bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Virulence in Puccinia graminis f. sp. tritici to Wheat Stem Rust Resistance Genes Sr8b and Sr38 in South Africa
Authors: Boshoff W. H. P. , Pretorius Z. A. , van Niekerk B. D. , Komen J. S. 
Published: May 2007

During the 2000 to 2001 season, 27 stem rust samples were collected from wheat (Triticum aestivum), barley (Hordeum vulgare), and triticale (× Triticosecale) cultivars and lines in the Western Cape, South Africa. Following inoculation and multiplication on McNair 701 seedlings, 40 single pustule isolates of P. graminis f. sp. tritici were established. Twenty-six isolates obtained from wheat, barley, or triticale that produced a similar reaction pattern on a set of differentiating host lines, were designated as pathotype Pgt-2SA55. Pgt-2SA55 is avirulent to Sr5, -6, -7b, -8b, -9b, -9e, -9g, -23, -24, -27, -30, -38, and -Gt, and virulent to Sr11, and -Agi. The remaining 14 isolates, all from wheat and designated as pathotype Pgt-2SA88, were avirulent to Sr24, -27, and -Agi, and virulent to Sr5, -6, -7b, -8b, -9b, -9e, -9g, -11, -23, -30, -38, and -Gt. On an expanded differential set, representative isolates of each pathotype were all avirulent to Sr13, -15, -21, -22, -25, -26, -29, -31, -32, -33, -35, -39, -43, and -Em, and virulent to Sr7a, -8a, -9a, -9d, -9f, -10, -12, -14, -16, -19, -20, -34, and Lc. Pgt-2SA55 was avirulent on cv. Renown (Sr2, -7b, -9d, and -17), whereas Pgt-2SA88 was virulent on this cultivar and Line R Sel carrying only Sr17. Both pathotypes differ from those identified previously in South Africa (1) and to our knowledge, Pgt-2SA88 is the first local isolate to have virulence towards Sr8b and the T. ventricosum-derived gene Sr38. Virulence to Sr38 has been reported in a P. graminis f. sp. tritici isolate collected in Uganda (2). Pathotype Pgt-2SA88 is virulent to seedlings of the previously resistant South African cvs. SST 57 (heterogeneous), Tugela, Tugela DN, and PAN 3377. Furthermore, 20% of the elite breeding lines in the spring and winter wheat breeding program of the Small Grain Institute expressed susceptible seedling reactions to Pgt-2SA88. Triticale cvs. Rex and Kiewiet were heterogeneous in their seedling reaction towards Pgt-2SA55. Seedling and field reactions recorded for the barley cvs. Sterling and SSG 532 and the experimental varieties Puma and Jaguar, showed an increase in stem rust susceptibility to Pgt-2SA55 when compared with existing South African pathotypes. The higher incidence of stem rust in commercial fields and experimental plots of wheat and barley in the Western Cape may be attributed to a recent increase in the cultivation of stem rust-susceptible cultivars in the region. The detection of two new pathotypes of P. graminis f. sp. tritici is of concern to the local small grain industry and requires continued resistance breeding. References: (1) W. H. P. Boshoff et al. S. Afr. J Plant Soil 17:60, 2000. (2) Z. A. Pretorius et al. Plant Dis. 84:203, 2000.
First Report of Phytophthora capsici Infecting Lima Bean (Phaseolus lunatus) in the Mid-Atlantic Region
Authors: Davidson C. R. , Carroll R. B. , Evans T. A. , Mulrooney R. P. , Kim S. H. 
Published: May 2007

