately 1.5 to 2.5 cm (6 to 10 inches) high. In the spring of 2002, verbena cv. Lavender Shades plants from California showing leaf mosaic symptoms tested positive for potyvirus using an antigen-coated plate enzyme-linked immunosorbent assay with our genus Potyvirus broad spectrum reacting PTY-1 monoclonal as the detecting antibody (3). The virus was transmitted mechanically to Nicotiana benthamiana by sap inoculation from infected verbena plants. Infected tobacco showed systemic mild mosaic symptoms. Total RNA extractions from infected verbena and tobacco leaves were used in reverse transcription-polymerase chain reaction (RT-PCR) assays with generic potyvirus-specific primers that amplify highly conserved 700-bp or 1,600-bp fragments from the 3′ terminus of most potyviruses. This region includes the 3′ noncoding region (3′NCR) and the potyviral coat protein (CP). The PCR-amplified fragments were cloned by using standard TA cloning procedures and sequenced using dye-terminator chemistry. The cloned nucleotide and putative coat protein amino acid sequences from the infected verbena and tobacco plants were compared with the corresponding regions of other potyviruses. Amino acid comparison of the CP region of the verbena po-tyvirus showed 95 to 96% identity to four pea mosaic strains (PMV) of Bean yellow mosaic virus (BYMV), 85 to 89% identity to 20 other strains of BYMV, 74 to 76% identity with six strains of Clover yellow vein virus (CYVV), and only 50 to 64% identity with 28 other potyviruses. Pairwise comparisons among and between the CP sequences of PMV, BYMV, CYVV, and other potyviruses revealed identities of 92 to 99% for BYMV∷ BYMV, PMV∷PMV, and CYVV∷CYVV; 84 to 89% for BYMV∷ PMV, 69 to 78% for BYMV∷CYVV and PMV∷CYVV, and 50 to 64% for all other potyvirus combinations. Additionally, similar pairwise analysis of the 3′NCR of the verbena potyvirus revealed 98 to 99% identity to PMV strains, 81 to 94% to other BYMVs, 68 to 75% to CYVVs, and 52 to 64% with other potyviruses. Other 3′NCR pairwise comparisons generally revealed the same identity trend as described for the CP. Further serological analysis with our panel of BYMV-specific, BYMV-subgroup, and potyvirus cross-reactive monoclonal antibodies (3) confirmed the designation of the verbena potyvirus isolate as a pea mosaic strain of BYMV. To our knowledge this is the first confirmed report of BYMV-pea mosaic strain in Verbena (1,2). References: (1) Agdia, Inc. Positive Ornamental Plant Samples. Agdia On-line Publication, 2003. (2) A. A. Brunt et al. Verbena hybrida. Plant Viruses Online: Descriptions and Lists from the VIDE Database. Version 20. On-line publication, August 1996. (3) R. L. Jordan, and J. Hammond. J. Gen. Virol. 72:1531, 1991.
First Report of Strawberry latent ringspot virus in Strawberry in the United States and Canada
Authors: Martin R. R. , Tzanetakis I. E. , Barnes J. E. , Elmhirst J. F. 
