bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Sclerotium rolfsii on Ascocentrum and Ascocenda Orchids in Florida
Authors: Cating R. A. , Palmateer A. J. , McMillan R. T. 
Published: August 2009

Southern blight caused by Sclerotium rolfsii is known to occur on several economically important orchid hosts, including Vanda species and hybrids (1–3). In the summer and fall of 2008, an outbreak of southern blight on Vanda orchids was seen in several commercial nurseries and landscapes throughout South Florida. More than a dozen orchids were affected at one of the locations, and symptoms of S. rolfsii were observed on Ascocentrum and Ascocenda orchids, which are also common in the trade and demand a resale value ranging from $20 to $150 for specimens in bloom. Affected Ascocentrum and Ascocenda orchids were found severely wilted at the apex, while around the base of the plants, tan, soft, water-soaked lesions were present. As the lesions progressed, leaves around the base of the plants began to fall off, leaving the stems bare. After 2 days, white, flabellate mycelium was seen progressing up the stem and numerous, tan-to-brown sclerotia were present. Leaves and portions of the stems were plated on acidified potato dextrose agar (APDA) and grown at 25°C. White, flabellate mycelium and tan sclerotia approximately 2 mm in diameter were produced in culture and microscopic examination revealed the presence of clamp connections. The fungus was identified as S. rolfsii and a voucher specimen was deposited with the ATCC. A PCR was performed on the ITS1, 5.8S rDNA, and ITS2 and the sequence was deposited in GenBank (Accession No. GQ358518). Pathogenicity of an isolate was tested by placing 6-mm plugs taken from APDA plates directly against the stem of five different Ascocentrum and Ascocenda orchids. Five Ascocentrum and Ascocenda orchids were inoculated with 6-mm plugs of plain APDA and five were untreated controls. Plants were housed under 50% shade, 60 to 95% humidity, and temperatures ranging from 75 to 88°F. Within 7 days, all inoculated plants developed symptoms that were identical to those observed on original plants and S. rolfsii was consistently reisolated from symptomatic tissue. Ascocentrum and Ascocenda were previously reported under miscellaneous orchid species and hybrids as hosts for S. rolfsii (1). However, this report was highly ambiguous and the most current edition does not report the host fungus combination (2). To our knowledge, this is the first report of S. rolfsii affecting Ascocentrum and Ascocenda orchids. References: (1) S. A. Alfieri, Jr., et al. Diseases and Disorders of Plants in Florida. Bull. No. 11. Division of Plant Industry, Gainesville, FL, 1984. (2) S. A. Alfieri, Jr., et al. Diseases and Disorders of Plants in Florida. Bull. No. 14. Division of Plant Industry, Gainesville, FL, 1994. (3) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989.
First Report of Barley yellow dwarf virus-MAV in Oat, Wheat, and Barley Grown in the Czech Republic
Authors: Kundu J. K. 
