bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of the Root-Knot Nematode Meloidogyne marylandi on Turfgrasses in Israel
Authors: Oka Y. , Karssen G. , Mor M. 
Published: May 2007

In a turfgrass nursery in Arava, Israel, a population of root-knot nematodes was isolated from poorly growing Zoysiagrass (Zoysia japonica Steud.) with symptoms of foliar chlorosis and roots with very small, smooth galls and protruding egg masses. The isolated population (genus Meloidogyne) included females and second-stage juveniles, whereas no males were observed. Measurements and morphological observations of 20 second-stage juveniles (body length = 423 ± 13 μm, dorsal gland orifice from stylet base = 2.6 ± 0.4 μm, tail length = 63 ± 3 μm, hyaline tail length = 12.4 ± 0.9 μm and hemizonid posterior to excretory pore) and 10 adult females (stylet length = 12.5 ± 0.7 μm, dorsal gland orifice from stylet base = 3.3 ± 0.5 μm, excretory pore to head end = 11.9 ± 1.3 μm and perineal patterns rounded to ovoid with coarse striae) conformed to the description of Meloidogyne marylandi Jepson and Golden (3). Additionally, the identification was confirmed when females and second-stage juveniles were compared with available paratype slides. The isozymes malate dehydrogenase (EC 1.1.1.37) and esterase (EC 3.1.1.1) of young, adult females were also different from those of other described root-knot nematode species, including M. graminis, a taxon closely related to M. marylandi (4). M. marylandi was discovered and described from Bermudagrass (Cynodon dactylon (L.) Pers) in Maryland in 1987. Outside the United States, it has only been isolated from Zoysia matrella in Japan (1,2,3). In host range tests with different turfgrasses, stolons with roots were inoculated after 1 week with 500 second-stage juveniles per plant and 6 weeks later, the produced egg-masses where counted. These tests showed that this root-knot nematode isolate reproduced on Z. japonica and Pennisetum clandestinum, while no egg masses were observed on the roots of Dactyloctenium australe, Paspalum vaginatum, and Stenotaphrum secundatum. Additionally, some cereals grown from seeds were tested. Wheat (Triticum aestivum), barley (Hordeum vulgare), and bristle oat (Avena strigosa) were infested with this nematode, while oat (A. sativa) was not. Although the origin of this root-knot nematode in Israel is unknown, it could have been distributed throughout the country with commercial turfgrass. To our knowledge, this is the first report of M. marylandi in Israel and outside the United States and Japan. References: (1) M. Araki. Jpn. J. Nematol. 22:49, 1992. (2) A. M. Golden. J. Nematol. 21:453, 1989. (3) S. B. Jepson and A. M. Golden. Pages 263–265 in: Identification of Root-Knot Nematodes (Meloidogyne species). CAB International, Wallingford, U.K., 1987. (4) G. Karssen. The plant-parasitic nematode genus, Meloidogyne Göldi, 1892 (Tylenchida) in Europe. Brill, Leiden, the Netherlands, 2002.
First Report of Powdery Mildew Caused by Erysiphe cichoracearum on Creeping Thistle (Cirsium arvense) in North America
Authors: Newcombe G. , Nischwitz C. 
Published: May 2007

Creeping or Canada thistle (Cirsium arvense (L.) Scop.) is a perennial weed of Eurasian origin that arrived in North America as early as the 1700s (3). Spreading by seeds and rhizomes, it is now widely distributed in Canada, Alaska, and 40 other states. It is apparently absent from Texas, Oklahoma, Louisiana, Mississippi, Alabama, Georgia, Florida, and South Carolina (1). Powdery mildew is common on C. arvense in Europe, but it has never been observed in North America (4). In Europe and Asia, powdery mildew of C. arvense is caused by any one of the following fungi: Leveillula taurica, two species of Sphaerotheca, and varieties of Erysiphe cichoracearum and E. mayorii. Specimens of C. arvense infected with powdery mildew (deposited in the U.S. National Fungus Collections as BPI 843471) were collected in the fall of 2003 near Moscow, ID and in two areas in Oregon (the canyon of the Grande Ronde River and near the base of the Wallowa Mountains). Mycelium and cleistothecia were observed on stems and upper and lower surfaces of leaves. The mean diameter of the cleistothecia was 122 (±11.6) μm. Basally inserted, mycelioid appendages were hyaline or brown and varied considerably in length, but most were in the range of 80 to 120 μm. Asci averaged 58 (±5.5) μm × 35 (±4.1) μm in length and width, respectively. Each ascus bore two ascospores averaging 23 (±1.4) μm × 14 (±1.7) μm. Conidia averaged 30 (±3.0) μm × 14 (±0.8) μm. The specimens fit the description of E. cichoracearum DC. (2). Because the length/breadth ratio of conidia is greater than 2, the specimens could be further diagnosed as E. cichoracearum var. cichoracearum (2). Also noteworthy was the presence of the hyperparasitic Ampelomyces quisqualis Ces. ex Schlechtend. E. cichoracearum is thought to be a cosmopolitan powdery mildew of broad host range, but this concept is difficult to reconcile with the absence of mildew on North American populations of C. arvense for more than 200 years. References: (1) Anonymous. USDA Natural Resources Conservation Service Plants Profile for Cirsium arvense. On-line publication, 2003. (2) U. Braun. A monograph of the Erysiphales (powdery mildews), J. Cramer, Berlin-Stuttgart, 1987. (3) G. Cox. Alien Species in North America and Hawaii, Island Press, Washington, D.C., 1999. (4) D. F. Farr et al. Fungal Databases, Systematic Botany and Mycology Laboratory, ARS, USDA. On-line publication, 2003.
Occurrence of Arabis mosaic virus and Grapevine leaf roll associated virus-3 on Grapevines in Iran
Authors: Pourrahim R. , Ahoonmanesh A. , Farzadfar Sh. , Rakhshandehro F. , Golnaraghi A. R. 
Published: May 2007

