bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Arceuthobium hondurense on Pinus tecunumannii
Authors: Mathiasen R. , Beatty J. , Melgar J. 
Published: May 2007

Honduran dwarf mistletoe (Arceuthobium hondurense Hawksw. & Wiens) is a rare dwarf mistletoe found only in Honduras (1,2). Thus far, it has been reported to parasitize only Pinus oocarpa Schiede (2). In October 1999, we observed infection by A. hondurense on P. tecunumannii (Schw.) Eguiluz et Perry along the trail to the summit of Montana del Celaque (elevation 1,750 to 1,800 m) on the east side of Celaque National Park, ≈5 km west of Gracias (Department Lempira), Honduras. Infected pines had witches′ brooms, and mistletoe shoot production was common on infected branches. This is the first report of A. hondurense on P. tecunumannii. Specimens of A. hondurense from P. tecunumannii were collected and have been deposited at the Herbario, Escuela Nacional de Ciencias Forestales, Siguatepeque, Honduras, and at the Deaver Herbarium, Northern Arizona University, Flagstaff. References: (1) F. G. Hawksworth and D. Wiens. 1996. Dwarf Mistletoes: Biology, Pathology, and Systematics. U.S. Dep. Agric. Agric. Handb. 709. (2) R. Mathiasen et al. Phytologia 36:211, 1998.
Natural Outbreak of a Bacterial Fruit Rot of Cantaloupe in Georgia Caused by Acidovorax avenae subsp. citrulli
Authors: Walcott R. R. , Langston D. B. , Sanders F. H. , Gitaitis R. D. , Flanders J. T. 
Published: May 2007

In April and July 1999, cantaloupe plants (Cucumis melo) from commercial greenhouses and fields in Grady, Colquitt, Mitchell, and Tift counties, GA, exhibited severe foliar necrosis and a fruit rot. Foliar symptoms were V-shaped, necrotic lesions occurring at the margin of the leaf and extending inward toward the midrib. Symptoms on the fruit surface were observed after net development and occurred randomly as round, necrotic, sunken spots or cracks a few millimeters in diameter. A soft rot originating from lesions on the surface of the fruit expanded into the flesh. Approximately 5% of the fruits were affected. Bacteria recovered from cantaloupe fruit and leaf tissues produced nonfluorescent, smooth, off-white colonies on King's medium B. Characteristic of Acidovorax avenae subsp. citrulli, the bacteria produced pits in carboxymethyl cellulose media (WFB 44), and reduced Tween 80 to give a visible precipitate on WFB 68 media (1). Based on fatty acid analysis, all strains were identified as A. avenae subsp. citrulli by Microbial Identification System software, version 3.6 (MIDI, Newark, DE), and similarity indices of 0.06, 0.79, 0.21, and 0.43 were recorded for strains recovered form Grady, Tift, Colquitt, and Mitchell counties, respectively. Using specific oligonucleotide primers (WFB 1/2) (2), PCR conducted on DNA from each strain yielded a 390-bp DNA fragment, confirming similarity to A. avenae subsp. citrulli. Indirect enzyme-linked immunosorbent assay with genus-specific antibodies also verified that the bacteria were Acidovorax spp. Pathogenicity of the A. avenae subsp. citrulli strains was confirmed by inoculating and observing symptom development on 2-week-old watermelon seedlings. Although all strains were identified and confirmed as A. avenae subsp. citrulli, restriction fragment length polymorphism data indicated that the Tift County strain was distinguishable from the others, suggesting that inoculum for these outbreaks may have originated from at least two different sources. References: (1) R. D. Gitaitis. 1993. Development of a seedborne assay for watermelon fruit botch. Pages 9–18 in: Proc. 1st Int. Seed Testing Assoc. Plant Dis. Commit., Ottawa, Canada. (2) R. R. Walcott and R. D. Gitaitis. (Abstr.) Phytopathology 88(suppl.):S92, 1998.
First Report of Botrytis Blight, Caused by Botrytis cinerea, on Hibiscus in South Africa
Authors: Swart L. , Langenhoven P. 
Published: May 2007