Published: August 2009

Barley yellow dwarf disease, a ubiquitous virus disease of cereal crops worldwide, is caused by a group of related, single-stranded RNA viruses assigned to Luteovirus (Barley yellow dwarf virus [BYDV] spp. PAV, PAS, MAV, and GAV) or Polerovirus (Cereal yellow dwarf virus-RPV) genera or unassigned to a genera (BYDV-SGV, BYDV-RMV, and BYDV-GPV) in the family Luteoviridae (1). Incidence of BYDV in cereal crops (e.g., barley, wheat, and oats) was high, and in recent years, reached epidemic levels in many regions of the Czech Republic. BYDV-PAV and BYDV-PAS have been identified in Czech cereal crops (2,4). Surveys of the incidence of BYDV were carried out using ELISA (SEDIAG SAS, Longvic, France) and one-step reverse transcription (RT)-PCR (Qiagen, Hilden, Germany) (2) during 2007 and 2008. Samples (125) were collected from different fields around the Czech Republic and 96 were BYDV positive. Three of the field isolates, CZ-6815, CZ-1561, and CZ-10844, from oat (Avena sativa; cv. Auron), winter wheat (Triticum aestivum; cv. Apache), and winter barley (Hordeum vulgare; cv. Merlot), respectively, were identified as BYDV-MAV by sequencing of the RT-PCR product (641-bp fragment) used to identify BYDV, which spanned 2839–3479 of the BYDV genome (GenBank Accession Nos. EF043235 and NC_002160) (2). The partial coat protein gene sequence of 483 nt was compared with the available sequences of 12 BYDV-PAV isolates (PAV-JP, PAV-NY, PAV-ILL, PAV-AUS, PAV-WG2, PAV-whG4y3, PAV-on21-4, Tahoe1, CA-PAV, HB3, FH3, and MA9501); nine BYDV-PAS isolates (PAS-129, PAS-64, WS6603, WG13, PAS-Tcb4-1, PASwaw5-9, FL2, PAS-Vd29, and PAS-MA9516); and six BYDV-MAV isolates (MAV-CA, MAV-PS1X1, MAV-Alameds268, LMB2a, SI-o4, and MAV-CN) by MEGA4 (3). Nucleotide and amino acid sequence identities for the three isolates ranged from 92.9 to 99.4% and 88.0 to 95.8%, respectively, for available BYDV-MAV isolates; 76.8 to 78.2% and 62.7 to 67.6%, respectively, for available BYDV-PAS isolates; and 77.6 to 79.3% and 65.5 to 70.4%, respectively, for available PAV isolates. The sequence data indicates that these isolates (CZ-6815, CZ-1561, and CZ10844; GenBank Accession Nos. FJ645747, FJ645758, and FJ645746, respectively) are BYDV-MAV. To my knowledge, this is the first record of BYDV-MAV in the Czech Republic. References: (1) C. J. D'Arcy and L. L. Domier. Page 891 in: Virus Taxonomy-8th Report of the ICTV. C. M. Fauquet et al., eds. Springer-Verlag, NY, 2005. (2) J. K. Kundu. Plant Dis. 92:1587, 2008. (3) K. Tamura et al. Mol. Biol. Evol. 24:1596, 2007. (4) J. Vacke. Page 100 in: Sbornik Referatu z Odborneho Seminare, Aktualni Problemy Ochrany Polnich Plodin, Praha, 1991.
First Report of Trichodorus variopapillatus (Nematoda: Trichodoridae) from the Czech Republic
Authors: Kumari S. , Decraemer W. 
Published: August 2009

Members of the Trichodoridae can cause substantial crop losses directly by feeding on plant roots and indirectly as vectors of tobraviruses; both vector and virus are polyphagous. In April of 2008, soil samples from the rhizosphere of Ulmus minor Mill in a deciduous broadleaf forest at Krivoklat yielded a population of Trichodorus variopapillatus Hooper, 1972. Nematodes were identified by morphological and morphometric characters as well as by molecular analysis. For classical identification, specimens were extracted from soil by a decanting-sieving method, heat killed and fixed in triethanolamine formalin, and processed and mounted in anhydrous glycerin. For molecular analysis, specimens were stored at –20°C in 1 M NaCl. Specimens largely agreed with T. variopapillatus (1,3). Average morphometric data of five male specimens are: body length 766 μm; body width 33 μm; onchiostyle length 55 μm; and spicule length 43 μm. Number of anterior ventromedian cervical papillae and number of precloacal supplements was three each. Spicules are regularly curved and the manubrium is knob-like. Morphometric data of two female specimens are: body length 663 and 858 μm; body width 29 and 38 μm; onchiostyle length 52 and 53 μm; V 54 and 57%. Refractive thickenings at the vulva are very large and quandrangular in shape in the lateral optical section. Identification