Lima beans are an important crop in Delaware and the Mid-Atlantic Region. In the summer of 2000, five commercial cultivars (3–28, 184–85, C-elite Sel, Butter Bean, and Jackson Wonder) of lima bean in Delaware, Maryland, and New Jersey were observed with white, appressed mycelia on infected pods that appeared distinctly different from signs of downy mildew infection caused by Phytophthora phaseoli. Isolations were made by placing diseased pods between layers of rye media (1). A fungus that produced white mycelia with sporangia was consistently isolated. All Phytophthora isolates from the infected pods were heterothallic, grew at 35°C, had as much as 100 μm long pedicles on varying shapes of caducous sporangia with tapering base and >2 papillae, and were identified as P. capsici (2). Initially, three surface-disinfected pods from cv. Early Thorogreen plants grown in the greenhouse were floated on 20 ml of sterile water in a petri dish, and each was inoculated with a disk of P. capsici. This was repeated for nine isolates obtained from lima bean. After incubation for 7 days at room temperature, all 27 pods were infected, and P. capsici was reisolated from all the pods. A pathogenicity test was performed on the same cultivars from which the original field isolates were collected. Three seedlings and two plants with mature pods were inoculated with a sporangial suspension of each of the nine isolates and placed in a dew chamber for 5 days at 20 to 25°C and 100% relative humidity. White mycelial growth was observed on seedlings and mature pods. One inoculated plant developed brown-to-black stem lesions with white mycelia. All pods on the mature plants showed appressed, white mycelia identical to that observed in the commercial lima bean fields. P. capsici was consistently reisolated from all inoculated plants. In 2000, most infected pods in infested fields were observed low in the plant canopy or touching the soil. However, in 2001, infected pods were mostly in the lower and mid-portion of the plants observed in baby lima bean fields in Kent County, DE. References: (1) C. E. Caten and J. L. Jinks. Can. J. Bot. 46:329, 1967. (2) D. C. Erwin and O. K. Ribeiro. Phytophthora capsici. Page 264 in: Phytophthora Diseases Worldwide. The American Phytopathological Society, St Paul, MN, 1996.
A New Race of Pyrenophora tritici-repentis from Brazil
Authors: Ali S. , Francl L. J. 
Published: May 2007

Pyrenophora tritici-repentis causes tan spot of wheat worldwide. Fungal isolates have been characterized into seven races based on their ability to induce necrosis and chlorosis on appropriate wheat differentials (1,2). Nineteen single-spore isolates of P. tritici-repentis were recovered from diseased wheat leaves collected from Brazil. The isolates were tested for their race structure by individually inoculating a suspension of 3,000 conidia per ml on wheat differential seedlings at the 2-leaf stage in the greenhouse. The isolates were tested three times and consistent results were found. The differential set was comprised of Glenlea, Katepwa, ND495, 6B365, Salamouni, and M-3. Seven of the 19 isolates were grouped into race 1 because they produced necrosis on Glenlea, Katepwa, and ND495; chlorosis on 6B365; and neither symptom on Salamouni and M-3. Twelve of the isolates produced necrosis on Glenlea, Katepwa, ND495, 6B365, and Salamouni, and neither symptom on M-3. Necrotic reactions to these isolates on 6B365 (chlorotic or resistant to currently identified 7 races) and Salamouni (resistant to all 7 races), and the resistant reaction on M-3 (resistant to all 7 races) differentiate them from the other seven races. Therefore, we grouped these isolates under a new race and designated this as race 8. To our knowledge, this is the first report on the occurrence of race 8 in P. tritici-repentis. This discovery holds particular significance to breeders and pathologists interested in producing wheat lines with resistance to tan spot. Additionally, we suggest that M-3 be added to the differential set because this line is resistant to all eight identified races. More isolates from Brazil are under investigation to discover the P. tritici-repentis race structure in the country. References: (1) S. Ali et al. (Abstr.) Phytopathology 92(suppl):S3, 2002. (2) S. E. Strelkov et al. Can. J. Plant Pathol. 24:29, 2002.
A New Soilborne Disease of Dry, Edible Beans in Western Nebraska
Authors: Harveson R. M. 
Published: May 2007

