bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Powdery Mildew of Tomato Caused by an Erysiphe sp. in Spain
Authors: Olalla L. , Torés J. A. 
Published: May 2007

A new powdery mildew disease of tomato (Lycopersicum esculentum Mill.) was observed for the first time in several greenhouses in Almería (Spain) in March through June 1997. Fungal growth appeared as typical, white, powdery mildew colonies that were restricted to upper leaf surfaces. Initially, individual colonies were small and nearly circular in shape but later enlarged and coalesced to cover the whole leaf surface. Conidia were produced singly on unbranched, 3-cell conidiophores, and were cylindrical to ovate, ranging in size from 27.6 to 43.5 μm (mean = 35.3, SD = 3.8) in length and from 14.1 to 23.2 μm (mean = 19.0, SD = 2.2, n = 95) in width. No fibrosin bodies were observed. Germ tubes were formed from the ends of conidia. Appressoria from mycelia were single and moderately lobed. Conidiophores measured from 56.6 to 108.8 μm (mean = 84.8, SD = 14.2) with straight foot cells 24.7 to 55.1 μm (mean = 38.6, SD = 7.5) in length, and from 7.3 to 10.2 μm (mean = 8.0, SD = 1) in width. Morphological characteristics of this powdery mildew are similar to those previously given for the Erysiphe sp. described in the United Kingdom (1) and Greece (2). Cleistothecia were not found, so species identification was not made. Conidia from infected tomato leaves were shaken onto leaves of melon (Cucumis melo L. ‘Rochet’), cucumber (Cucumis sativus L. ‘Bellpuig’), summer squash (Cucurbita pepo L. ‘Black Beauty’), watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai ‘Sugar Baby’) and tomato cvs. Roma, Daniela, and Marmande. After 7 days the disease was observed on summer squashes, melons, and all tomato cultivars, but not on watermelons or cucumbers. References: (1) J. T. Fletcher et al. Plant Pathol. 37:594, 1988. (2) D. J. Vakalounakis and A. Papadakis. Plant Pathol. 41:372, 1992.
First Report of Powdery Mildew Caused by an Oidium sp. on White Sweetclover in Kansas
Authors: Stuteville D. L. 
Published: May 2007

Powdery mildew was observed on plants of white sweetclover (Melilotus alba Medik.) in Riley County, Kansas, in 1995, 1996, and 1997 but was not examined closely until 1997. White, effuse to dense, amphigenous mycelia bearing Oidium conidia were obvious by mid June. Effuse growth occurred on petioles and stems. Invaded leaflets wilted and dropped, sometimes leaving a green petiole. Signs and symptoms diminished during the warmer periods of July and August, reoccurred in September, and remained prominent until the foliage froze in November. However, on 1 December, viable, newly produced conidia were collected from scant hyphal growth on protected leaves at the base of a few plants. A sexual state was not found. Characteristics of the conidial state fit those of Erysiphe pisi (1). Powdery mildew was never observed on plants of yellow sweetclover (M. officinalis (L.) Lam.) growing among the mildewed plants of white sweetclover. This is the first report of powdery mildew on M. alba in Kansas. Reference: (1) H. J. Boesewinkel. Bot. Rev. 46:167, 1980.
First Report of Powdery Mildew Caused by Sphaerotheca fusca on Tomatillo in California
Authors: Koike S. T. , Smith R. F. 
Published: May 2007

