bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Powdery Mildew on Asclepias curassavica in Italy
Authors: Garibaldi A. , Minuto A. , Bertetti D. , Gullino M. L. 
Published: May 2007

Asclepias curassavica is grown in Italy for landscape use in parks and gardens. In 2001, severe outbreaks of a previously unknown powdery mildew were observed in commercial farms located in Albenga (northern Italy). Powdery mildew developed on the lower surface of leaves of container grown plants. The upper surface of infected leaves turned reddish and sometimes yellow. Infected tissues wilted, and leaves dropped prematurely. Conidiophores emerged through the stomata. Conidia were hyaline and had variable shape, mitrate when located at the apex of the conidiophore, and subcylindric when borne in the middle of a chain. Conidia measured 46 to 74 × 12 to 24 μm. Cleistothecia were not observed. The causal agent was identified as Oidiopsis sp. Pathogenicity was confirmed by gently pressing diseased leaves on leaves of healthy A. curassavica plants. Plants were maintained in a growth chamber at 20 to 24°C after inoculation. After 12 to 14 days, powdery mildew signs developed. Leveillula taurica has been reported as causal agent of powdery mildew on A. carassavica in India and on Asclepias sp. in Morocco (1). Also in our case, L. taurica should be the causal agent, since the genus Leveillula has as anamorph the genus Oidiopsis (2). In Switzerland, Phyllactinia suffulta has been described as incitant of a similar powdery mildew on A. syriaca. References: (1) G. Bergen. Ann. Epiphyt. Nuove Serie, IV, 1:21, 1938. (2) J. Palti. The Bot. Rev. 54:423, 1988.
Macroptilium yellow mosaic virus, a New Begomovirus Infecting Macroptilium lathyroides in Cuba
Authors: Ramos P. L. , Fernández A. , Castrillo G. , Díaz L. , Echemendía A. L. , Fuentes A. , Peral R. , Pujol M. , Ascencio-Ibañez J. T. , Rivera-Bustamante R. , Arguello-Astorga G. 
Published: May 2007

Macroptilium lathyroides (L) is a weed that is widely distributed in Cuba. Frequently, leaves show bright yellow mosaic symptoms, which suggest the incidence of a viral disease. Since begomovirus occurrence in Macroptilium lathyroides has been previously reported in other islands of the Caribbean (1,3), symptomatic plants from three distant places in Cuba (Havana, Villa Clara, and Camaguey), were collected and tested for the presence of begomoviruses. Plant DNA extracts were analyzed by Southern blot hybridization and polymerase chain reaction with two sets of degenerate primers (2). The presence of a bipartite begomovirus was evident through strong hybridization signals obtained with the DNA-A and DNA-B of Taino tomato mottle virus as probes at low stringency. Furthermore, 1.4-kb and 1.2-kb PCR amplified fragments were obtained with DNA-A degenerate primers, PAL1v1978-PAR1c715 and PAL1c1960-PAR1v722, respectively. Both PCR fragments from the samples from the three locations were cloned, and restriction fragment length polymorphism analysis of the 1.4-kb fragments were performed using PstI, EcoRI, HincII, XbaI and BglII. Restriction fragment patterns were the same for the three clones. The DNA-A sequence (GenBank Accession No. AJ344452) of the isolate from Villa Clara was compared with sequences available for other geminiviruses using CLUSTAL program. For the coat protein (CP) gene, the comparisons had the highest percentage of identity with various strains of Bean golden yellow mosaic virus (BGYMV, GenBank Accession Nos. AF173555, M91604, and L01635) (85 to 87% and 93 to 94%, nucleotide and amino acid sequences, respectively). For Rep gene (1,044 nt), the best percentages of identities were with BGYMV (81 to 82% and 80 to 82% nucleotide and amino acid sequences, respectively), Tomato leaf crumple virus (GenBank Accession No. AF101476) (78 and 81%, nucleotide and amino acid sequences, respectively), and Sida golden mosaic virus from Florida (GenBank Accession No. AF049336) (78 and 79%, nucleotide and amino acid sequences, respectively). Finally, the comparative analysis of the intergenic region (i.e. the common region plus the CP gene promoter) had the highest identity with BGYMV (56 to 55%) and Tomato severe rugose virus (GenBank Accession No. AY029750) (49%). Interestingly, this virus has in this region the three G-box elements that are characteristic of BGYMV but it differs in the Rep protein-binding iterative motif that is GGTGA instead of GGAGA, for BGYMV. These data indicate that this virus is a new begomovirus and the name of Macroptilium yellow mosaic virus (MaYMV) is proposed. References: (1) A. M. Idris et al. Plant Dis. 83:1071, 1999. (2) M. R. Rojas et al. Plant Dis. 77:340, 1993. (3) M. E. Roye et al. Plant Dis. 81:1251, 1997.
Fusarium Fruit Rot of Greenhouse Sweet Peppers in Canada
Authors: Utkhede R. , Mathur S. 
Published: May 2007