Published: May 2007

Strawberries in southern California have shown decline symptoms during the last 2 years. More than 70% of plants tested in California were infected with two newly identified criniviruses that infect strawberry (Strawberry pallidosis and Beet pseudo-yellows). Strawberry cultivars are usually symptomless when infected with one virus, and testing for other strawberry viruses is performed to identify any other viruses that may be involved in the symptomatology. Primers SLRSV F (5′ CCTCTCCAACC-TGCTAGACT 3′) and SLRSV R (5′ AAGCGCATGAAGGTGTAACT 3′) that amplify a 497-bp fragment of RNA 2 of Strawberry latent ringspot virus (SLRSV) were developed and utilized for reverse transcription-polymerase chain reaction (RT-PCR) detection. SLRSV belongs to the family Sequiviridae and is transmitted by nematodes of the genus Xiphinema. The virus has a broad host range (4) and is usually symptomless in strawberries. Strawberry plants from commercial fields in California, Oregon, Washington, and British Columbia, Canada were tested. SLRSV was identified in 17% of plants tested from California and 4% of plants tested from British Columbia, while all samples from Oregon and Washington tested negative. The fragment amplified (GenBank Accession No. AY461735, isolate from British Columbia, Canada) shares 84% nucleotide and 94% amino acid sequence identity with the previously published sequence of SLRSV from strawberry (GenBank Accession No. X77466) (3). The virus was transmitted mechanically from strawberry samples from Canada to Chenopodium quinoa, and the infected C. quinoa plants tested positive for SLRSV with RT-PCR, while no amplicons were obtained from noninoculated control plants. To our knowledge, this is the first report of SLRSV in strawberry in North America, although it has been previously reported in a single cherry tree in Ontario, Canada (1) and in an imported seed lot of parsley in California (2). The number of plants that tested positive as well as the geographic distribution of the virus indicates that the virus is widespread in California, but further testing is needed to identify its distribution in other states. References: (1) W. R. Allen et al. Phytopathology 60:1262, 1970. (2) C. M. Hanson and R. N. Campbell. Plant Dis. Rep. 63:142, 1979. (3) S. Kreiah et al. J. Gen. Virol. 75:2527, 1994. (4) K. Schmelzer. Phytopath. Z. 66:1, 1969.
First Report of the Root-Knot Nematode Meloidogyne ethiopica on Tomato in Slovenia
Authors: Širca S. , Urek G. , Karssen G. 
Published: May 2007

The root-knot nematode Meloidogyne ethiopica Whitehead originally described from Tanzania is also distributed in South Africa, Zimbabwe, and Ethiopia (3). Although this species is a relatively unknown root-knot nematode, M. ethiopica parasitizes several economical important crops, such as tomato, cowpea, bean, cabbage, pepper, pumpkin, tobacco, lettuce, and soybean (4). This species can be morphologically confused with M. incognita (Kofoid & White), and therefore, is probably easily overlooked (1). Recently, characteristic esterase isozyme patterns were described for this species, which provide a more reliable identification (2). In October 2003, Lycopersicum esculentum cv. Belle plants with large root-galls were observed in a greenhouse at Dornberk, Slovenia, which were identified as an unknown root-knot nematode within the M. incognita group. Subsequent sampling revealed infestation of all tomato plants within this greenhouse with obvious aboveground symptoms of stunting and wilting. Additional morphological and isozyme studies identified this root-knot nematode as M. ethiopica. The identification was based on female, male, and second-stage juvenile morphology and malate dehydrogenase and esterase isozyme phenotypes from young egg-laying females isolated from 20 tomato plants and compared with a culture of M. ethiopica from Africa. To our knowledge, this is not only the first report of M. ethiopica in Slovenia, but also the first report of this species in Europe. References: (1) A. M. Golden. Fundam. Appl. Nematol. 15:189, 1992. (2) W. Mandefro and K. Dagne. Afr. J. Plant Prot. 10:39, 2000. (3) A. G. Whitehead. Trans. Zool. Soc. Lond. 31:263, 1968. (4) A. G. Whitehead. Nematologica 15:315, 1969.
First Report of Powdery Mildew Caused by Erysiphe aquilegiae var. aquilegiae on Aquilegia flabellata in Italy
Authors: Garibaldi A. , Bertetti D. , Gullino M. L. 