During 2001, a survey was conducted in vineyards in northwestern Iran and the eastern and western provinces of Azarbaijan, Zanjan, and Qazvin to detect the presence of Arabis mosaic virus (ArMV) and Grapevine leaf roll associated virus-3 (GLRaV-3). From December 2001 through March 2002, 5,352 dormant stem cuttings were collected. A portion of all stem cuttings was callused, rooted, potted, and grown in a greenhouse. Each sample was tested for the presence of ArMV and GLRaV-3 with specific antisera (Bioreba, Basel, Switzerland). Extracts of bark scrapings were prepared from the remaining portion of the dormant cuttings. After bud break of rooted cuttings, leaf extracts were prepared by the method used by Rowhani et al. (2). Dormant bark and leaf extracts were used with double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Among the samples tested, ArMV and GLRaV-3 were found in 4.7 and 2.3% of the collection, respectively. Leaf extracts that had tested positive for ArMV using ELISA, were mechanically inoculated on the indicator host plants of Chenopodium amaranticolor, Cucumis sativus, and Petunia × hybrida. All plants developed local lesions that subsequently developed systemic chlorosis that is reported for ArMV. Biological assays confirmed the results of ArMV using ELISA. To confirm testing, a number of the samples that were found positive for GLRaV-3 in ELISA tests were tested by reverse transcription-polymerase chain reaction (RT-PCR) technique using previously described specific primers (1). The PCR reaction resulted in the specifically amplification of a 300-bp fragment of GLRaV-3 RNA. In cvs. White Keshmesh, Ghezel Ozum, Red Lal, Askari, and Red Kehsmesh, symptoms associated with GLRaV-3 were reduced growth with smaller leaves and shoots. By late summer, the leaves rolled downward and the interveinal areas of the leaves turned to red, while the principal veins remained green in cvs. Red Lal and Red Keshmesh. Symptoms associated with ArMV were reduced growth, shoots with short internodes, and leaf chlorosis and distortion. To our knowledge, this is the first report of ArMV and GLRaV-3 from grapevines in Iran. References: (1) A. Nassuth et al. J. Virol. Methods 90:37, 2000. (2) A. Rowhani et al. Plant Dis. 81:799, 1997.
First Report of Blueberry scorch virus in Cranberry in Canada and the United States
Authors: Wegener L. A. , Punja Z. K. , Martin R. R. 
Published: May 2007