In the summer of 2001, a fruit rot of orange sweet peppers (Capsicum annum L. cv. Sympathy MZ) was observed in commercial greenhouses in British Columbia, Canada. According to the grower's estimate, approximately 40% of fruits in the commercial greenhouse were severely affected in the year 2001 and approximately 10% in 2002. The disease appeared on mature fruits at harvest time, and affected fruits are considered as culls. The disease appeared as discolored soft patches or necrotic spots predominantly at the calyx end and occasionally, anywhere on the mature fruit at harvest time. Seeds and the surrounding area inside the fruits were covered with fungal growth and orange-pink spore masses. Five fungal isolations were made from the lesions. Infected tissues from the edge of lesions were surface sterilized in 1% sodium hypochlorite for 2 min, blotted dry on sterile filter paper, and cultured on potato dextrose agar (PDA). Plates were incubated at 22°C for 7 days. Single spore fungal colonies isolated from the tissues yielded Fusarium sp. Only one fungal species was consistently isolated from affected pepper fruits. Morphology of the fungus was consistent with Fusarium subglutinans (Wollenweber & Reinking) Nelson et al. according to Keith Seifert of Eastern Cereal and Oilseed Research Centre, Ottawa, Canada. Molecular tests are being developed to confirm the identification of the fungus. To confirm pathogenicity, 10 flowers and developing fruits of sweet pepper cv. Sympathy MZ grown in a greenhouse were inoculated with the pathogen. For inoculation, 20 μl of spore suspension of the fungus (concentration 106 spores/ml) was drop-inoculated on the wounded and unwounded surfaces of fruits. To inoculate flowers, a spore suspension was drop-inoculated in the middle of flowers without any wounding. Controls were treated with 20 μl of sterile water. The experiment was repeated once. Approximately 80% of inoculated fruits and flowers developed symptoms on fruits similar to naturally infected fruits at maturity. Fruits from control plants did not develop any disease. On PDA, a Fusarium species identical to the original one was recovered from all inoculated infected fruits. A preliminary study showed that this pathogen does not infect other greenhouse crops such as tomato, cucumber, or lettuce. Sweet pepper stem and fruit rot caused by Fusarium solan has been reported previously (1) but there is no report of fruit rot caused by a Fusarium subglutinans-like species on greenhouse sweet peppers. Reference: (1) J. G. Menzies and W. R. Jarvis. Fusarium stem and fruit rot. Pages 333–334 in: Diseases and Pests of Vegetable Crops in Canada. R. J. Howard et al. eds. The Canadian Phytopathological Society and Entomological Society of Canada, 1994.
First Report of Phakopsora pachyrhizi, the Causal Organism of Soybean Rust in the Province of Misiones, Argentina
Authors: Rossi R. L. 
Published: May 2007