During July 2001, wilting, dry bean plants (Phaseolus vulgaris L.) at the 3- to 4-leaf stage were observed in a field near Ogallala, NE. Affected plants exhibited dark brown lesions on the hypocotyls and lower stems. Isolations from lesions on diseased plants on potato dextrose agar (PDA) yielded several isolates of an unknown fungus containing binucleate hyphal cells and numerous clamp connections. After growth on PDA for 6 weeks, all fungal isolates remained sterile and did not produce identifying spores, chlamydospores, or sclerotia. Two of the recovered field isolates were randomly selected for pathogenicity tests. Great Northern bean plants (cv. Beryl) were grown in a peat moss/perlite mix (3:1) in 10-cm plastic pots and inoculated separately with each of the two isolates at the two-true leaf stage. Two-week-old cultures grown on PDA (two 100 × 15 mm plates) were ground in 400 ml water in a blender for 3 to 4 min. Approximately 50 to 60 ml of the mycelial suspension was drenched around stems in each pot (two plants per pot), and incubated in growth chambers at 20, 30, and 35°C with a 12-h photoperiod. Six replicates were used for each isolate/temperature combination. After 4 weeks at both 30 and 35°C, fungi were consistently reisolated from stem lesions of wilting plants like those from the field-infected specimens. These fungi were also morphologically identical to the original isolations, thus confirming pathogenicity of the isolates and completing Koch's postulates. No disease was observed at 20°C. The pathogenicity evaluations were repeated twice with similar results. A group of fungi initially called sterile, white, basidiomycetes (SWBs) have been reported causing disease in other legumes from subtropical climates, including snap bean (2,4) and pigeon pea (3). Similar fungi isolated from bermudagrass were identified as Marasmius spp. after induction of sporocarps in vitro (1). The Nebraska isolates appear to be similar, if not identical to those from previous reports (1,2,3), but will be referred to as SWBs until a teleomorph has been identified. To my knowledge, this is the first report of these pathogens on dry, edible beans and on a legume crop from a temperate climate. References: (1) R. E. Baird et al. Plant Dis. 76:244, 1992. (2) C. M. Howard et al. Phytopathology 67:430, 1976. (3) W. J. Kaiser et al. Plant Dis. 71:1006, 1987. (4) D. R. Sumner et al. Plant Dis. Rep. 63:981, 1979.
First Report of the Dagger Nematode Xiphinema rivesi, a Member of the X. americanum Group, from Slovenia
Authors: Urek G. , Širca S. , Kox L. , Karssen G. 
Published: May 2007

The dagger nematode, Xiphinema rivesi Dalmasso, is a virus-transmitting plant-parasitic nematode described from France (2) and also reported from Germany, Portugal, and Spain. While this species is only known from a few local sites within Europe, it is widespread in North America and also present in Peru and Pakistan (3). X. rivesi is able to transmit at least four North American nepoviruses, including Cherry rasp leaf virus, Tobacco ringspot virus, Tomato ringspot virus, and Peach rosette mosaic virus (1,4). In early spring 2002, nematodes of the X. americanum group were detected in soil samples taken near the roots of peach plants from an orchard in Bilje near Nova Gorica, Slovenia. Resampling in June and September at the same site and at an adjacent, approximately 30-year-old peach orchard confirmed the presence of the nematode in relatively high numbers (5 per 100 ml of soil). Adult females were isolated and sent for further identification to the Plant Protection Service in Wageningen, the Netherlands. The nematode was morphologically identified as X. rivesi and confirmed at the rDNA-level with internal transcribed spacer restriction fragment length polymorphism analysis. Because both sampling sites where the nematode was found are close to the Vipava River in an area of extensive stone and pome fruit production, it is likely that the nematode is also present in other orchards in this region. The origin of this quarantine nematode is unknown as there is no direct link with Slovenian orchards and import of plant material from abroad in the last decades. To our knowledge, this is the first report of X. rivesi in Slovenia and the fourth report of this species in Europe. References: (1) D. J. F. Brown et al. Phytopathology 84:646, 1994. (2) A. Dalmasso. Mem. Mus. Hist. Nat. Nouv. Série A., Zool. 61:33, 1969. (3) Data Sheets on Quarantine Pests: Xiphinema americanum sensu lato. Page 629 in: Quarantine Pest for Europe, CABI, Wallingford, UK, 1997. (4) L. W. Stobbs et al. Plant Dis. 80:105, 1996.
First Report of the Potato Cyst Nematode (Globodera pallida) in the Czech Republic
Authors: Zouhar M. , Rysanek P. , Gaar V. 
Published: May 2007

Potato cyst nematode, Globodera pallida, was detected in several soil samples collected from various areas of the Czech Republic. Globodera rostochiensis pathotype Ro1 is known to be widespread in the Czech Republic. G. pallida was reported from the neighboring countries of Austria, Germany, and Poland, and also was suspected to be present in the Czech Republic, but it has never been unambiguously proved (1). Recently, nematode isolates have been recovered that multiply readily on Ro1 resistant potato cultivars. These isolates were identified on the basis of three tests: (i) microscopic observations of cyst vulval area morphology and stylets of second-stage larvae; (ii) enzyme-linked immunosorbent assay using a commercial kit; and (iii) a polymerase chain reaction method (2). A complete series of G. pallida and G. rostochiensis pathotypes from Scotland and Germany served as controls. Results were identical for all three methods used. One sample contained G. pallida only, five samples contained mixtures of G. rostochiensis and G. pallida, and one sample contained G. rostochiensis only. The origin of G. pallida contamination is unknown. Strict quarantine measures have been taken to prevent G. pallida from spreading into neighboring areas. To our knowledge, this is the first evidence of the occurrence of G. pallida in the Czech Republic. References: (1) J. Potocek et al. EPPO Bull. 21:81, 1991. (2) M. Zouhar et al. Plant Prot. Sci. 36:81, 2000.
First Report of Septoria Blight of Parsley Caused by Septoria petroselini in the Mediterranean Region of Turkey
Authors: Kurt S. 
Published: May 2007