of these nematodes was further verified by sequencing two regions of rDNA (18S gene and D2/D3 expansion segments of the 28S gene). Single female and male specimens from NaCl storage were transferred to 0.5-ml Eppendorf tubes containing 0.25M NaOH. Total genomic DNA was prepared by a rapid technique (4). The 18S gene was amplified in three fragments using the primer SSU_F_04 + SSU_R_09 (first fragment), SSU_F_22 + SSU_R_13 (second fragment), and SSU_F_23 + SSU_R_81 (third fragment). D2/D3 expansion segments of the large subunit of rDNA were amplified using the forward primer D2A and the reverse primer D3B (2). The regions were sequenced in both directions after purification of PCR products. The sequences of female and male specimens were identical. The sequences were deposited in GenBank with Accession Nos. GQ148719 (28S) and GQ148719 (18S). The length of 18S was 1,760 bp and D2/D3 was 786 bp. The obtained sequences were compared by BLAST in NCBI. The D2/D3 sequence is not available in GenBank for T. variopapillatus. The best BLAST hits were obtained with Trichodorus species. BLAST results of 18S sequence showed 5% divergence (76 substitutions) after trimming unequal ends with published sequence of T. variopapillatus Accession No. AY284841. All substitutions were confirmed from the chromatographs. To our knowledge, this is the first report of T. variopapillatus associated with U. minor in the Czech Republic. References: (1) W. Decraemer and P. Baujard. Fundam. Appl. Nematol. 21:37 1998. (2) P. De Ley et al. Nematology 1:591, 1999. (3) D. Hooper. Nematologica 17:59, 1972. (4) J. M. Stanton. Australas. Plant Pathol. 27:112, 1998.
First Report of Crenate Broomrape (Orobanche crenata) on White Lupine (Lupinus albus) Growing in Alkaline Soils in Spain and Egypt
Authors: Fernández-Aparicio M. , Emeran A. A. , Moral A. , Rubiales D. 
Published: August 2009

Crenate broomrape (Orobanche crenata Forsk.) is a parasitic weed known to threaten legume crops since antiquity. It is mainly restricted to the Mediterranean Basin, Southern Europe, and the Middle East where it is an important pest in grain and forage legumes and in some apiaceous crops such as carrot and celery (1). White lupines are cultivated in acid soils, which usually are free of O. crenata infestations. However, breeders are attempting to develop white lupine cultivars adapted to alkaline soils (2). We report here findings of O. crenata infection in field trials of this new lupine germplasm in alkaline soils in experimental farms with a known history of faba bean cultivation and heavy infestation of O. crenata in Kafr El-Sheikh, Egypt and Córdoba, Spain in the spring of 2009. Symptoms were typical of O. crenata infection with reduced growth and emergence of typical O. crenata nonbranched spikes close to the lupine plants. Infection was confirmed by digging up the plants to verify the attachment of the broomrape plant to the lupine. O. crenata plants growing on lupines were fully fertile, producing viable seeds. Plant morphology was typical of O. crenata (1). Voucher specimens were deposited at the Herbarium of the Botanic Department of the University of Córdoba. To our knowledge, this is the first report of O. crenata infecting lupine and is relevant because the expected introduction of alkaline-tolerant lupine cultivars will extend its area of cultivation into fields heavily infested with Orobanche. O. crenata is highly polymorphic and could easily adapt to, recognize, and infect this new host. Development of lupine-adapted O. crenata populations should be monitored because it could represent a major constraint on lupine introduction into alkaline soils. References: (1) D. M. Joel et al. Biology and Management of Weedy Root Parasites. Page 267 in: Horticultural Reviews. Vol. 33. John Wiley and Sons, Inc. Hoboken, NJ, 2007. (2) M. Vishnyakova and A. Mikic, White lupin (Lupinus albus L.) landraces and the breeding for tolerance to alkaline soil reaction. Page 142 in: Second GL-TTP Workshop: Integrating Legume Science and Crop Breeding. Novi Sad, Serbia, 2008.
Xiphinema rivesi from Chile Transmits Tomato ringspot virus to Cucumber
Authors: Auger J. , Leal G. , Magunacelaya J. C. , Esterio M. 