Tomatillo or husk tomato (Physalis ixocarpa Brot.) is an annual Solanaceous bush grown for its fruit, which are harvested when the fruit fill the enlarged calyx and are used primarily in Hispanic cooking. In the summer of 1997, commercial field-grown tomatillo in the Salinas Valley (Monterey County) was severely affected by a powdery mildew disease. Fungal growth was found on leaves, petioles, and calyces and resulted in twisting, desiccation, and premature senescence of the tissues. The mycelium was white to gray, ectophytic, amphigenous, and effuse. Mycelial appressoria were indistinct. Conidiophore foot cells were straight, cylindric, measured 36.1 to 61.1 µm (mean 47.0) × 11.1 to 13.9 µm (mean 11.7), and were followed by 1 to 3 shorter cells. Doliform conidia were formed in chains and measured 25.0 to 50.0 µm (mean 32.5) × 11.1 to 22.2 µm (mean 17.7). The length-to-width ratios of conidia generally were less than 2.0, and fibrosin bodies were present. Germ tubes usually were laterally inserted, lacked conspicuous appressoria, and were of the pannosa-type. Cleistothecia were not observed. Based on these characters, the fungus was identified as Sphaerotheca fusca (Fr.) Blumer, Beitr. Krypt.-Fl. Schweiz (1). Pathogenicity was confirmed by gently pressing infected leaves onto leaves of potted tomatillo. Inoculated plants were kept in a chamber at 100% humidity for 48 h, and then maintained in a greenhouse. Powdery mildew developed on inoculated plants after 12 to 14 days, while uninoculated plants did not develop disease. The experiment was conducted a second time and the results were the same. This is the first report of a powdery mildew disease of tomatillo in California. Reference: (1) U. Braun. Nova Hedwigia 89:1, 1987.
Severe Outbreak of Chocolate Spot of Fava Bean, Caused by Botrytis fabae, in California
Authors: Koike S. T. 
Published: May 2007

A damaging disease developed on commercial fava bean (Vicia faba L.) in coastal California following heavy rains in January through March, 1998. Two symptom types were observed. The most common symptoms on leaves and stems were small (1 to 5 mm), circular to oblong, dark red spots. As disease progressed, spots coalesced and caused large red areas on leaves and stems. Secondly, large (8 to 12 mm), oblong to irregular, dark brown necrotic spots with concentric circles formed on leaves, resulting in blighting and death of foliage. Severely affected plants lost over 50% of foliage and pod development was poor. Botrytis fabae was consistently isolated from both types of spots (1,2). Ellipsoidal to ovoid conidia measured 17 to 22 × 11 to 17 μm, and all isolates formed profuse, small (1 to 3 mm), spherical to oblong, black sclerotia. Pathogenicity was confirmed by inoculating isolates onto fava bean plants, incubating them in a humidity chamber for 48 h, then maintaining plants in a greenhouse. Inoculated plants developed both types of symptoms, and B. fabae was reisolated. Uninoculated controls developed no symptoms. The experiment was repeated and results were the same. While chocolate spot of fava bean has been observed previously in various parts of the state, this is the first documentation of this disease in California. The disease was also confirmed on fava bean grown as a winter cover crop in the same coastal area of California. References: (1) J. G. Harrison. Trans. Br. Mycol. Soc. 83:631, 1984. (2) J. G. Harrison. Plant Pathol. 37:168, 1988.
Identification of the East African Strain of Sweet Potato Chlorotic Stunt Virus as a Major Component of Sweet Potato Virus Disease in Southern Africa
Authors: Gibson R. W. , Kaitisha G. C. , Randrianaivoarivony J. M. , Vetten H. J. 
Published: May 2007

Sweet potato virus disease (SPVD) is the most damaging disease of sweet potato Ipomoea batatas (L.) Lam. in Africa. It is caused by sweet potato feathery mottle potyvirus (SPFMV) plus either the West African strain of sweet potato chlorotic stunt crinivirus (Closteroviridae) (SPCSV-WA) (2) or the serologically distinct and apparently more severe East African strain (SPCSV-EA) (1). Typical symptoms of SPVD include severe plant stunting, leaf distortion, chlorosis, mosaic, or vein clearing (1). During a survey done in February 1998 of 48 farmers' fields in Lusaka Province and North Western Province of Zambia, sweet potato plants with typical SPVD symptoms were observed. Incidence was generally 1 to 5% but occasionally >20%. To determine which viruses (SPFMV, SPCSV-EA, SPCSV-WA) were present in symptomatic plants, enzyme-linked immunosorbent assays (ELISAs) were done on leaf sap extracts. Twenty-two SPVD-affected plants from Lusaka Province and 15 from North Western Province were tested and SPFMV and SPCSV-EA (but not SPCSV-WA) were detected in all samples. SPCSV-EA by itself may cause purpling or yellowing of lower or middle leaves (1). Eight plants showing these symptoms were collected from North Western Province, and SPCSV-EA only was detected in six of the samples. SPVD was also observed in a 1997 survey of crops near Antsirable, Madagascar; incidence was generally <1% but occasionally >20%; SPFMV and SPCSV-EA, but not SPCSV-WA, were detected in two SPVD samples tested. Our results are the first report of SPCSV in southern Africa. SPVD in the regions surveyed appears to be due to SPFMV and SPCSV-EA; SPCSV-WA was not detected. References: (1) R. W. Gibson et al. Plant Pathol. 47:95, 1998. (2) G. A. Schaefers and E. R. Terry. Phytopathology 66:642, 1976.
First Report of Red Clover Vein Mosaic Carlavirus Naturally Infecting Lentil
Authors: Larsen R. C. , Myers J. R. 
Published: May 2007