In April 2002, Phakopsora pachyrhizi Sydow was observed for the first time in L. N. Alem, in the Province of Misiones, Argentina. Misiones is nearly surrounded by Paraguay and Brazil, where P. pachyrhizi was discovered recently (2) and where it is a serious disease (3). Symptoms were observed on leaves in the upper half of plants at the R6 stage in a soybean research field trial. Symptoms included reddish-brown lesions on leaves especially on the abaxial surface, and uredinias were observed in the lesions with a 10× lens. Leaf defoliation was observed due to the disease after the R5 stage, and the enviroment (high humidity and air temperatures) was particularly conducive to the disease. The field trial area was 2,500 m2 and included soybean genotypes of maturity groups V to IX. Symptoms were detected in the later maturity groups. Field trials were surrounded by kudzu (Pueraria sp.), which is a common weed introduced in South America as a forage plant by Asian farmers, and it was reported as the main host of this pathogen in Paraguay (2). To confirm the identity of the pathogen, leaf samples from the middle part of plants were collected and sent to the Foreign Disease-Weed Science Research Unit, Ft. Detrick, MD. Samples were analyzed using a real-time polymerase chain reaction assay (1). Identification of P. pachyrhizi was confirmed the last week of May, 2002 (R. Frederick, personal communication). The soybean production area in Misiones is a small area in Argentina lying 600 km northeast of the main soybean area in the north central part of the country. SENASA (Servicio Nacional de Sanidad Vegetal [Nacional Service of Plant Health]) and SAGPYA (Secretary of Agriculture) were formally informed about these results on June 19, 2002. A program to assess the risk of disease spread is under development. References: (1) R. D. Frederick et al. Phytopathology 92:217, 2002. (2) W. Morel Paiva. AnaisII Congresso Brasilero de Soja e Mercosoja. Foz de Iguazu, Brazil, 2002. (3) T. Yorinori. Anais II Congresso Brasilero de Soja e Mercosoja. Foz de Iguazu, Brazil, 2002.
First Report of Turnip mosaic virus in Pisum sativum in Spain
Authors: Segundo E. , Martín-Bretones G. , Ruiz L. , Velasco L. , Janssen D. , Cuadrado I. M. 
Published: May 2007

During 2001 and 2002, Pisum sativum var. vulgare plants grown as commercial crops in Almeria (southeast Spain) showed vein clearing and chlorotic mottle of leaves, leaf deformation, flower abortion, necrotic mottle and deformation of pods, and stunted plant growth. Crude sap of collected plants was mechanically inoculated on healthy pea plants which reproduced symptoms observed in the field; local necrotic lesions were produced on mechanically infected Chenopodium quinoa, C. amaranticolor, and Gomphrena globosa, systemic mosaic symptoms on Brassica napus and Nicotiana benthamiana, and local lesions plus systemic mosaic symptoms on N. clevelandii, which are all characteristic of Turnip mosaic virus (TuMV) (1). A reverse transcription-polymerase chain reaction assay using general primers for the extreme 3′ end of the potyvirus genome amplified products of 750 and 1,700 bp in nucleic acid extracts from naturally infected pea plants as well as from the mechanically infected test plants. The overlapping nucleotide sequences of the products (GenBank Accession No. AJ489259) had a nucleotide sequence identity of 86.5% and a derived amino acid identity of 95.0% with several published sequences of TuMV (1). This report cites the first partial nucleotide sequence of TuMV infecting pea crops, and although natural infections of this virus in pea have been reported in Morocco (1976) and in the United States (2), to our knowledge, this is the first report of TuMV in Spain. References: (1) P. Lehmann et al. Physiol. Mol. Plant Pathol. 51:195, 1997. (2) R. Provvidenti. Plant Dis. Rep. 62:482, 1978.
Occurrence of the Root-Knot Nematode Meloidogyne hapla in the Czech Republic
Authors: Zouhar M. , Rysanek P. , Tesarova B. 
Published: May 2007

Meloidogyne hapla was detected in several commercial vegetable fields in the Province of Central Bohemia in the Czech Republic. Crops grown in the area of infestation include leek, onion, cauliflower, early potatoes, and carrot. During the past 2 to 3 years, growers have observed typical symptoms of Meloidogyne infection as stunting and galls on roots of carrot. Identification of the causal organism was based on microscopic observation of the perineal patterns of females obtained from root galls and polymerase chain reaction (1,2). Known isolates of M. chitwoodi, M. arenaria, M. javanica, M. incognita, and M. fallax from M. Phillips (SCRI, Dundee) and C. Zijlstra (PRI, Wageningen), and M. hapla from M. Liskova (PI, Kosice) were used as controls. M. hapla was identified in galled roots using both methods. Several fields with carrots were inspected in the area during vegetation in 2000 and 2001. In most fields, only isolated and limited outbreaks occurred, but recently, we observed a widespread and fairly homogeneous occurrence of root knot attributed to M. hapla in a 2-ha field. This nematode may become a more widespread and damaging pest, especially of carrot, in the Czech Republic. Other than carrot, vegetable crops grown in the area and tested in the greenhouse and field in soil highly infested by our isolates of M. hapla had no visible symptoms of infection. Therefore, exclusion of carrot cultivation or a longer crop rotation is recommended to minimize economic losses to growers. To our knowledge, this is the first report of the occurrence of M. hapla in the Czech Republic. References: (1) T. S. Harris et al. J. Nematol. 22:518, 1990. (2) C. Zijlstra et al. Genetics 85:1231, 1995.
First Report of Pestalotiopsis maculans Causing Necrotic Leaf Spots in Nursery Plants of Arbutus unedo and Ceratonia siliqua in Spain
Authors: Trapero A. , Romero M. A. , Varo R. , Sánchez M. E. 
Published: May 2007