During December 2001 to March 2002, Septoria blight of parsley was observed in approximately 500 ha of commercial parsley crops in Arsuz County, Hatay, in the Mediterranean Region of Turkey. Incidence of disease ranged from 42 to 80%. Symptoms included irregularly shaped, grayish brown spots (average 3 to 8 mm diameter) with a slightly darker brown margin of necrotic tissue that developed into tan-to-brown lesions surrounded by chlorotic halo on the leaves. Oval-shaped lesions were observed occasionally on petioles. Lesions contained erumpent, dark brown, flask-shaped pycnidia with the ostiole on the upper surface of the foliage. Thirty samples, consisting of diseased leaves and petioles of parsley, were collected from each field. Infected tissues were surface-sterilized in 1% NaOCl for 2 min, rinsed in sterile distilled water, placed on petri dishes containing potato dextrose agar (PDA), and incubated for 10 to 14 days at 25°C. The fungus formed long, multiseptate (0 to 4), hyaline, filiform conidia (14 to 29 μm × 0.5 to 1.9 μm), and short conidiophores within the pycnidia. Based on the morphological characteristics of the fungus, the pathogen was identified as Septoria petroselini Desm. (1). Monoconidial cultures of 18 isolates were prepared. Pathogenicity was confirmed by brush-inoculating slightly wounded foliage of 5- to 7- week-old parsley plants (cv. Kereviz yapragi) with a conidial suspension (106 conidia per ml of sterile water) of each isolate of S. petroselini. Control plants that were brush-inoculated with distilled water and inoculated plants were placed in clear polyethylene bags that were closed and incubated at 20°C for 48 h. The bags were removed, and plants were maintained in a dew chamber for 21 days at 65 to 70% relative humidity. Foliar symptoms developed 15 days after inoculation and appeared similar to lesions observed in the field. Yellowing and necrosis of leaves was also observed on >60% of inoculated plants. No lesions developed on the control plants. The pathogen was readily reisolated on PDA from inoculated plants. To our knowledge, this is the first report of Septoria blight of parsley in the Mediterranean Region of Turkey. Reference: (1) R. F. Cerkauskas and J. Uyenaka. Plant Dis. 74:1037, 1990.
Subanguina radicicola, the Root-Gall Nematode Infecting Poa annua in New Brunswick, Canada
Authors: Mitkowski N. A. , Jackson N. 
Published: May 2007

Poa annua frequently is found as the dominant turfgrass species on golf course putting greens grown in the range of cool-season grasses. While not intentionally established, it is an aggressive weed in stands of bentgrasses (Agrostis spp.). When significant encroachment of P. annua occurs, it often is maintained indefinitely. In May 2003, P. annua putting greens at the Riverside Country Club in Rothesay, New Brunswick, Canada showed signs of an unidentified disease. Putting greens were slow to green up and large chlorotic patches were evident across affected areas. When roots were examined, extensive galling was observed. Galls were slender and often twisted in appearance. Upon dissection of washed galls, hundreds of eggs were exuded into the surrounding water droplet, and mature male and female nematodes were observed. Further morphological examination of males, females, and juvenile nematodes demonstrated that they were Subanguina radicicola (Greef 1872) Paramanov 1967 (1,2). Each P. annua plant had an average of four galls (with a range of two to nine) primarily located within the uppermost centimeter of the soil. Of 18 P. annua putting greens, four were affected by the nematode and displayed the same damage symptoms. S. radicicola has been identified from American beachgrass in Rhode Island and from P. annua in Oregon, but to our knowledge, this is the first report of the nematode affecting P. annua on a golf course in eastern North America. References: (1) W. F. Mai and P. Mullin. Plant-Parasitic Nematodes: A Pictorial Key to Genera. Cornell University Press, Ithaca, New York, 1996. (2) G. Thorne. Principles of Nematology. McGraw-Hill Book Company, Inc., New York, 1961
First Report of Peronospora arborescens as the Causal Agent of Downy Mildew on Papaver nudicaule in Italy
Authors: Garibaldi A. , Minuto A. , Bertetti D. , Gullino M. L. 
Published: May 2007