Lentil (Lens culinaris Medik.) is an important legume crop grown in the dryland Pacific Northwest areas of eastern Washington and Oregon, and northern Idaho. Lentil is highly susceptible to pea enation mosaic enamovirus (PEMV) and bean leafroll luteovirus (BLRV), and infection may result in severe yield losses. Recently, lentil was also found to be infected experimentally with red clover vein mosaic carlavirus (RCVMV) (1). The virus is most commonly transmitted in the Pacific Northwest by the pea aphid (Acyrthosiphon pisum Harris) in a nonpersistent manner. In 1997, cv. Brewer lentil bait plants were planted at the Vegetable Research Farm at Oregon State University to monitor incidence of PEMV and BLRV. Many of the plants developed symptoms typical of PEMV. However, other plants exhibited severe stunting, proliferation of axillary branches, and general chlorosis or death. Bait plants were harvested in August, and 204 random samples were tested for PEMV, RCVMV, BLRV, alfalfa mosaic alfamovirus (AMV), and pea streak carlavirus (PeSV) by standard enzyme-linked immunosorbent assay (ELISA) protocols. Antiserum for RCVMV was made in the Prosser lab against an isolate from chickpea collected in Washington State (1). RCVMV was detected in 76 (34%) of the 204 samples. PEMV, AMV, BLRV, and PeSV were detected in 197 (89.5%), 23 (11.3%), 2 (0.9%), and 0 (0%) of samples, respectively. Results showed that 75/76 of the samples positive for RCVMV were also coinfected with PEMV. Plants infected with RCVMV in the greenhouse also produced mild systemic mosaic symptoms in selected hosts inoculated mechanically, including pea (Pisum sativum L.), chickpea (Cicer arietinum L.), faba bean (Vicia faba L.), and lentil. Lentil and chickpea also showed moderate to severe stunting. Chlorotic local lesions were formed on Chenopodium amaranticolor Coste & Reyn. and C. quinoa Willd. Oligonucleotide primers were designed with sequence data obtained from the Washington isolate of RCVMV (1), and identification of the virus was verified in pea and lentil by polymerase chain reaction (PCR). Primer design of RCV34V and RCV653C targeted a 619-bp fragment located in the viral coat protein gene. Plants testing positive by ELISA yielded PCR products of the expected size when visualized on agarose gels. This is the first report of natural infection of lentil by RCVMV. Reference: (1) R. C. Larsen et al. Phytopathology 87:S56, 1997.
Cucumber Mosaic Virus on Asiatic Hybrid Lilies in India
Authors: Ram Raja , Sharma Anupama , Singh R. K. , Chauhan Daizy , Zaidi A. A. 
Published: May 2007

Asiatic hybrid lilies are popular cut flowers with a range of bright colors. Of the several viruses reported from lily (2,3), cucumber mosaic virus (CMV) reduces flower quality and yield (1). Classical symptoms of CMV were observed in recently introduced plants of Asiatic hybrid lilies in Kangra Valley, Himachal Pradesh. The symptoms were mild leaf mosaic, ring spot, transient vein yellowing, occasionally with growth deformation, and flower breaking. Leaf samples from cvs. MonteNegro, Yellow Present, Apeldoorn, Toscana, Connecticut King, and Adelina were collected randomly on the basis of symptom expression. Viral-associated double-stranded RNA (dsRNA) analysis was used to analyze tissue from symptomatic and asymptomatic plants for evidence of a possible cucumovirus. dsRNA analysis resulted in a banding profile typical of that seen with cucumoviruses. There was no evidence of dsRNA in the asymptomatic tissue. Presence of CMV in the symptomatic plants was also confirmed by enzyme-linked immunosorbent assay with antiserum from Agdia (Elkhart, IN). Virus from symptomatic tissues was purified and 30 nm polyhedral, viruslike particles were observed that were subsequently tested for CMV with counter immunoelectrophoresis with antibodies of CMV-C and CMV-D (antibodies obtained from H. A. Scott, University of Arkansas) and ATCC CMV antisera PVAS 242-A. Our isolate differs from other prevalent CMV isolates of Kangra Valley, having a narrow host range and not being readily sap transmissible. However, this isolate is normally transmitted to progeny bulblets. Lack of fallow periods, continuous cropping of other CMV-susceptible bulbous crops, and occasional sprouting of uncollected lily bulblets enhance inoculum build-up. Planting of CMV-tested lilies is recommended to avoid disease losses and to reduce viral inoculum floriculture fields. This is the first report of CMV in Asiatic hybrid lilies in India. References: (1) M. P. Benettii and L. Tomassoli. Acta Hortic. 234:465, 1988. (2) P. Brierley. Phytopathology 30:250, 1940. (3) L. Tomassoli and M. P. Benettii. Adv. Hortic. Sci. 2:117, 1988.
A Serious Outbreak of Race 6 of Xanthomonas campestris pv. vesicatoria on Pepper in Southern Florida
Authors: Pernezny K. , Collins J. , Stall R. E. , Shuler K. , Datnoff L. E. 
Published: May 2007