Published: August 2009

The dagger nematode, (Xiphinema rivesi Dalmasso), a member of the X. americanum group, was first reported in 2002 in Chile (3). X. rivesi is a vector of at least four North American nepoviruses including Cherry rasp leaf virus (CRLV), Tobacco ringspot virus (TobRSV), Tomato ringspot virus (TomRSV), and Peach rosette mosaic virus (PRMV) (2). TomRSV, first reported in Chile in 1984, was associated with raspberry decline and lately with brownline disease in D'Agen prune trees (1), however none of the Xiphinema spp. found in Chile have been reported to transmit this nepovirus. Two virus isolates, TomRSV (prune brownline isolate PBL-08) and Grapevine fanleaf virus (GFLV) (Yellow mosaic isolate GFLV-012), from the virus collection of the Departamento de Sanidad Vegetal, Universidad de Chile were used in transmission tests with a population of X. rivesi found in Chile. X. rivesi is not known to transmit GFLV and this virus was included as a check. The nematodes were extracted from soil from a D'Agen prune orchard, and transmission tests were done in compliance with the criteria proposed by Trudgill et al. (4). Cucumis sativus cv. National Pickling were grown in a growth chamber at 25°C and used as acquisition hosts and transmission bait plants. Acquisition hosts were mechanically inoculated with GFLV or TomRSV, displaying systemic symptoms in 15 to 20 days. Noninoculated cucumber plants were included as controls. Virus infection was confirmed by double-antibody sandwich (DAS)-ELISA before the introduction of nematodes to the soil. After a 20-day acquisition feeding period, the nematodes were wet screened from the soil and added to the healthy bait plants and allowed a 20-day inoculation feeding period. X. rivesi transmitted TomRSV but not GFLV. TomRSV bait plants developed systemic symptoms 5 weeks after the nematodes were transferred. Transmission of TomRSV was confirmed by testing leaf and root sap of bait plants in a DAS-ELISA. High virus concentrations were detected in the roots and leaves of TomRSV symptomatic plants. Bait plants on which nematodes had been allowed to feed following virus acquisition from GFLV-infected or from virus-free control plants tested negative by ELISA. No symptoms appeared on bait plants used for GFLV transmission or the control bait plants. To our knowledge, this is the first report of transmission of TomRSV with a Xiphinema population from Chile and South America. References: (1) J. Auger. Acta Hortic. 235:197, 1988. (2) D. J. F. Brown et al. Phytopathology 84:646, 1994. (3) G. Leal et al. Fitopatología 37:75, 2002. (4) D. L. Trudgill et al. Rev. Nematol. 6:133, 1983.
First Report of Curvularia lunata on Red-Fleshed Dragon Fruit (Hylocereus polyrhizus) in Malaysia
Authors: Hawa M. Masratul , Salleh B. , Latiffah Z. 
Published: August 2009

Red-fleshed dragon fruit (Hylocereus polyrhizus [Weber] Britton & Rose) is a newly introduced and potential crop in the Malaysian fruit industry. Besides its nutritious value, the fruit is being promoted as a health crop throughout Southeast Asia. In April of 2007, a new disease was observed in major plantations of H. polyrhizus throughout five states (Kelantan, Melaka, Negeri Sembilan, Penang, and Perak) in Malaysia with 41 and 25% disease incidence and severity, respectively. Stems of H. polyrhizus showed spots or small, circular, faint pink-to-beige necrotic lesions that generally coalesced as symptoms progressed. Symptom margins of diseased stem samples were surface sterilized with a 70% alcohol swab, cut into small blocks (1.5 × 1.5 × 1.5 cm), soaked in 1% sodium hypochlorite (NaOCI) for 3 min, and rinsed in several changes of sterile distilled water (each 1 min). The surface-sterilized tissues were placed onto potato dextrose agar (PDA) and incubated under alternating 12-h daylight and black light for 7 days. A fungus was consistently isolated from the stems of symptomatic H. polyrhizus and identified as Curvularia lunata (Wakker) Beodijn (1–3) that showed pale brown multicelled conidia (phragmoconidia; three to five celled) that formed apically through a pore (poroconidia) in sympodially, elongating, geniculated conidiophores. Conidia are relatively fusiform, cylindrical, or slightly curved, with one of the central cells being larger and darker (26.15 ± 0.05 μm). All 25 isolates of C. lunata obtained from diseased H. polyrhizus are deposited at the Culture Collection Unit, Universiti Sains