Iceland poppy (Papaver nudicaule L.) is increasingly grown on the Italian Riviera for export as a cut flower. During the spring of 2003, leaves with irregular, brown, angular spots were collected from a commercial crop grown outdoors near Ventimiglia (northern Italy) with temperatures ranging from 3 to 14°C. Leaves of infected plants appeared curled and blistered; the infected portions of the leaves turned chlorotic. On both surfaces of infected leaves, a characteristic gray, furry growth was evident, particularly at the center of the necrotic areas. Infected leaves eventually died without dropping. Basal leaves with poor air circulation were the most severely affected by the disease. Microscopic observations revealed conidiophores branching dichotomically at least five times. Conidiophores ended with sterigmata bearing single conidia. Conidia measured 19 to 24 × 16 to 18 μm and were elliptical to near spherical and hyaline. Oospores were not present. The pathogen was identified as Peronospora arborescens based on the morphological characteristics (2). Pathogenicity was confirmed by inoculating 60-day-old healthy P. nudicaule plants with a conidial suspension (1 × 105 conidia per ml). Five plants were used as replicates. Inoculated and noninoculated plants were maintained in a growth chamber at 15°C and 90 to 95% relative humidity. After 7 to 10 days, typical symptoms of downy mildew developed oninoculated plants. Peronospora arborescens was observed on infected leaves. Noninoculated plants did not show symptoms. To our knowledge, this is the first report of Peronospora arborescens on P. nudicaule in Italy. Peronospora arborescens was previously reported on P. nudicaule and on many other species of Papaver (P. somniferum, P. dubium, P. caucasicum, P. rhoeas, P. setigerum, and P. argemone) in everal countries (1,2). References: (1) P. J. Cotteril and I. G. Pascoe. Australas. Plant Pathol. 27:263, 1998. (2) S. M. Francis. No. 686 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, U.K., 1981.
First Report of Tomato yellow leaf curl virus in Tomato in Guadeloupe
Authors: Urbino C. , Tassius K. 
Published: May 2007

In September 2001, symptoms of stunting and chlorotic curled leaves of reduced size were observed on tomato plants in Guadeloupe. These symptoms were different from those described for Potato yellow mosaic virus, which has been present since 1993, but similar to those described for Tomato yellow leaf curl virus (TYLCV). Samples from symptomatic plants were collected and analyzed by polymerase chain reaction (PCR). Primers PC1 (5′-TGACTATGTCGAAGCGACCAGG-3′) and PC2 (5′-CGACATTACAGCCTCAGACTGG-3′) were designed to amplify a 950-bp fragment within the coat protein gene (CP) of TYLCV-IL species (2). Primer pair MP16/MP82 (3) amplified a 550-bp fragment from the conserved nonanucleotide sequence (TAATATTAC) to the 5′ end of the CP gene. Products of expected sizes were obtained with both pairs of primers from all symptomatic samples but not from uninfected samples. A 950-bp and a 550-bp PCR product were cloned into a pGEM-T Easy Vector (Promega, Madison, WI) and sequenced with plasmid specific primers (SP6 and T7). Sequences were compared with those available in the NCBI database using BlastN. Fifteen of the sequences that gave the highest score with BlastN were aligned with the Guadeloupe sequences using Clustal W. The nucleotide sequence of the 950-bp fragment (GenBank Accession No. AY319645) shared at least 97% sequence identity with that of TYLCV from Israel (EMBL Accession No. X15656), Puerto Rico (GenBank Accession No. AY134494), Cuba (EMBL Accession No. AJ223505), and the Dominican Republic (GenBank Accession No. AF024715). Similar percentages of identity were obtained with the 550-bp sequence (GenBank Accession No. AY319646). These results confirm that a begomovirus belonging to the species TYLCV-Israel is infecting tomato in Guadeloupe. To our knowledge, this is the first report of TYLCV in this region of the Caribbean. Puerto Rico is the closest location from which TYLCV was previously reported (1). In May 2002, typical TYLCV symptoms were observed in all tomato production areas at an incidence of 80 to 100%. References: (1) J. Bird et al. Plant Dis. 85:1028, 2001. (2) Y. Martinez et al. Rev. Prot. Veg. 18:168, 2003. (3) P. Umaharan et al. Phytopathology 88:1262, 1998.