In the 1997-1998 winter vegetable season, a widespread and serious outbreak of bacterial spot occurred on pepper in commercial fields throughout southern Florida. This was the first serious epidemic of bacterial spot on pepper in southern Florida since the 1993-1994 season. Cultivars affected included those with resistance to races 1–3 of X. campestris pv. vesicatoria, commonly found in previous Florida surveys (1). Field sampling designs, isolation methods, and pathogen identification were carried out as previously described (1). Twenty-seven fields were sampled in Palm Beach, St. Lucie, Martin, Broward, and Collier counties. The race of each strain was determined by infiltration of 3.0 × 108 CFU per ml of sterile tap water suspension into Early Calwonder and three near-isogenic lines of Early Calwonder with genes for vertical resistance to specific races of the pathogen. Test plants were maintained in the greenhouse and observed for hypersensitive and disease reactions over several days. Of a total of 244 X. campestris pv. vesicatoria strains collected, 73.4% were identified as race 6 and 10.2% as race 4. Irrespective of the presence of resistance genes in cultivars sampled, race 6 (eastern Florida) and race 4 (southwestern Florida) predominated in this study. Copper tolerance was widespread among X. campestris pv. vesicatoria strains of all races, with 91% of the strains showing tolerance to 250 g per ml of CuSO4 · 5H2O incorporated into 0.5% (wt/vol) glucose-nutrient agar. Selection pressure resulting from widespread planting of race 1, 2, 3-resistant cultivars may have contributed to this outbreak. High disease pressure also may be related to the unusually wet winter. Rainfall accumulation from December 1997 through March 1998 was 25.6 cm above normal. Reference: (1) K. Pohronezny et al. Plant Dis. 76:118, 1992.
First Report of Black Rot of Cauliflower and Kale Caused by Xanthomonas campestris pv. campestris in Yugoslavia
Authors: Obradović A. , Arsenijević M. 
Published: May 2007

In Yugoslavia, Xanthomonas campestris pv. campestris was isolated from forage kale in 1964 and cabbage in 1997 (1). Recently, the incidence and severity of black rot symptoms on cabbage, cauliflower, and kale have increased. Gram-negative, rod-shaped, motile bacteria were isolated from the diseased leaf and vascular tissues of cauliflower and kale plants collected from 1995 to 1998. The isolates formed yellow, convex, mucoid colonies on yeast dextrose chalk medium, metabolized glucose oxidatively, grew at 37°C, hydrolyzed gelatin and esculin, produced acids from d-arabinose, glucose, sucrose, and trehalose, and did not reduce nitrates. They were nonfluorescent, amylolytic and pectolytic, oxidase negative and catalase positive, and tolerant to 5% NaCl but not to 0.1% triphenyl tetrazolium chloride. Koch's postulates were completed by injecting bacterial suspensions (108 CFU/ml) into leaf petioles of cabbage, cauliflower, and kale seedlings (2- to 3-leaf stage). Dark green watersoaking of petioles and leaf veins followed by yellowing and collapse of inoculated plants was observed after 3 to 5 days. When compared with published information (2), the isolates were identified as X. campestris pv. campestris. This is the first occurrence of this bacterium in cauliflower and kale in Yugoslavia. References: (1) O. Jovanovic et al. Plant Prot. Belgrade 221:175, 1997. (2) N. W. Schaad. 1988. Laboratory Guide for Identification of Plant Pathogenic Bacteria. 2nd ed. The American Phytopathological Society, St. Paul, MN.
Leaf Blight of Endive and Escarole, Caused by Rhizoctonia solani, in California
Authors: Koike S. T. , Subbarao K. V. 
Published: May 2007