Blueberry scorch disease, caused by the carlavirus Blueberry scorch virus(BlScV), is a serious disease of highbush blueberry (Vaccinium corymbosum L.) in North America and Europe. Symptoms of BlScV infection in highbush blueberry include necrosis of flower blossoms and young leaves, shoot blight, and chlorosis. In June 2003, BlScV was detected for the first time in cranberry (Vaccinium macrocarpon L.) in Abbotsford, British Columbia, Canada using double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Ten uprights were sampled from different locations in the bog, seven of which tested positive using DAS-ELISA. To confirm infection, total nucleic acid was extracted from infected cranberry leaf tissue according to an established protocol (2). Primers were developed against the published NJ-2 sequence of BlScV (GenBank Accession No. NC_003499). The forward primer, BS4586F (5′-CTTCAGGATGAGTGGTGCAA-3′), and the reverse primer, BS5164R (5′-CGCGTGCTGGAAGCATACAA-3′), were used in reverse-transcription polymerase chain reaction (RT-PCR) to amplify a portion of the RNA-dependent RNA polymerase gene of BlScV. The amplicons of the expected size were sequenced and the nucleotide sequence of the product showed 82% homology, and the predicted amino acid sequence had 91% homology with the published NJ-2 sequence. A random survey for BlScV in cranberry bogs in the Pacific Northwest Region of North America was conducted. Testing revealed the presence of BlScV in 7 of 42 bogs in British Columbia, Canada, 2 of 12 bogs in Oregon, and 3 of 18 bogs in Washington. Nucleotide sequencing of RT-PCR products of BlScV from a Washington bog showed 87 and 96% homology at the nucleotide and predicted amino acid level, respectively, in the methyltransferase of the NJ-2 strain using forward primer, BS276F (5′-CCGTCTGCAAGACATTAGAG-3′), and reverse primer, BS743R (5′-TCTTCTTCACCTCGTACTCG-3′). Several bogs had a high incidence of BlScV infection, with over 70% of the sampled uprights testing positive. Some infected cranberry bogs were adjacent to infected blueberry fields, while others were isolated. Transmission of the virus is likely to have occurred by aphids, which are known to be vectors of BlScV (1). Presently, BlScV appears to be asymptomatic in cranberry. To our knowledge, this is the first report of BlScV infecting cranberry. The potential for infection of other Vaccinium spp., such as lowbush blueberry (V. angustifolium Aiton), rabbiteye blueberry (V. ashei Reade), native Pacific Northwest species (V. membranaceum Douglas ex Torrey, V. ovatum Pursh, and V. parvifolium Smith), and ornamental Vaccinium spp. needs to be investigated. References: (1) P. R. Bristow et al. Phytopathology 90:474, 2000. (2) D. W. Hughes and G. Galau. Plant Mol. Biol. Rep. 6:253, 1988.
First Report of the Association of a Nanovirus with Foorkey Disease of Large Cardamom in India
Authors: Mandal B. , Mandal S. , Pun K. B. , Varma A. 
Published: May 2007

Large cardamom (Amomum subulatum Roxb.) is affected by the serious disease ‘foorkey’, which is of unknown etiology (1). Excessive sprouting and formation of bushy dwarf clumps at the base of mother plants that gradually die, characterize the disease. In surveys in the Sikkim-Darjeeling Hill area during 2002 and 2003, as much as 27% of plants were found to be affected. Electron microscopy of negatively stained, partially purified preparations from field-infected large cardamom plants showed the presence of isometric particles measuring 17 to 20 nm. The causal agent was successfully transmitted by the aphid Micromyzus kalimpongensis Basu, in a persistent manner. Ten randomly selected field samples gave A405 0.1 to 0.23 compared with 0.57 with positive control with enzyme-linked immunosorbent assay using antiserum to an Indian isolate of Banana bunchy top virus (BBTV). A fragment of approximately 850 bp was amplified from the diseased plants using polymerase chain reaction (PCR) with primers 5′-ATGGCGCGATATGTGGTATGC-3′ and 5′-TCAGCAAGAAAACCAACTTTATTC-3′, designed to amplify the putative Rep gene based on the sequences of DNA1 of BBTV. The PCR product was cloned and sequenced (GenBank Accession No. AY 485960) and showed 80 to 82% identity with the corresponding region of DNA1 of BBTV and 47.6 to 48.5% with other recognized nanoviruses. These findings indicate that a nanovirus is associated with ‘foorkey’ disease of large cardamom, which is tentatively named as Cardamom bushy dwarf virus. Reference: (1) P. M. Varma and S. P. Capoor. Indian J. Agric. Sci. 34:56, 1964.
Presence of Colletotrichum acutatum Causing Leaf Spot on Azalea japonica in Italy
Authors: Garibaldi A. , Bertetti D. , Vinnere O. , Gullino M. L. 
Published: May 2007

