bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Lentil Ascochyta Blight Caused by Ascochyta lentis in Italy
Authors: Cappelli C. , Buonaurio R. , Torricelli R. 
Published: May 2007

In May 1997, ascochyta blight incited by Ascochyta lentis Vassiljevsky was observed at an incidence of less than 5% in lentil (Lens culinaris Medik.) fields in Umbria (Central Italy). Symptoms appeared on leaves and stems as tan spots surrounded by a dark margin. Small black pycnidia that produced a pink exudate containing hyaline, 1 septate, 14.2 to 15.8 × 3.5 μm conidia under high humidity were visible in the center of the spots. The fungus was consistently isolated on potato dextrose agar from diseased leaves or stems. To satisfy Koch's postulates, a conidial suspension (106 conidia per ml) of the fungus was sprayed on leaves of 20-day-old lentil plants (landrace Castelluccio) that were maintained in a humidity chamber for 96 h after inoculation. Lesions resembling symptoms that occurred in the field were observed on plants 3 weeks after inoculation. Symptoms were not observed on control plants sprayed with water. The fungus reisolated from the diseased plants was identical to the original isolates. Based on morphological characteristics of pycnidia and conidia as well as pathogenicity, the fungus was identified as A. lentis. A deep-freeze blotter method (2) was used to detect A. lentis in lentil seeds of 20 local landraces used by Umbrian farmers and two accessions from Canada and Turkey, as well as in seed collected from infected fields. The fungus was present only in the two lentil accessions with an incidence of about 5%. Although the fungus had been isolated from Italian seed germplasm in 1986 (1), this is the first report of ascochyta blight occurring in lentil crops in Italy. The heavy rainfalls that characterize the first stage of lentil cultivation in Umbria are favorable for disease development while hot and dry conditions that usually occur during flowering and maturation prevent the dissemination of inoculum and the infection of the seeds. For these reasons, some Umbrian areas could be more suitable for production of ascochyta-free lentil seeds. References: (1) W. J. Kaiser and R. M. Hannan. Phytopathology 76:355, 1986. (2) T. Limonard. Proc. Int. Seed Test. Assoc. 33:343, 1968.
First Report of Colletotrichum gloeosporioides as a Foliar and Die-back Pathogen of Prunus africana in Kenya
Authors: Mwanza E. J. M. , Waithaka S. K. , Mibey R. K. , Kariuki G. , Simons S. A. 
Published: May 2007

During tree disease surveys between February 1996 and March 1998 in highland forests of Kenya, leaves of Prunus africana (Hook f.) Kalkman collected from regeneration wildings in natural forests and seedlings raised in nurseries were found to be consistently heavily infected with a leaf spot and shot-hole disease caused by Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. in Penz., anamorph of Glomerella cingulata (Stoneman) Spauld. & H. Schrenk. The pathogen was identified by sectioning sub-epidermal acervuli on the leaf and also by plating infected tissue segments on 2% malt extract agar. The cultural and conidial morphologies were characteristic of C. gloeosporioides. The isolate is maintained at Kenya Forestry Research Institute (KEFRI) culture collection (No. 069-63) and identity ascertained by the International Mycological Institute (IMI) (ref. W5794). To confirm pathogenicity, leaves of 3-month-old seedlings of P. africana were sprayed to run-off with a conidial suspension adjusted to 105 conidia per ml or sterile water as a control. Following inoculation, the seedlings were covered with transparent plastic bags for 48 h and kept in a glasshouse at 23 ± 3°C under natural light conditions and relative humidity of 80%. Leafspot symptoms similar to those found on leaves of wildings in natural forests and nursery seedlings were evident on the inoculated leaves within 3 weeks. Five weeks later the necrotic spots on the leaves measured 2 to 6 mm in diameter. The spots were circular or irregular usually surrounded by a zone paler than the healthy tissue. Later the centers of the spots fell, leaving clean shotholes. C. gloeosporioides was consistently reisolated from all inoculated plants. When infection was severe, the pathogen caused premature leaf fall and die-back of the leader shoot. P. africana, formerly known as Pygeum africanum, is a widespread tree species in moist tropical Africa and produces durable timber; extracts from its bark are used for the treatment of prostrate gland disorders. This is the first report of which we are aware of C. gloeosporioides emerging as an important pathogen of P. africana. Reference: (1) M. H. Tsingalia. Afr. J. Ecol. 27: 207, 1989.
A Cowpea Seed Rot Disease Caused by Fusarium equiseti Identified in Nigeria
Authors: Aigbe S. O. , Fawole B. , Berner D. K. 
Published: May 2007