Forestation of agricultural lands has led to a great increase in the production of plants in forest nurseries in southern Spain. During a disease survey of several nurseries, performed in 1998 and 1999, a necrotic leaf spot was found causing defoliation in seedlings of two mediterranean forest species, the ericaceous shrub Arbutus unedo and the leguminous tree Ceratonia siliqua. The affected plants were 9 to 24 months old and growing in fertilized peat in containers. Symptoms on both species consisted of large necrotic lesions (up to 20 mm in diameter) that were located mainly, but not exclusively, along the leaf margin. On A. unedo, necrotic spots were bordered by a red halo, while on C. siliqua the halo was dark. The fungus consistently isolated from both hosts was identified as Pestalotiopsis maculans (Corda) Nag Raj (=Pestalotiopsis guepinii), based on morphological characters (1). Acervular conidiomata (up to 200 μm in diameter) developed on the necrotic lesions of leaves incubated at 100% relative humidity and 20 to 24°C, and in cultures on potato dextrose agar (PDA) at 20 to 24°C over the course of 7 days. All isolates had 5-celled smooth conidia. Apical and basal cells were hyaline, while the three median cells were brown; the upper two were darker than the lower one. Conidia were 22 to 30 μm (mean length) and 5 to 9 μm (mean width). There were typically three (range 1 to 4) apical appendages averaging 17 μm long. The average basal appendage was 6 μm long. One-year-old seedlings and detached leaves from healthy field trees of A. unedo and C. siliqua were sprayed to runoff with an aqueous conidial suspension (106 conidia ml-1) of two isolates of the fungus. All inoculated and control plants sprayed with water only were incubated in a growth chamber at 100% relative humidity and 20 to 24°C for 48 h and then in the same growth chamber at 50 to 80% relative humidity or in the greenhouse (10 to 30°C and 40 to 80% relative humidity) until symptoms developed. Detached leaves were incubated to prevent desiccation in a humid chamber at 100% relative humidity and 20 to 24°C for 2 months. After a period of 2 to 4 months, lesions developed on all inoculated leaves but not on noninoculated controls. Lesion morphology on both hosts was similar to that observed in naturally infected plants in the nurseries. P. maculans was reisolated from lesions of all infected leaves but not from control leaves. Although other species of Pestalotiopsis have been reported infecting leaves of C. siliqua (1), to our knowledge, this is the first report of a Pestalotiopsis sp. on A. unedo and of P. maculans on C. siliqua. Reference: (1) T. R. Nag Raj. Coelomycetous Anamorphs with Appendage-Bearing Conidia. Mycologue Publications, Waterloo, Ontario, Canada, 1993.
First Detection of Phytophthora ramorum Mating Type A2 in Europe
Authors: Werres Sabine , De Merlier Daphné 
Published: May 2007