Malaysia and available on request. Isolates were tested for pathogenicity by injecting conidial suspensions (1 × 106 conidia/ml) and pricking colonized toothpicks on 25 healthy H. polyrhizus stems. Controls were treated with sterile distilled water and noncolonized toothpicks. All inoculated plants and controls were placed in a greenhouse with day and night temperatures of 30 to 35°C and 23 to 30°C, respectively. Development of external symptoms on inoculated plants was observed continuously every 2 days for 2 weeks. Two weeks after inoculation, all plants inoculated with all isolates of C. lunata developed stem lesions similar to those observed in the field. No symptoms were observed on the control plants and all remained healthy. C. lunata was reisolated from 88% of the inoculated stems, completing Koch's postulates. The pathogenicity test was repeated with the same results. To our knowledge, this is the first report of C. lunata causing a disease on H. polyrhizus. References: (1) M. B. Ellis. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, Surrey, England, 1971. (2) R. R. Nelson and F. A. Hassis. Mycologia 56:316, 1964. (3) C. V. Subramanian. Fungi Imperfecti from Madras V. Curvularia. Proc. Indian Acad. Sci. 38:27, 1955.
MERE1, a Low-Copy-Number Copia-Type Retroelement in Medicago truncatula Active during Tissue Culture
Authors: Rakocevic Alexandra , Mondy Samuel , Tirichine Leïla , Cosson Viviane , Brocard Lysiane , Iantcheva Anelia , Cayrel Anne , Devier Benjamin , Abu El-Heba Ghada Ahmed , Ratet Pascal 
Published: August 2009

Abstract
We have identified an active Medicago truncatula copia-like retroelement called Medicago RetroElement1-1 (MERE1-1) as an insertion in the symbiotic NSP2 gene. MERE1-1 belongs to a low-copy-number family in the sequenced Medicago genome. These copies are highly related, but only three of them have a complete coding region and polymorphism exists between the long terminal repeats of these different copies. This retroelement family is present in all M. truncatula ecotypes tested but also in other legume species like Lotus japonicus. It is active only during tissue culture in both R108 and Jemalong Medicago accessions and inserts preferentially in genes.
Involvement of HbPIP2;1 and HbTIP1;1 Aquaporins in Ethylene Stimulation of Latex Yield through Regulation of Water Exchanges between Inner Liber and Latex Cells in Hevea brasiliensis
Authors: Tungngoen Kessarin , Kongsawadworakul Panida , Viboonjun Unchera , Katsuhara Maki , Brunel Nicole , Sakr Soulaiman , Narangajavana Jarunya , Chrestin Hervé 
Published: August 2009

Abstract
Natural rubber is synthesized in specialized articulated cells (laticifers) located in the inner liber of Hevea brasiliensis. Upon bark tapping, the laticifer cytoplasm (latex) is expelled due to liber tissue turgor pressure. In mature virgin (untapped) trees, short-term kinetic studies confirmed that ethylene, the rubber yield stimulant used worldwide, increased latex yield, with a concomitant decrease in latex total solid content, probably through water influx in the laticifers. As the mature laticifers are devoid of plasmodesmata, the rapid water exchanges with surrounding liber cells probably occur via the aquaporin pathway. Two full-length aquaporin cDNAs (HbPIP2;1 and HbTIP1;1, for plasma membrane intrinsic protein and tonoplast intrinsic protein, respectively) were cloned and characterized. The higher efficiency of HbPIP2;1 than HbTIP1;1 in increasing plasmalemma water conductance was verified in Xenopus laevis oocytes. HbPIP2;1 was insensitive to HgCl2 . In situ hybridization demonstrated that HbPIP2;1 was expressed in all liber tissues in the young stem, including the laticifers. HbPIP2;1 was up-regulated in both liber tissues and laticifers, whereas HbTIP1;1 was down-regulated in liber tissues but up-regulated in laticifers in response to bark Ethrel treatment. Ethylene-induced HbPIP2;1 up-regulation was confirmed by western-blot analysis. The promoter sequences of both genes were cloned and found to harbor, among many others, ethylene-responsive and other chemical-responsive (auxin, copper, and sulfur) elements known to increase latex yield. Increase in latex yield in response to ethylene was emphasized to be linked with water circulation between the laticifers and their surrounding tissues as well as with the probable maintenance of liber tissue turgor, which together favor prolongation of latex flow.