Fusarium equiseti (Corda) Sacc., reported on cowpea (Vigna unguiculata (L.) Walp.) seeds in India (2), was isolated for the first time in Nigeria from naturally infected cowpea seeds. Cowpea, cv. IT90K-76, seeds (400) from plants grown in Nigeria were surface-disinfested in 0.05% NaOCl and placed on moist filter paper in petri dishes (10 seeds per dish) and then in a dark incubator for 4 days at 27°C. After incubation, some seeds had fungal mycelia growing on their surfaces. When cultured on potato dextrose (PDA) and Spezieller Nährstoffarmer (SNA) agars, the fungi produced macroconidia characteristic of F. equiseti (1). Septate macroconidia were three to six celled with extended apical and distinctive foot-shaped basal cells. F. equiseti was recovered from 4.25% of seeds, and incidence correlated positively with development of seed rot symptoms. To confirm pathogenicity, 80 cowpea seeds were surface-disinfested with NaOCl, and 40 were soaked for 6 h in a suspension of 3 × 105 conidia of F. equiseti per ml of water. The remaining seeds were soaked in sterile distilled water. After incubation, white mycelia developed on 87.5% of seeds soaked in the conidial suspension and rotted without germinating. Only 5% of seeds soaked in sterile water developed seed rot symptoms. When cultured on PDA and SNA, fungi isolated from artificially infested seeds with rot symptoms again were identified as F. equiseti. References: (1) P. E. Nelson et al. 1983. Fusarium species: An illustrated Manual for Identification. Pennsylvania University Press, University Park. (2) O. K. Sinha and M. N. Khare. Seed Sci. Technol. 5:721, 1977.
First Report of Acidovorax avenae subsp. citrulli as a Pathogen of Cucumber
Authors: Martin H. L. , O'Brien R. G. , Abbott D. V. 
Published: May 2007

In March 1999, a foliar bacterial disease was observed in a commercial crop of cucumber (Cucumis sativus L.) cv. Jetset in Gumlu in northern Queensland, Australia. Initial symptoms consisted of angular, chlorotic, water-soaked lesions that later dried to necrotic areas of light brown, dead tissue. White bacterial ooze was commonly found on the undersides of young water-soaked lesions. Lesions were delimited by veins and distributed uniformly over leaf surfaces, and more than 20% of the crop was affected. No symptoms were observed on plant stems or fruits. Bacterial streaming from the edges of freshly cut young lesions was clearly visible in a droplet of water under ×100 magnification in the laboratory. Isolations were made from young lesions on King's medium B (1). A slow-growing, white, gram-negative, nonfluorescent bacterium was consistently isolated. Three isolates of the bacterium were identified, using the Biolog software program (Biolog, Hayward CA), and in each instance, the bacterium was confirmed as Acidovorax avenae subsp. citrulli, with a similarity of >0.80. Koch's postulates were completed with 8-day-old glasshouse-grown cucumber (cv. Jetset) seedlings. Seedlings were misted until runoff with a bacterial suspension of 3 × 108 CFU/ml and enclosed in plastic bags for ≈30 h at 22°C. Water-soaked lesions were observed on cucumber cotyledons 4 days after inoculation. This is the first report of A. avenae subsp. citrulli as a pathogen of cucumber. Reference: (1) E. O. King et al. J. Lab. Clin. Med. 44:301, 1954.
First Report on Natural Occurrence of Tomato Spotted Wilt Tospovirus in Basil (Ocimum basilicum)
Authors: Holcomb G. E. , Valverde R. A. , Sim J. , Nuss J. 
Published: May 2007

Virus-like symptoms were observed on basil plants (Ocimum basilicum L. ‘Mrs. Burns Lemon’ [MBL]) growing in containers and a demonstration plot at the Louisiana State University Burden Research Plantation, Baton Rouge, during July 1998. Symptoms consisted of ring spots, leaf distortion, and severe mosaic. Mechanical transmission of the suspect virus by sap inoculation from infected MBL to basil cvs. MBL, Aussie Sweet, Cinnamon, Siam Queen, and Sweet Dani was successful. Symptoms were similar to those on infected MBL. Nicotiana benthamiana Domin. reacted with local chlorotic spots followed by severe yellows, necrosis, and death. Electron microscopy of thin sections of infected basil revealed virus inclusions but no virus particles. However, infected N. benthamiana revealed the presence of 82-nm membrane-bound particles in the cytoplasm. The virus was identified from basil and N. benthamiana as the common strain of tomato spotted wilt tospovirus (TSWV) by enzyme-linked immunosorbent assay (Agdia, Elkhart, IN). An outbreak of thrips insects during the summer drought in 1998 was probably responsible for the occurrence of TSWV in basil. This is the first report of the occurrence of TSWV in basil (1). Reference: (1) A. A. Brunt et al., eds. 1996. Plant Viruses Online: Descriptions and Lists from the VIDE Database. Published online by Australian National University, Canberra.
First Report of Fusarium oxysporum f. sp. lycopersici Race 2 on Tomato in Italy
Authors: Stravato V. M. , Buonaurio R. , Cappelli C. 
Published: May 2007