Published: May 2007

Aquilegia flabellata Sieb. and Zucc. (columbine) is a perennial garden species belonging to the family Ranunculaceae. During the summer of 2003, a severe outbreak of a previously unknown powdery mildew was observed in several gardens near Biella (northern Italy). Upper surfaces of leaves were covered with a white mycelium and conidia, and as the disease progressed infected leaves turned yellow and died. Foot cell was cylindric and appressorium lobed. Conidia were hyaline, ellipsoid, and measured 31.2 to 47.5 × 14.4 to 33 μm (average 38.6 × 21.6 μm). Fibrosin bodies were not present. Cleistothecia were globose, brown, had simple appendages, ranged from 82 to 127 (average 105) μm in diameter, and contained one to two asci. Ascocarp appendages measured five to eight times the ascocarp diameter. Asci were cylindrical (ovoidal) and measured 45.3 to 58.2 × 30.4 to 40.2 μm. Ascospores (three to four per ascus) were ellipsoid or cylindrical and measured 28.3 to 31.0 × 14.0 to 15.0 μ;m. On the basis of its morphology, the pathogen was identified as Erysiphe aquilegiae var. aquilegiae (1). Pathogenicity was confirmed by gently pressing diseased leaves onto leaves of five, healthy A. flabellata plants. Five noninoculated plants served as controls. Inoculated and noninoculated plants were maintained in a garden where temperatures ranged between 20 and 30°C. After 10 days, typical powdery mildew symptoms developed on inoculated plants. Noninoculated plants did not show symptoms. To our knowledge, this is the first report of the presence of powdery mildew on Aquilegia flabellata in Italy. E. communis (Wallr.) Link and E. polygoni DC. were reported on several species of Aquilegia in the United States (2), while E. aquilegiae var. aquilegiae was previously observed on A. flabellata in Japan and the former Union of Soviet Socialist Republics (3). Specimens of this disease are available at the DIVAPRA Collection at the University of Torino. References: (1) U. Braun. Nova Hedwigia, 89:700, 1987. (2) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St Paul, MN, 1989. (3) K. Hirata. Host Range and Geographical Distribution of the Powdery Mildews. Faculty of Agriculture, Niigata University, 1966.
First Report of Powdery Mildew Caused by an Oidium sp. on Papaver nudicaule in Italy
Authors: Garibaldi A. , Minuto A. , Bertetti D. , Gullino M. L. 
Published: May 2007

Iceland poppy (Papaver nudicaule L.) is grown on the Italian Riviera for export as a cut flower and its importance in the industry is increasing. During the spring of 2003, severe outbreaks of powdery mildew that had not been reported previously, occurred in several commercial plantings grown outdoors in containers near Imperia in northern Italy. Mycelium was observed on all green organs of the plant (leaves, stems, and petioles). Both surfaces on the leaves were affected, and heavily colonized leaves were distorted. As the disease progressed, diseased leaves turned yellow and died. The disease did not affect the flowers. Conidia were hyaline, cylindric, and measured 10.8 to 29.8 × 16.8 to 48.0 μm (average 13.7 × 37.3 μm). Foot cells were cylindric and appressoria unlobed. Fibrosin bodies were not present, and cleistothecia were not observed. The pathogen was identified as Oidium sp. subgenus Pseudoidium (1,2). Pathogenicity was confirmed by gently pressing leaves with visible sporulation onto the leaves of five 90-day-old P. nudicaule plants that were healthy and free of symptoms. Five noninoculated healthy plants served as controls. Inoculated and noninoculated plants were maintained in a growth chamber at 15°C with a 12-h photoperiod. After 7 to 10 days, typical symptoms of powdery mildew developed on inoculated plants but not on noninoculated plants. Previously, Erysiphe cruciferarum Opiz ex L. Junell has been reported on P. nudicaule in all continents, and E. cichoracearum DC. and E. polygoni DC. have been reported in several countries, including Italy, as a causal agent of powdery mildew on other species of Papaver including P. rhoeas and P. strigosum. To our knowledge, this is the first report of powdery mildew caused by an Oidium sp. on P. nudicaule in Italy. The voucher specimen is kept in the department collection at the University of Torino. References: (1) R. Belanger et al., eds. The Powdery Mildew A Comprehensive Treatise. The American Phytopathological Society, St Paul, MN, 2002. (2) U. Braun. Nova Hedwigia. 89:700, 1987.
First Report of the Reniform Nematode Rotylenchulus reniformis on Cotton in Virginia
Authors: Eisenback J. D. , Hopkins Nina , Phipps P. M. 