Since its original isolation in 1993, Phytophthora ramorum has become an important pathogen. Initially, it was determined to be the causal agent of a twig blight of Rhododendron spp. in Germany and the Netherlands (3). Around the same period, symptoms and mortality on oak (Quercus spp.) and tanoak (Lithocarpus densiflorus) were associated with P. ramorum in California (2), where the disease was named sudden oak death. Subsequently, P. ramorum has been detected on a wide range of forest trees and shrub species in the United States. In Europe, the pathogen has spread to many countries, primarily on nursery plants of Rhododendron and Viburnum spp., and recently, on Camellia japonica, Kalmia latifolia, Pieris formosa var. forrestii, P. japonica, Leucothoe sp., Syringa vulgaris, and Taxus baccata. P. ramorum has not been observed in European forests. P. ramorum is heterothallic, and initial in vitro mating studies on agar media suggested that only the A1 mating type occurred in Europe, while only the A2 mating type was present in the United States (4). However, an isolate collected in 2002 in Belgium (1) appears to be the A2 mating type. This isolate (CBS 110901, Centraal Bureau voor Schimmelcultures, Baarn, the Netherlands) originated from an imported V. bodnantense plant at an ornamental nursery. A hyphal tip culture (BBA 26/02) of this isolate produced no oogonia on carrot piece agar after 6 weeks in pairing tests with other Phytophthora species of mating type A2. When paired with mating type A1 of P. cambivora, P. cinnamomi, P. cryptogea, and P. drechsleri, however, oogonia were observed in all pairings within 6 weeks. The number of oogonia was low in all pairings but was highest in pairings with P. cryptogea. No oospores were produced after 6 weeks between P. ramorum isolates BBA 26/02 and BBA 9/95 (from the holotype, mating type A1), but gametangia were observed when these isolates were paired on Rhododendron sp. twigs. Normal oogonia were produced on the outgrowing mycelium when pieces from these twigs were placed on carrot piece agar. The shape and size of the oogonia produced on carrot piece agar after pairing with P. cryptogea and on Rhododendron sp. twigs after pairing with P. ramorum BBA 9/95 were similar (24 to 34 μm, mean 29.6 μm and 25 to 33 μm, mean 30.6 μm, respectively). To our knowledge, this is the first observation of P. ramorum mating type A2 in Europe. References: (1) D. De Merlier et al. Plant Dis. 87:203, 2003. (2) D. M. Rizzo et al. Plant Dis. 86:205, 2002. (3) S. Werres et al. Mycol. Res. 105:1166, 2001. (4) S. Werres and B. Zielke. J. Plant Dis. Prot. 110:129, 2003.
First Report of Puccinia xanthii on Xanthium italicum in Eastern Hungary
Authors: Dávid I. , Harcz P. , Kövics G. J. 
Published: May 2007

In 2002, in Debrecen, eastern Hungary, Puccinia xanthii Schwein. was detected on hunter burr, a geographically spreading, noxious weed species in row crops. Symptoms were found on leaves, stems, and petioles of plants collected from a competition experiment between sugarbeet and hunter burr. Density of the hunter burr population (6 plants per m2 or 20 plants per m2) influenced the rate of infection. In the low-density population, the number of rust pustules and infected leaves was lower than that in the high-density population, in which 70% infection was reached by September. First symptoms appeared at the end of July (high-density population) and in the beginning of August (low-density population) in the form of small, chlorotic raised spots on the underside of the leaves. Dark brown telia (3.8 mm in diameter or larger) developed on spots. Elliptical telia occurred at the rate of 0.02 to 2.37 pustules per cm2. Elongated pustules caused swelling and epidermal splitting on stems and petioles. Teliospores were brown, two-celled, and 35 to 56 × 15 to 21 μm, the walls were 0.8 to 1.0 μm at the side and 5 to 8 μm at the apex, the septum was 1 to 1.5 μm, and a persistant pedicel was 15 to 50 μm. Size and morphology of teliospores fit the description of P. xanthii (2). A pathogenicity test was conducted in the greenhouse (24°C with high relative humidity) according to the “leaf disc method” of Morin et al. (1) using freshly collected hunter burr leaves. Teliospores germinated immediately, producing metabasidia, and basidiospores were produced within 5 h. The first macroscopic symptoms on test plants were observed 4 days after inoculation. Approximately 8 days after inoculation, developing telia arose from the thallus and began to erupt through the epidermis. Developed teliospores on artificially inoculated plants were morphologically identical to those from leaves collected in the field. Control plants did not develop symptoms. This microcyclic rust occurs in several regions of the world, including several southern European countries. This rust is a potential biological agent for the control of Xanthium spp.; however, it can infect several cultivars of sunflower (1). To our knowledge, this is the first report of P. xanthii in Hungary. References: (1) L. Morin et al. Can. J. Bot. 71:959, 1993. (2) J. A. Parmelee. Can. J. Bot. 47:1391, 1969.