Roselle (Hibiscus sabdariffa L.) is an annual herb grown in China, Thailand, Mexico, and Africa. Different plant parts are used for cold and hot beverages, food ingredients, edible oil, and medicinal properties. In May 1999, a disease was observed in a commercial field of 6-month-old H. sabdariffa plants in Eshowe, KwaZulu-Natal, South Africa. Stems of diseased plants had brown, sunken lesions covered with green-gray spore masses. Infected stems collapsed. Lesions initiated on stems expanded rapidly under cool, humid conditions. In some cases, lesions developed on the flower stalk and expanded to the calyx, causing death of the calyx. Leaves had no lesions or sporulation, but as stem blight progressed, leaves wilted and fell off. Botrytis cinerea Pers.:Fr. (1) was consistently isolated from affected stem and flower stalk tissues. The pathogen produced profuse conidia and mycelia on the surface of dead and infected stems and calyxes, which resulted in a moldy gray appearance. The average size of conidia produced on naturally infected stems ranged from 5.5 to 8.0 × 6.0 to 13.0 μm (average 6.5 × 9.2 μm). On potato dextrose agar (1-month-old culture), conidia ranged from 5.0 to 9.5 × 6.5 to 12.5 μm (average 7.3 × 8.7 μm) based on 50 spore measurements. Microsclerotia were round or irregular and ranged from 1.2 to 3.0 × 1.0 to 2.5 mm (average 2.1 × 2.0 mm). Koch's postulates were confirmed by spraying potted, 6-month-old H. sabdariffa plants with a spore suspension (1 × 105 conidia per ml). Inoculated plants were enclosed in transparent plastic bags for 7 days at 15 and 20°C (night and day) in a glasshouse. Typical symptoms developed on stems and calyxes within 7 days after inoculation. B. cinerea was reisolated from affected tissues. Botrytis gray mold blight has been recorded on H. rosa-sinensis L. and Hibiscus sp. in Florida (2), but this is the first report of Botrytis blight on Hibiscus spp. in South Africa. Because the disease can result in plant death, Botrytis blight may have a significant impact on the establishment and yield of this crop in the field, especially under cool, wet growing conditions. References: (1) M. B. Ellis. 1971. Dematiaceous Hyphomycetes. CAB, Kew, Surrey, England. (2) D. F. Farr et al. 1989. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN.
First Report of Bacterial Spot of Lettuce Caused by Xanthomonas campestris pv. vitians in Turkey
Authors: Sahin F. 
Published: May 2007

During spring 1999, lettuce (Lactuca sativa) plants grown at Oltu in the eastern Anatolia region of Turkey were observed with numerous lesions typical of bacterial leaf spot. Lesions on leaves were irregular, small, pale green to black, water-soaked, and 2 to 5 mm in diameter. Coalescing lesions sometimes caused defoliation of older leaves. Isolations made from diseased leaves on yeast dextrose carbonate agar yielded nearly pure cultures of a yellow pigmented bacterium typical of a xanthomonad. Five bacterial strains were purified and used for further tests. The strains reacted positively with a Xanthomonas-specific monoclonal antibody, X1, in indirect enzyme-linked immunosorbent assays (1). Fatty acid analysis identified the strains as X. campestris pv. vitians (proposed name X. axonopodis pv. vitians), with greatest similarity indices of 29 to 71% (2). Pathogenicity of strains was confirmed on 5-week-old lettuce plants (cv. Darkland) sprayed with bacterial suspensions containing 108 CFU/ml of sterile water. Inoculated and sterile water-sprayed control plants were covered with polyethylene bags for 48 h at 25°C, after which bags were removed and plants were maintained in the greenhouse. Water-soaked spots similar to those in the field were observed on inoculated plants within 5 to 7 days. No symptoms developed on control plants. The bacterium was reisolated from inoculated plants and identified as X. campestris pv. vitians. This is the first report of bacterial leaf spot of lettuce in Turkey. References: (1) A. M. Alvarez et al. Phytopathology 84:1449, 1994. (2) Vauterin et al. Int. J. Syst. Bact. 45:472, 1995.
First Report of Verticillium Wilt of Sugar Beet, Caused by Verticillium dahliae, in Greece
Authors: Karadimos D. A. , Karaoglanidis G. S. , Klonari K. 
Published: May 2007