During the summer of 1997, symptoms of Fusarium wilt were observed on tomato (Lycopersicon esculentum Mill.) cvs. Monica F1 and PS 110, which bear the I gene for resistance to race 1 of Fusarium oxysporum Schlechtend.:Fr. f. sp. lycopersici (Sacc.) W.C. Snyder & H.N. Hans., in two commercial production greenhouses in Latium (Fondi) and one greenhouse in Sardinia (Oristano). Infected plants showed yellowing, stunting, vascular discoloration, and premature death. A fungus from tomato stems with discolored vascular tissue was consistently isolated on potato dextrose agar (PDA) and, based on morphological features, was identified as F. oxysporum. To verify the pathogenicity of four fungal isolates, cv. Bonny Best tomato plants, which do not carry genes for Fusarium wilt resistance, were inoculated by dipping roots of 2-week-old seedlings in a suspension of 105 microconidia per ml for 30 s. Inocula were obtained from 1-week-old fungal cultures grown on PDA. Roots of control plants were dipped in water. Seedlings were transplanted to pots containing peat and river sand (1:1, vol/vol) and placed in a greenhouse at 20 to 25°C. One month after inoculation, all fungal isolates provoked wilting of inoculated plants. No symptoms were observed on control plants. The morphological features of the fungus reisolated from diseased plants were similar to those of the original isolates. Based on the pathogenicity test, we concluded that the fungal isolates belong to F. oxysporum f. sp. lycopersici. To determine the races of the fungal isolates, differential tomato lines VFN8 (I gene for resistance to race 1), Florida MH-1 (I and I2 genes for resistance to races 1 and 2), and I3R (I, I2, and I3 genes for resistance to races 1, 2, and 3) were inoculated with the four fungal isolates, using the same procedure described for the pathogenicity test. Because disease symptoms were detected on VFN8 but not on Florida MH-1 and I3R, we deduced that the fungal isolates belong to F. oxysporum race 2. This is the first report of F. oxysporum f. sp. lycopersici race 2 in Italy. Previous research indicated that race 1 is present in Italy (1). Currently, many commercially acceptable cultivars resistant to races 1 and 2 are available to Italian greenhouse growers. Reference: (1) M. Cirulli. Phytopathol. Mediterr. 4:63, 1965.
First Report of Potato Spindle Tuber Viroid in Costa Rica
Authors: Badilla R. , Hammond R. , Rivera C. 
Published: May 2007

During 1997 to 1998, symptoms of leaf roll, dwarfism, chlorosis, and occasional leaf necrosis were observed on Solanum tuberosum in several plots in Cartago, the principal potato-production region of Costa Rica. Because of the known association between potato leafroll virus (PLRV) and viroids (1) and previous reports of PLRV in Costa Rica, the presence of potato spindle tuber viroid (PSTVd) was suspected. Leaf samples from 122 symptomatic potato plants, cvs. Atzimba, Floresta, Idiafrit, and Birris, were collected from 10 plots. Total nucleic acids (TNAs) were extracted and purified (2) from collected symptomatic samples and six healthy potato controls. TNAs were spotted on nylon membranes and hybridized to a digoxigenin-labeled DNA probe specific for PSTVd. Of 122 symptomatic plants, 71 were positive for PSTVd based on dot blot hybridization. TNAs from 12 positive potato samples, including at least 1 sample from each cultivar, were used to inoculate Lycopersicum esculentum cv. Super Marmande. Eleven of twelve inoculated tomato plants showed symptoms of dwarfism, leaf deformation, and grayish foliage, often with a dull surface. TNAs were extracted from inoculated tomato and hybridized to the PSTVd probe. All inoculated symptomatic plants were positive for PSTVd based on dot blot hybridization. This is the first report of PSTVd in Costa Rica. References: (1) M. Querci et al. J. Gen. Virol. 78:1207, 1997. (2) W. Villalobos et al. Rev. Biol. Trop. 45:983, 1997.
First Report of Tomato Yellow Leaf Curl Geminivirus in Morocco
Authors: Peterschmitt M. , Granier M. , Aboulama S. 
Published: May 2007