Heterotrimeric G Protein Signaling Is Required for Epidermal Cell Death in Rice
Authors: Steffens Bianka , Sauter Margret 
Published: August 2009

AbstractIn rice (Oryza sativa) adventitious root primordia are formed at the nodes as part of normal development. Upon submergence of rice plants, adventitious roots emerge from the nodes preceded by death of epidermal cells above the root primordia. Cell death is induced by ethylene and mediated by hydrogen peroxide (H2O2). Pharmacological experiments indicated that epidermal cell death was dependent on signaling through G proteins. Treatment with GTP-γ-S induced epidermal cell death, whereas GDP-β-S partially inhibited ethylene-induced cell death. The dwarf1 (d1) mutant of rice has repressed expression of the Gα subunit RGA1 of heterotrimeric G protein. In d1 plants, cell death in response to ethylene and H2O2 was nearly completely abolished, indicating that signaling through Gα is essential. Ethylene and H2O2 were previously shown to alter gene expression in epidermal cells that undergo cell death. Transcriptional regulation was not generally affected in the d1 mutant, indicating that altered gene expression is not sufficient to trigger cell death in the absence of Gα. Analysis of genes encoding proteins related to G protein signaling revealed that four small GTPase genes, two GTPase-activating protein genes, and one GDP dissociation inhibitor gene but not RGA1 were differentially expressed in epidermal cells above adventitious roots, indicating that Gα activity is regulated posttranscriptionally.
Involvement of a Broccoli COQ5 Methyltransferase in the Production of Volatile Selenium Compounds
Authors: Zhou Xin , Yuan Youxi , Yang Yong , Rutzke Michael , Thannhauser Theodore W. , Kochian Leon V. , Li Li 
Published: August 2009

AbstractSelenium (Se) is an essential micronutrient for animals and humans but becomes toxic at high dosage. Biologically based Se volatilization, which converts Se into volatile compounds, provides an important means for cleanup of Se-polluted environments. To identify novel genes whose products are involved in Se volatilization from plants, a broccoli (Brassica oleracea var italica) cDNA encoding COQ5 methyltransferase (BoCOQ5-2) in the ubiquinone biosynthetic pathway was isolated. Its function was authenticated by complementing a yeast coq5 mutant and by detecting increased cellular ubiquinone levels in the BoCOQ5-2-transformed bacteria. BoCOQ5-2 was found to promote Se volatilization in both bacteria and transgenic Arabidopsis (Arabidopsis thaliana) plants. Bacteria expressing BoCOQ5-2 produced an over 160-fold increase in volatile Se compounds when they were exposed to selenate. Consequently, the BoCOQ5-2-transformed bacteria had dramatically enhanced tolerance to selenate and a reduced level of Se accumulation. Transgenic Arabidopsis expressing BoCOQ5-2 volatilized three times more Se than the vector-only control plants when treated with selenite and exhibited an increased tolerance to Se. In addition, the BoCOQ5-2 transgenic plants suppressed the generation of reactive oxygen species induced by selenite. BoCOQ5-2 represents, to our knowledge, the first plant enzyme that is not known to be directly involved in sulfur/Se metabolism yet was found to mediate Se volatilization. This discovery opens up new prospects regarding our understanding of the complete metabolism of Se and may lead to ways to modify Se-accumulator plants with increased efficiency for phytoremediation of Se-contaminated environments.