Wilting sugar beet plants (Beta vulgaris L.) were observed in fields in the Larissa area of central Greece during the summers of 1997 and 1998. Diseased plants, showing general yellowing and epinasty, were sporadically distributed in the fields. As symptoms progressed, the outer leaves wilted and became desiccated. Inner leaves showed marginal and interveinal yellowing. These areas later turned brown and became necrotic. Longitudinal sections of the roots of diseased plants displayed browning of vascular tissues. Fungal isolates obtained from discolored vascular tissues on potato dextrose agar (PDA) medium were identified as Verticillium dahliae based on morphological features (1). Cultures grew moderately fast on PDA at 23°C. Mycelia were hyaline and white to cream colored, becoming black with formation of microsclerotia. Conidiophores were hyaline and verticillately branched, with three to four phialides at each node. Conidia borne on phialides were ellipsoidal to short and cylindrical and mainly one-celled (2.5 to 8 × 1.4 to 3.2 µm). Microsclerotia began to form in 6- to 7-day-old cultures and were dark brown to black and varied in shape and size (25 × 50 to 100 µm diameter). Pathogenicity tests were carried out using the root-dip technique. Two-week-old seedlings (cv. Rizor) were inoculated by dipping roots in an aqueous suspension of 108 conidia per ml for 1 min. Inocula were obtained from 2-week-old cultures grown on PDA at 21°C by adding sterile water to the petri dish, gently shaking to detach conidia from the conidiophores, and filtering through a doublelayer of sterile cheesecloth. Roots of control plants were dipped in distilled water, and seedlings were transplanted to pots and placed in a growth chamber at 23°C with a 12-h photoperiod. Inoculated plants exhibited wilted leaves with interveinal yellowing ≈30 days after inoculation; symptoms were not observed on control plants. V. dahliae was reisolated from artificially inoculated plants. Measurements of yield parameters in healthy and diseased plants showed that the sugar content of diseased roots was significantly reduced, whereas root weight was not affected. Such results agree with a previous report on the effects of the disease on yield parameters (2). However, the disease is of minor importance in Greece mainly because of the low number of infected plants in the fields. This is the first report of Verticillium wilt of sugar beet in Greece. References: (1) Anonymous. 1971. Verticillium dahliae. No 256: Descriptions of Plant Pathogenic Fungi and Bacteria. Common w. Mycol. Inst., Kew, England. (2) J. O. Gaskill and W. A. Krentzer. Phytopathology 30:769, 1940.
First Report of Cucurbit yellow stunting disorder virus in Morocco
Authors: Desbiez C. , Lecoq H. , Aboulama S. , Peterschmitt M. 
Published: May 2007

In October, 1999, severe yellowing symptoms were observed in a melon (Cucumis melo L.) crop grown under plastic tunnels in the region of Agadir, Morocco. Large populations of whiteflies (Bemisia tabaci) were noticed during the early stages of the crop. At harvest, leaf samples were collected from two symptomatic plants and one symptomless plant. A mature yellow leaf was assayed from each symptomatic plant and for one of these two plants a younger leaf exhibiting only yellow spots. Cucurbit aphid-borne yellows virus, which causes similar symptoms in melons, was not detected by double-antibody sandwich enzyme-linked immunosorbent assay tests. Total RNA was extracted from fresh leaf tissues and submitted to reverse transcription and polymerase chain reaction with primers specific to two whitefly-transmissible viruses: Beet pseudo-yellows virus (BPYV) and Cucurbit yellow stunting disorder virus (CYSDV) (2). No amplification was obtained with BPYV-specific primers. In contrast, an expected 465-bp product was amplified in all samples from symptomatic plants with CYSDV-specific primers. No amplification was detected in samples from the symptomless plant nor from healthy control plants. B. tabaci-transmitted CYSDV has been reported in the Middle East, southwestern Europe, and North America (1,4). This is the first report of CYSDV in Morocco, and it follows the first report of another B. tabaci-transmitted virus, Tomato yellow leaf curl virus, in tomato (3), suggesting an important change in the viral pathosystem affecting vegetable crops in Morocco. References: (1) Kao et al. Plant Dis. 84:101, 2000. (2) Livieratos et al. Plant Pathol. 47:362, 1998. (3) Peterschmitt et al. Plant Dis. 83:1074, 1999. (4) Wisler et al. Plant Dis. 82:270, 1998.
First Report of Rhizoctonia solani AG-3 on Potato in Catalonia (NE Spain)
Authors: El Bakali M. A. , Martín M. P. , García F. F. , Montón R. C. , Moret B. A. , Nadal P. M. 
Published: May 2007