Published: May 2007

In Virginia during September 2002, the reniform nematode, Rotylenchulus reniformis Linford and Oliveira (1), was found for the first time following a grower's concern about poor growth and yield of cotton (Gossypium hirsutum L.) cv. Fiber Max 989BR. The infested field was planted with cotton each year for the last eight growing seasons. The field was located on Hall Road in Southampton County, Virginia at coordinates 77°16′28.8926″W, 36°37′10.6428″N near the town of Branchville. The soil was loamy sand, which is typical of sandy textured soils in the region. Rainfall from May to September at a nearby weather station was nearly 50% below normal, which may have contributed to the suppression of plant growth. The vermiform nematodes were extracted with a North Carolina State University model semiautomatic elutriator and centrifugation/sugar flotation. Populations were 30 to 150 per 500 cm3 of soil in areas with noticeable stunting. Cultures were established on cotton cv. Delta Pine 64 and tomato (Lycopersicon esculentum Mill. cv. Rutgers) and were maintained in a greenhouse. Reproduction was moderate on cotton and high on tomato. Identifications were based on morphology and measurements of vermiform females and males: immature female length (L) = 407 ± 22 (376 to 418) μm, stylet L = 18.5+1.7 (17.0 to 21.3) μm; and male L = 351 ± 17 (339 to 367) μm. Voucher specimens were placed and are maintained in the Virginia Tech Nematode Collection. Reference: (1) M. B. Linford and J. M. Oliveira. Proc. Helminthol. Soc. Wash. 7:35, 1940.
Watermelon as a New Host of Pseudomonas viridiflava, Causal Agent of Leaf and Stem Necrosis, Discovered in Turkey
Authors: Mirik M. , Aysan Y. , Cetinkaya-Yildiz R. , Sahin F. , Saygili H. 
Published: May 2007

Severe leaf and stem necrosis symptoms were observed on watermelon seedlings (Citrullus lanatus cv. Euroca) in Adana, Turkey during a warm and humid period in January 2004. Streak-plate isolations were made from leaf and stem lesions on King's medium B. A fluorescent, yellowish mucoid, gram-negative, and oxidase-, levan- and arginin dihydrolase-negative bacterium was consistently isolated from diseased plant samples. All seven representative strains isolated were pectolytic on potato slices and hypersensitive reaction positive on tobacco leaves. The result of LOPAT tests and morphology of the strains were different from Pseudomonas syringae pathovars. The strains produced acid from sorbitol, fructose, glucose, L (+) arabinose, D (+) xylose, D (-) mannitol, but not from D (+) sucrose, trehalose, maltose, melibiose, lactose, and D (-) arabinose. Utilization of D (-) tartrate was positive. Incubation was at 28°C, and the results of the tests were evaluated 7 days after inoculation. Fatty acid analysis (Ataturk University, Erzurum, Turkey) confirmed the bacterial strains as P. viridiflava with a similarity index of 83 to 86% (3). The strains were pathogenic on watermelon, melon, and tomato plants with needle inoculation of bacterial suspensions containing 108CFU ml-1 in a 0.85% saline. Water-soaking and stem necrosis symptoms were observed on the inoculated plants 5 to 7 days after inoculation. The bacterium was readily reisolated from inoculated plants and identified as strains of P. viridiflava, which has been previously reported as a pathogen of melon grown in Turkey (1) and Greece (2). To our knowledge, this is the first study demonstrating the occurrence and outbreak of leaf and stem necrosis disease caused by P. viridiflava on watermelon in the world. References: (1) A. Aysan et al. Plant Pathol. 52:800, 2003. (2) D. E. Goumans and A. K. Chatzaki. Eur. J. Plant Pathol. 104:181, 1998. (3) J. D. Janse et al. Syst. Appl. Microbiol. 15:538, 1992.
First Report of Phytoplasma Infection in Hop Plants
Authors: Solarska E. , Kamińska M. , Śliwa H. 