In July 1998, shortened internodes, reduced leaf size, leaf curling, and bushy plants were observed in tomato crops in the coastal region near Casablanca, Morocco. The symptoms were similar to those described for tomato yellow leaf curl virus (TYLCV) disease. During September, the disease was present in more than 130 ha of outdoor and protected crops. Economic losses ranged between 20 and 100%. Similar symptoms were observed in tomato crops in the northeastern region of Morocco. During the same period, high populations of Bemisia tabaci (Gennadius) were observed on tomato, sweet pepper, and several weeds, including Sonchus oleraceus L., Chenopodium sp., Malva parviflora L., and Datura stramonium L. Attempts to control whiteflies with insecticides generally were unsuccessful. Using a pair of degenerate primers (3) that are expected to amplify a region of the A component of begomoviruses between the intergenic conserved nonanucleotide sequence and the first 5′ quarter of the capsid protein gene, an expected size product of 500 bp was obtained from six tomato leaf samples collected near Casablanca: four were obtained from symptomatic plants and two from apparently symptomless plants. A product of the same size was obtained from a sample of tomato infected with a TYLCV isolate from Reunion Island, France (2), but not from a sample from symptomless tomato plants from Reunion. The polymerase chain reaction (PCR) product obtained from one symptomatic sample from Morocco was cloned and sequenced (2). The resulting sequence (EMBL no. AJ133491) was at least 95.2% identical to sequences of TYLCV isolates from the Dominican Republic (EMBL no. AF024715), Cuba (EMBL no. AJ223505), Israel (EMBL no. X15656; EMBL no. X76319 for the mild clone), Spain (EMBL no. AF071228), and Reunion (EMBL no. AJ010790). Based on sequence comparisons, the tomato leaf sample was infected by a geminivirus isolate belonging to the Israeli species of TYLCV and was most closely related to the Dominican Republic isolate (98.4% nucleotide identity). In symptomless plants from which a 500-bp PCR product was obtained, infection may have been in an early stage. This is consistent with the fact that in the 2-ha field from which tomato samples were collected, only 4% of the plants exhibited TYLCV symptoms at the time of collection, whereas at least 70% of plants showed symptoms later, requiring the farmer to abandon the crop. The presence of the Eastern Mediterranean TYLCV species in a Western Mediterranean country is not a new observation; this virus has been described in Spain and Portugal (1). In Morocco, TYLCV symptoms were observed during the 1996 to 1997 growing season, following importation of grafted tomato plants from the Netherlands, by a farmer from the Casablanca region. References: (1) J. Navas-Castillo et al. Plant Dis. 83:29, 1999. (2) M. Peterschmitt et al. Plant Dis. 83:303, 1999. (3) P. Umaharan et al. Phytopathology 88:1262, 1998.
First Report of Capsicum annuum Plants Infected by Tomato Yellow Leaf Curl Virus
Authors: Reina J. , Morilla G. , Bejarano E. R. , Rodríguez M. D. , Janssen D. 
Published: May 2007

Infection of tomato crops by tomato yellow leaf curl virus (TYLCV) has occurred annually in southern Spain since 1992. In 1997, TYLCV also was reported in common bean (Phaseolus vulgaris) (2) in southern Spain. During the summer of 1999, we observed pepper plants (Capsicum annuum) from a greenhouse in Almería (Spain) exhibiting clear leaf internervial and marginal chlorosis and upward curling of the leaflet margin. Total nucleic acids were extracted from five plants with symptoms and analyzed by Southern blot hybridization and polymerase chain reaction (PCR). As a probe, we used a plasmid (pSP72/97) encompassing the complete genome of the Spanish isolate of TYLCV-IS (1). A positive signal was obtained from three samples. A pair of primers (OTYA3/OTYA6) designed to amplify TYLCV was used for detection in samples (OTYA3: GGGTCGACGTCATCAATGACG; OTYA6: CTACATGAGAATGGGGAACC). Using PCR, we were able to obtain fragments of the expected sizes (649 bp for OTYA3/OTYA6) from four of five samples analyzed. Amplified fragments were later analyzed by restriction fragment length polymorphism with three cutter enzymes (AluI, RsaI, and HinfI). The restriction pattern obtained in all cases corresponded with the Spanish isolate of TYLCV-IS. One of the fragments amplified with OTYA3/OTYA6 was fully sequenced. The sequence was 100% identical to that previously reported for the Spanish isolate of TYLCV-IS. This is the first report of TYLCV infection in C. annuum, which is one of the most important commercial crops in southeastern Spain. Work is in progress to determine whether the presence of TYLCV-IS in pepper plants is responsible for the symptoms described here. References: (1) J. Navas-Castillo et al. Plant Dis. 81:1461, 1997. (2) J. Navas-Castillo et al. Plant Dis. 83:29, 1999.
First Report of Powdery Mildew on Dollar-plant (Crassula ovata) Caused by an Oidium sp.
Authors: Kiss L. 
Published: May 2007