During the last 3 years, potatoes (Solanum tuberosum L.) with symptoms typical of Rhizoctonia canker and black scurf have been found in Catalonia; from 21,546 samples submitted to the official diagnostic laboratory (Laboratori de Sanitat Vegetal, DARP, Generalitat de Catalunya), 20% were infected with R. solani. Also, basidia and basidiospores of Thanatephorus cucumeris (A.B. Frank) Donk, the teleomorph of R. solani, have been observed frequently on stems near the soil surface. Previous work (1) has reported R. solani in the same geographic area, but anastomosis groups (AG) were not identified. Isolates (103) were collected from damaged roots, mature or progeny tubers, soil, debris, and weeds (roots and stem of Oxalis latifolia, Diplotaxis eurocoides, Solanum nigrum, Sorghum halepense, and Chenopodium album) in fields where potatoes were cultivated. All isolates were multinucleate, variable in number of nuclei (mean = 12, range = 7 to 19), and with morphological features typical of R. solani (3). Following the procedure of Parmeter et al. (2), all isolates (84) were identified as R. solani AG-3. Thirty-two isolates were evaluated for pathogenicity on potato plants at 20 to 25°C in the greenhouse. Germinated tubers (sprout length 3 cm) free of Rhizoctonia were placed in pea-sand mix (3:1, vol/vol; Compo Sana Universal, Barcelona, Spain) at 5-cm depth and inoculated by placing a 5-mm-diameter plug cut from 1-week-old cultures of each isolate adjacent to the sprouts. Potatoes were harvested 20 days after planting, and both emerged and nonemerged sprouts were examined for lesions and rated using a 0 to 4 scale. The AG-3 isolates caused major damage to roots and shoots (average disease rating 3.4). R. solani isolates were recovered from diseased plants and identified as AG-3. Preliminary field studies in Catalonia (Baix Llobregat and Maresme, unpublished) indicate that disease severity is not dependent on cultivar or related to yield reduction (10 to 65%), but is related to soil and seed contamination with sclerotia and mycelium. This is the first reported occurrence of R. solani AG-3 on potato in Catalonia. References: (1) Cebolla et al. Actas del III Congreso de la SECH, 1989. (2) Parmeter et al. Phytopathology 59:1270, 1969. (3) Sneh et al. Identification of Rhitzoctonia species. American Phytopathological Society, St. Paul, MN, 1991.
Fusarium nygamai Associated with Fusarium Foot Rot of Rice in Sardinia
Authors: Balmas V. , Corda P. , Marcello A. , Bottalico A. 
Published: May 2007

Fusarium nygamai Burgess & Trimboli was first described in 1986 in Australia (1) and subsequently reported in Africa, China, Malaysia, Thailand, Puerto Rico, and the United States. F. nygamai has been reported on sorghum, millet, bean, cotton, and in soil where it exists as a colonizer of living plants or plant debris. F. nygamai was also reported as a pathogen of the witch-weed Striga hermonthica (Del.) Benth. To our knowledge, no reports are available on its pathogenicity on crops of economic importance. In a survey of species of Fusarium causing seedling blight and foot rot of rice (Oryza sativa L.) carried out in Sardinia (Oristano, S. Lucia), F. nygamai was isolated in association with other Fusarium species—F. moniliforme, F. proliferatum, F. oxysporum, F. solani, F. compactum, and F. equiseti. Infected seedlings exhibited a reddish brown cortical discoloration, which was more intense in older plants. The identification of F. nygamai was based on monoconidial cultures grown on carnation leaf-piece agar (CLA) (2). The shape of macroconidia, the formation of microconidia in short chains and false heads, and the presence of chlamydospores were used as the criteria for identification. Two pathogenicity tests comparing one isolate of F. nygamai with one isolate of F. moniliforme were conducted on rice cv. Arborio sown in artificially infested soil in a greenhouse at 22 to 25°C. The inoculum was prepared by growing both Fusarium species in cornmeal sand (1:30 wt/wt) at 25°C for 3 weeks. This inoculum was added to soil at 20 g per 500 ml of soil. Pre- and post-emergence damping-off was assessed. Both F. nygamai and F. moniliforme reduced the emergence of seedlings (33 to 59% and 25 to 50%, respectively, compared to uninoculated control). After 25 days, the seedlings in infested soil exhibited a browning of the basal leaf sheaths, which progressed to a leaf and stem necrosis. Foot rot symptoms caused by F. nygamai and F. moniliforme were similar, but seedlings infected by F. nygamai exhibited a more intense browning on the stem base and a significant reduction of plant height at the end of the experiment. Either F. nygamai or F. moniliforme were consistently isolated from symptomatic tissue from the respective treatments. References: (1) L. W. Burgess and D. Trimboli. Mycologia 78:223,1986. (2) N. L. Fisher et al. Phytopathology 72:151,1982.
First Report of a Bulb Decay of Onion by Enterobacter cloacae in Colorado
Authors: Schwartz H. F. , Otto K. 
Published: May 2007