Rhododendron cultivation has a long history in northern Italy where a wide selection of varieties and hybrids are grown. In the fall of 2002, a previously unknown disease was observed on Azalea japonica cv. Palestrina in several commercial farms in the Province of Verbania. Leaves showed irregular necrotic areas that were 1 mm in diameter. Lesions were dark brown to black and were surrounded by a chlorotic halo. Eventually, lesions coalesced, forming large irregular spots. Heavily infected leaves fell prematurely, resulting in severe defoliation. On the infected leaves, acervuli were present from which cylindrical tapered conidia measuring 4.8 to 7.2 × 11.0 to 22.8 μm at one end were released. Fifty conidia per isolate were measured. Fungus identified as Colletotrichum acutatum was consistently recovered from infected leaves, disinfested in 1% NaOCl for 1 min, and plated on potato dextrose agar amended with 100 mg/l of streptomycin sulfate. Pathogenicity of three fungal isolates was confirmed by inoculating healthy A. japonica (cvs. Palestrina and Snow) plants grown in plastic pots (18-cm diameter, 3 liters). Plants (five per treatment) were sprayed with a conidial suspension (1 × 106 conidia per ml) of the three isolates of C. acutatum. Noninoculated plants served as a control. Inoculated and control plants were covered with plastic bags to maintain high relative humidity conditions. All plants were maintained in growth chambers at 20 ± 1°C (12 h per day of fluorescent light). Six days after the artificial inoculation, plants developed typical symptoms on the leaves. C. acutatum was consistently reisolated from infected plants. The pathogenicity test was carried out twice. Sequencing of the internal transcribed spacer region of the rDNA and a portion of the β-tubulin gene were performed, and the obtained sequences were compared with those available in GenBank. Identification of the fungus as C. acutatum, therefore was confirmed. To our knowledge, this is the first report of the presence of C. acutatum on A. japonica in Italy. Although observed presently only in a few nurseries, the disease has the potential to spread, becoming more relevant in an area where rhododendron cultivation is economically important. Anthracnose on rhododendron has already been described in several countries (1,2). References: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St Paul, MN, 1989. (2) O. Vinnere et al. Mycol. Res. 106:60, 2002.
First Report of the Root-Knot Nematode Meloidogyne javanica on Buchu (Agathosma betulina) in South Africa
Authors: Malan A. P. , Knoetze R. , Hugo H. J. 
Published: May 2007

Agathosma betulina, commonly known as buchu, has been used for centuries by the indigenous people of South Africa for medicinal purposes. Currently, the essential oils from buchu are used in medicine, food flavorings, and aromatic oils. Increased exploitation of natural growing buchu in the Fynbos biome and a worldwide shortage of buchu oil encouraged commercial cultivation in South Africa. The root-knot nematode (Meloidogyne spp.) is one of the most common plant-parasitic nematodes found on commercial crops grown in the Western Cape. It has also been isolated from the soil and roots of plants in the natural Fynbos vegetation (2). In June 2003, a nursery propagating buchu plants experienced problems with poor growth. Examination of the buchu roots under a stereo microscope showed extensive galling with large numbers of female root-knot nematodes with eggsacs. Nematode extractions of the soil were also done. Only second-stage juveniles of Meloidogyne spp. (311 per 250 ml of soil) were recovered. A polymerase chain reaction (PCR)-based diagnostic method (1) was used for the identification of the root-knot nematode species. Ten intact females were dissected from the roots and individually placed directly in 5 μl drops of 1× PCR reaction buffer (16 mM [NH4]2SO4, 67 mM tris-HCL, pH 8.8, 0.1% vol/vol Tween 20) ontaining 60 μg/ml of proteinase K. The tube was kept at -80°C for a minimum of 10 min. The tube was incubated at 60°C for 15 min and 5 min at 95°C. The PCR amplifications were then prepared directly in the same tube. Amplified DNA fragments were digested with HinfI and DraI. The digested DNA was loaded on a 2% agarose gel, separated by electrophoresis, and detected by ethidium bromide staining. The digested amplified DNA fragments correspond to those of Meloidogyne javanica. Morphological characteristics were used to verify the PCR-based identification of the nematode. To our knowledge, this is the first report of M. javanica causing extensive galling on the roots of Agathosma betulina. Visual damage to the roots indicates the root-knot nematode to be an important threat to the commercial cultivation of buchu. References: (1) R. Knoetze. Potential of the polymerase chain reaction for the identification of plant-parasitic nematodes. M.Sc. thesis. University of Stellenbosch, Stellenbosch, South Africa, 1999. (2) A. J. Meyer, S. Afr. J. Enol. Vitic., 20:75, 1999.
Barley Yellow Dwarf Disease in Natural Populations of Dominant Tallgrass Prairie Species in Kansas
Authors: Garrett K. A. , Dendy S. P. , Power A. G. , Blaisdell G. K. , Alexander H. M. , McCarron J. K. 
Published: May 2007