Dollar-plant (Crassula ovata) is a perennial, succulent ornamental grown worldwide. In 1998, powdery mildew colonies were observed on the adaxial leaf surfaces of a 4-year-old specimen maintained outdoors. Symptoms included necrosis of the infected tissues and defoliation 2 months after the appearance of the first colonies. Conidia were produced in chains on unbranched conidiophores. Hyphal appressoria were lobed to multi-lobed, mostly opposite or spread. Conidia were ellipsoid to cylindrical, measured 34 to 48 μm × 17 to 26 μm, and contained no fibrosin bodies. On water agar, conidia produced a single germ tube from the end of the conidium. Germ tubes were either very short with lobed appressoria, or were two to three times longer than conidia, and terminated in lobed or unlobed appressoria. Cleistothecia were not produced. The pathogen was identified as an Oidium sp. belonging to the genus Erysiphe sect. Galeopsidis (1). To confirm pathogenicity, small, potted C. ovata plants were placed near the diseased plant in the laboratory. After 2 weeks, powdery mildew appeared on the small plants, and the pathogen was morphologically identical to the original fungus. This is the first report of a powdery mildew fungus on C. ovata, and it is different from both species of the Erysiphaceae identified on other Crassula spp. (1,2). Infected C. ovata leaves were deposited at the Department of Botany of the Hungarian Natural History Museum in Budapest under the accession number BP 91732. References: (1) U. Braun. 1995. The Powdery Mildews (Erysiphales) of Europe. Gustav Fischer Verlag, Jena. (2) D. F. Farr et al. 1989. Fungi on Plants and Plant Products in the United States. American Phytopathological Society, St. Paul, MN.
First Report of the Teleomorph of an Oidium sp. Causing Powdery Mildew on Flowering Dogwood in South Carolina
Authors: Williamson M. R. , Blake J. H. 
Published: May 2007

Prior to 1994, powdery mildew had rarely been reported on flowering dogwood (Cornus florida) in the southeastern U.S. That year, and every year since, epiphytotics of powdery mildew have occurred. Leaf symptoms include distortion and necrotic areas on young leaves and an increase in red pigmentation surrounding infection sites. Young seedlings may be stunted by this disease and growth of older trees may be slowed (2). In early November, 1996, dogwood (C. florida) trees at 10 locations each in Anderson, Oconee, and Pickens counties in northwestern South Carolina were surveyed for the presence of powdery mildew. Leaves with signs of powdery mildew (white, powdery patches of mycelium, conidiophores, and conidia) were examined with a ×10 hand lens and leaves with cleistothecia were collected and taken back to the laboratory. Numerous leaves from each site were first examined at ×50 on a dissecting microscope to observe gross morphological features of cleistothecia. Then, approximately 10 cleistothecia from each of two sites were examined on a compound microscope at ×100 or higher to make further observations and measurements. Cleistothecial diameter ranged from 75.0 to 92.5 μm (average 81.8 μm). Appendages, which averaged 6 to 11 per cleistothecium, were 110 to 140 μm long (average 125.7 μm) or 1.54 times the cleistothecial diameter. The apices of appendages were dichotomously branched 2 to 3 times and the tips were distinctly re-curved. The stalks were aseptate and hyaline. Cleistothecia contained 3 to 5 asci. Each ascus contained 2 to 6 ascospores measuring 18 to 28 × 13 to 15 μm. Based on these characteristics, the teleomorph was tentatively identified as Microsphaera pulchra. Cleistothecia were found to be slightly smaller and the number of appendages fewer than Braun's lectotype (1), but these differences were judged to be of minor importance. Therefore, we conclude that the teleomorph of the Oidium sp., herein reported on flowering dogwood for the first time in South Carolina, is Microsphaera pulchra References: (1) U. Braun. Nova Hedwigia 89:1, 1987. (2) L. A. Klein et al. Plant Dis. 82:383, 1998.