Sweet Spanish onion cultivars (Allium cepa L.) in northern Colorado displayed symptoms of postharvest bulb rot during September to November of 1999. This disease appears identical to that reported from infected onions in California in 1988 and is presumably associated with high temperature stress (1). Mature, firm bulbs harvested from scattered fields in Weld County exhibited a brownish discoloration and breakdown of inner scales. Gram negative, rod-shaped, cream-colored bacteria were consistently recovered from infected bulb tissue on nutrient agar. Physiological tests showed that the bacteria utilized glucose in an oxidative and fermentative manner and were catalase positive and oxidase negative. A representative strain was identified by Microbe Inotech Laboratories (St. Louis, MO) as Enterobacter cloacae (Jordan) Hormaeche & Edwards (2) using Biolog analysis, with a similarity index of 0.81. To confirm pathogenicity, a 0.5- to 1.0-ml suspension of bacteria (108 CFU/ml sdw) was injected into firm onion bulbs (7.5 to 10.0 cm diameter). After incubation for 14 days at 22°C in closed plastic bags in the dark, bulbs were cut in half and evaluated. Tan to brown discoloration and initial dry rot, similar to that observed postharvest, was observed in inoculated bulbs. The pathogen was reisolated from six of eight bulbs inoculated with the representative strain. No discoloration or disease developed on eight control bulbs injected with water. To our knowledge, this is the first report of E. cloacae from onion grown in Colorado. References: (1) A. L. Bishop and R. M. Davis. Plant Dis. 74:692, 1990. (2) Hormaeche and Edwards. Int. J. System. Bacteriol. 30:293, 1960.
Widespread Occurrence of Cotton leaf curl virus on Radish in Pakistan
Authors: Mansoor S. , Mukhtar S. , Hussain M. , Amin I. , Zafar Y. , Malik K. A. , Markham P. G. 
Published: May 2007

The current epidemic of cotton leaf curl disease (CLCuD) in Pakistan started in 1988 with the natural host range limited to a few plant species in the family Malvaceae. However, we have observed expansion in the host range of the virus, and several non-Malvaceous plants were found to be infected with the virus. Characteristic symptoms of CLCuD such as leaf curl and enations have been observed on radish plants, primarily in kitchen gardens. However, in 1999, levels of infection of 10 to 90% were observed both in commercial fields and kitchen gardens in the Punjab province of Pakistan. Both symptomatic and nonsymptomatic samples were collected from five different locations. Total DNA was isolated, dot-blotted on nylon membrane, and a full-length clone corresponding to DNA A of cotton leaf curl virus was labeled with 32P dCTP and used as a probe for the detection of a begomovirus. Strong signals were observed in symptomatic plants while no signals were observed in nonsymptomatic plants. Infection with a begomovirus was further confirmed by polymerase chain reaction (PCR) using degenerate primers for DNA A (1). Primers specific for the two distinct begomoviruses associated with CLCuD were also used in PCR reactions (2), and products of the expected size were obtained from all symptomatic samples, confirming infection with begomoviruses similar to those associated with CLCuD. A full-length probe of a nanovirus-like molecule associated with cotton leaf disease (3), called DNA 1 was labeled with 32P dCTP and detected the virus only in symptomatic plants. Similarly, primers specific for DNA 1 (3) amplified a product of expected size when used in PCR. On the basis of symptomatology and the detection of specific viral components associated with the disease, we confirmed that radish plants are infected with Cotton leaf curl virus (CLCuV). Since radish is a short duration crop, infection of CLCuV in radish may not serve as a direct source of infection for the next cotton crop. However, it is a potential threat to tomato crops which overlap with radish in the Punjab province. The detection of CLCuD in radish is another example of the mobilization of begomoviruses to previously unknown hosts. References: (1) M. R. Rojas et al. Plant Dis. 77:340, 1993. (2) S. Mansoor et al. Pak. J. Bot. 31:115, 1999. (3) Mansoor et al. Virology 259:190, 1999.