The grasses Sorghastrum nutans (Indian grass), Schizachyrium scoparium (little bluestem), Panicum virgatum (switchgrass), and Andropogon gerardii (big bluestem) are four of the most common plant species present in a tallgrass prairie (1). Infection with barley yellow dwarf virus (BYDV, family Luteoviridae) is of interest in these species because of the potential effects of the virus on tallgrass prairie plant communities and the potential for tallgrass prairie to function as a reservoir of the virus for infection in wheat or barley fields. In a previous inoculation experiment, an unidentified strain of BYDV transmitted by the aphid species Rhopalosiphum padi was reported to infect S. scoparium but none of the other three grass species (2). We sampled for the presence of five virus strains in at least 50 blooming plants of each grass species in a natural tallgrass prairie stand in August 2000. Samples were collected in watersheds that were designated 1B, 1D, K1A, 20B, and 20C at Konza Prairie Biological Station in the Flint Hills near Manhattan, KS. To detect the virus, we used enzyme-linked immunosorbent assay (ELISA) with antibodies purchased from Agdia (Elkhart, IN). For the PAV, MAV, RMV, and SGV strains, we used double-antibody sandwich ELISA with alkaline phosphatase label. For Cereal yellow dwarf virus (RPV), we used compound direct ELISA with alkaline phosphatase label. The scoring of ELISA results was based on comparison with infected and uninfected control plants of the same species. Symptoms of infection in the field were difficult to interpret visually, since plants in this natural environment often showed multiple symptoms of stress. None of the five strains were detected in 51 individuals of S. nutans. For 50 individuals of S. scoparium, the incidence of infection by the different strains was 4% for MAV, 0% for PAV, 2% for RMV, 0% for RPV, and 58% for SGV. For 51 individuals of P. virgatum, the incidence of infection was 31% for MAV, 0% for PAV, 0% for RMV, 0% for RPV, and 4% for SGV. For 64 individuals of A. gerardii, the incidence of infection was 59% for MAV, 0% for PAV, 0% for RMV, 0% for RPV, and 3% for SGV. The impact of BYDV on these tallgrass prairie species remains to be determined. The PAV strain is the most commonly reported strain in wheat in Kansas but was not recovered from these grass species. References: (1) C. C. Freeman. The flora of Konza Prairie: A historical review and contemporary patterns. Pages 69–80 in: Grassland Dynamics. A. K. Knapp et al., eds. Oxford, 1998. (2) W. N. Stoner. Plant Dis. Rep. 60:593, 1976.
First Report of Black Soft Rot of Indian Gooseberry Caused by Syncephalastrum racemosum
Authors: Garg Neelima , Prakash Om , Pandey B. K. , Singh B. P. , Pandey G. 
Published: May 2007

Indian gooseberry (Emblica officinalis Gaertn.) is a medicinal plant with high nutraceutical value. During November and December 2003, soft rot was noticed on harvested and stored (20 ± 5°C and 65 ± 5% relative humidity) fruits at the experimental farm in Rehmanhera, Lucknow, India (26°50′N, 80°54′E). These fruits had numerous, minute brown necrotic lesions showing white mycelial growth. A pronounced halo of water-soaked, faded tissue surrounded the lesion between the fringe of mycelium and healthy tissues. The rotted surface was covered with a black, powdery layer of spores. On Czapek yeast extract agar, fungal colonies were blackish grey, moderately dense, and covered the entire petri dish. The fungus produced aseptate mycelium. The sporangial heads were 30 to 50 μm in diameter with sporangiospores found linearly within cylindrical sacs (merosporangia) borne on spicules around the columella. Sporangiospores, spherical to cylindrical in shape and borne in chains, measured 3.0 to 5.0 μm long. The fungus was morphologically and physiologically identified as Syncephalastrum racemosum Schr. (2). For pathogenicity tests, healthy fruits (10 replicates) were surface sterilized and punctured inoculated aseptically with 1.0 × 106 conidia and incubated at 20 ± 5°C Typical symptoms of the disease appeared after 4 days. The fungus exhibited a strong level of cellulolytic activity as indicated by prolific growth on Indian gooseberry fiber waste under solid-state fermentation conditions. The level of cellulase activity (1) was 21 filter paper activity unit per ml at 72 hr in culture supernatant of basal medium having carboxymethyl cellulose as the carbon source. The fungus showed resistance to tannins (as much as 2%), since it could grow well in liquid growth medium (Czapek Dox broth) with 2% tannins and aonla juice with 1.8% tannins. Since Indian gooseberry is rich in fiber (2.5 to 3.4%) and tannins (1.5 to 2.0%), this may be an important pathogen. To our knowledge, this is the first report of the occurrence of Syncephalastrum racemosum on Indian gooseberry fruits. References: (1) T. K. Ghose. Pure Appl. Chem. 59(2):257, 1987. (2) J. I. Pitt and A. D. Hocking. Fungi and Food Spoilage. Academic Press. North Ryde, Australia, 1985.