Published: May 2007

Disease symptoms of severe shoot proliferation resembling phytoplasmal disease symptoms were observed in early spring of 2003 in hop (Humulus lupulus L.) plant cvs. Magnum and Marynka that were grown in a commercial farm in Poland. Proliferation of shoots has not been previously reported in hop plants. To detect the presence of phytoplasmas in hops, young shoots from four symptomatic (two cultivars) and two symptomless (‘Magnum’) plants were assayed for phytoplasma 16S rDNA using polymerase chain reaction (PCR). In addition, leaf samples from healthy Catharanthus roseus plants and plants experimentally infected with the reference strains of aster yellows phytoplasma (AY1, group 16SrI-B) or apple proliferation phytoplasma (AP, group 16SrX-A) were included for comparison. Amplifications were performed using the universal phytoplasma primer pair P1/P7 in an initial assay, and universal primer pairs fA/rA (1), Pc399/P1694, or R16F2n/R16R2 (2) and group specific primer pair R16(I)F1/R16(I)R1 (3) in a nested reaction. Specific products were obtained in direct PCR with the universal primer pairs P1/P7 only for the control samples of the reference strains AY and AP. No visible product was amplified by the direct PCR from samples obtained from hops and healthy periwinkle plants. However, in nested PCR with primer pairs P1/P7 followed by primer pairs fA/rA, R16F2n/R16R2, Pc399/P1694, or R16(I)F1/R16(I)R1, specific DNA bands were observed from naturally infected hop plants (both four symptomatic and two symptomless) tested. No amplification products were observed from healthy periwinkle plants. The specificity of PCR products (obtained with universal R16F2n/R16R2 primer pair) was confirmed by restriction fragment length polymorphism (RFLP) analysis using AluI, MseI, HhaI, and RsaI for enzymatic digestion. RFLP patterns of these rDNA fragments for samples of naturally infected hops and for AY1 reference strain were similar and were characteristic of phytoplasma 16SrI-B subgroup. To our knowledge, this is the first evidence that hop shoot proliferation disease is associated with natural infection by phytoplasmas. Furthermore, detection of phytoplasma in asymptomatic hops underscores the need to fully elucidate the etiological role of this pathogen in the disease. References: (1) U. Ahrens and E. Seemüller. Phytopathology 82:828, 1992. (2) I.-M. Lee et al. Phytopathology 83:834, 1993. (3) I.-M. Lee et al. Phytopathology 84:559, 1994.
First Report of Alfalfa mosaic virus in Lavandula officinalis
Authors: Martínez-Priego Ll. , Córdoba M. C. , Jordá C. 
Published: May 2007

For several years, in ornamental nurseries in the Mediterranean area of Spain, stunting and yellow leaf spotting have been observed in young plants of Lavandula officinalis. Symptoms eventually disappeared as the plants matured. During the summer of 2003, the number of plantlets affected and the intensity of symptoms increased significantly. Symptomatic plants tested positive using enzyme-linked immunosorbent assay (ELISA) (Phyto-Diagnostics, INRA, France) for the presence of Alfalfa mosaic virus (AMV). ELISA results were verified using reverse transcription-polymerase chain reaction (RT-PCR). Total RNA extracts from symptomatic plants were analyzed using primers designed specifically for the coat protein region of AMV utilizing sequence data from GenBank Accession No. AF215664: AMVcoat-F: GT GGT GGG AAA GCT GGT AAA and AMVcoat-R: CAC CCA GTG GAG GTC AGC ATT. The thermocycling schedule was as follows: reverse transcriptase step at 50°C for 30 min, first PCR cycle at 94°C for 2 min, 35 cycles each of 30 s at 94°C, 30 s at 54°C, 30 s at 72°C, followed by a final extension at 72°C for 10 min. A 700-pb PCR product of the expected size was obtained from plants that were positive for AMV using ELISA. The two systems provide for rapid detection of AMV in L. officinalis. A regular screening program will assist in providing virus-free plants to ornamental nurseries. These results demonstrate the presence of AMV in L. officinalis. Alfalfa (Medicago sativa L.) is a typical source of AMV. However, because the nurseries where L. officinalis is grown are not in the vicinity of alfalfa fields, we suggest the source of the infection originated in the propagation material. AMV has currently been reported in L. officinalis only in Italy and France (1). To our knowledge, this is the first report of AMV in L. officinalis in Spain. Reference: (1): A. Garibaldi et al. Ed. Edagricole-Edisioni Agricole della Calderini s.r.l., Bologna, 2000.