Endive (Cichorium endivia) and escarole (broad-leaf type of C. endivia) are two of the many leafy vegetables produced commercially in coastal California. For several years, both crops have been affected by a disease that causes soft, watery, brown leaf decay. In the tightly appressed heads of endive and escarole plants, decay generally spreads in a concentric circle, resulting in circular whorls of brown, rotted leaves within diseased heads. Such symptoms make the heads unmarketable. In the Salinas Valley (Monterey County), the disease was much more prevalent during 1998, when weather was affected by “El Niño.” Rhizoctonia solani was isolated consistently from symptomatic leaves of both endive and escarole. Pathogenicity was tested by placing two agar plugs of representative isolates inside the leaf whorls of 15 potted plants each of endive (cv. Tres Fine Maraicchere) and escarole (cv. Full Heart). Watery, brown leaf decay, similar to symptoms observed in the field, occurred on all plants within 7 days after inoculation, and R. solani was reisolated. Control plants, treated with sterile agar plugs, did not develop disease. Tests were repeated, and results were similar. Anastomosis-group testing revealed that four endive isolates belonged to AG2-2 (1). This appears to be the first report of leaf blight of endive and escarole caused by R. solani in California. Reference: (1) Sneh et al. 1991. Identification of Rhizoctonia Species. The American Phytopathological Society, St. Paul, MN.
First Report of a Bean-Infecting Begomovirus from Macroptilium lathyroides in Puerto Rico That Is Distinct from Bean Golden Mosaic Virus
Authors: Idris A. M. , Bird J. , Brown J. K. 
Published: May 2007

Bean golden mosaic begomovirus (BGMV) was long suspected to cause bright yellow mosaic symptoms in Macroptilium lathyroides (L.), a weed common to Puerto Rico. M. lathyroides plants exhibiting bright yellow mosaic symptoms were collected from Puerto Rico during 1994 to 1999, and the biotic and molecular characteristics of the suspect begomovirus were determined. Symptoms in M. lathyroides, indistinguishable from those observed in field-infected plants, were reproducible by whitefly transmission (Bemisia tabaci type B) and biolistic inoculation of leaf extracts (1). In bean, Phaseolus vulgaris (L.) ‘Topcrop,’ the M. lathyroides virus caused green-yellow mosaic foliar symptoms and stunting, reminiscent of symptoms caused by BGMV from Puerto Rico (BGMV-PR). However, biolistic- or whitefly-mediated inoculation of M. lathyroides with BGMV-PR resulted in no discernible infection. Sequence analysis (2) of the coat protein (CP) gene (AF176092) and common region of the A (CR-A) (AF176093) and B (CR-B) (AF176094) components of the virus from M. lathyroides indicated that these sequences shared only 77.3 to 79.3% and 62.4 to 68.8% identity, respectively, with BGMV from the Dominican Republic, Honduras, Guatemala, Jamaica (JAM), and PR. Alignment of the M. lathyroides virus CP sequence with other well-studied begomoviruses indicate its closest relative is BGMV-PR (82%) and that it shares less than 73% identity with partial CP sequences of Macroptilium golden mosaic virus-JAM (AF089839, AF089840). The directly repeated CR sequences of the M. lathyroides virus, putatively involved in AC1 binding, are TGGTGACTGGTG and are distinct from TGGAGACTGGAG, the analogous direct repeat in BGMV-PR. We provisionally designate the new, previously undescribed begomovirus species from M. lathyroides, Macroptilium mosaic virus (MaMV). Results indicate MaMV-PR and BGMV are distinct, bean-infecting begomoviruses from the Caribbean and that MaMV-PR may pose a new threat to bean production, particularly where the type B vector is established. References: (1) J. K. Brown and R. Ryan. Phytopathology 81:1217, 1991; (2) A. M. Idris and J. K. Brown. Phytopathology 88:648, 1998.