bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Experimental Infection to Investigate the Indirect Transmission of Classical Swine Fever Virus by Excretions of Infected Pigs
Authors: Dewulf J. , Laevens H. , Koenen F. , Mintiens K. , de Kruif A. 
Published: March 2003

SummaryIn this experiment transmission of classical swine fever (CSF) virus via excretions of infected pigs was investigated under experimental conditions. Five pairs of pigs were experimentally infected with CSF virus. Eight days after experimental infection, when all pigs were viraemic for at least 3 days, the pens were depopulated and 20 h later, restocked with five pairs of susceptible pigs which stayed in these pens for 35 days. During the first 3 weeks of the experiment, the pens were neither cleaned nor disinfected. During the observation period, none of the susceptible pigs became infected. This result indicates that CSF virus spread via excretions is of minor importance in the early stages of infection. For extrapolation of these findings to the field situation and to increase the validity of the conclusions further research is needed to evaluate the effect of factors like virus strain, interval, …, that may influence the outcome of the experiment.
Microalgal Communities of the Sea Ice, Ice‐Covered and Ice‐Free Waters of Wood Bay (Ross Sea, Antarctica) During the Austral Summer 1993 – 94
Authors: Moro Isabella , Paccagnella Roberta , Barbante Carlo , Andreoli Carlo 
Published: March 2003

Abstract. During the austral summer 1993 – 94, microalgal density and biomass were investigated in the sea ice, in the underlying water column, in the melt water and during the formation of the sea ice. Of the 96 taxa identified, 59 were diatoms and 32 were dinoflagellates. Among the remaining five species, Pseudopleurochloris antarctica was very abundant both in the sea ice and in the ice‐free waters. Cell densities and biomass of microalgae were higher in the bottom of the sea ice and during the formation of the ice than in the seawater, and diatoms were the dominant group at higher microalgal biomass. Among these, Entomoneis kufferathii, Chaetoceros dichaeta and Fragilariopsis species were the most common taxa.
Case Report. Pathohistological findings in a clinical case of disseminated infection with Fusarium oxysporum
Authors: Peltroche‐Llacsahuanga Heidrun , Manegold Edith , Kroll Gisela , Haase G. 
Published: March 2003

SummaryDespite appropriate antimicrobial and antifungal therapy (amphotericin B), a disseminated infection with Fusarium oxysporum in a 75‐year‐old immunocompromised patient (acute myeloid leukaemia, minimal leucocyte count of 0.5 giga l−1) led rapidly to death. A similarly fatal course of an F. oxysporum infection has been reported in several cases. Fusarium oxysporum could be isolated shortly before death from blood cultures and from a swab taken from skin efflorescences. An autopsy revealed histopathologically typical fungal infiltrates in the mucosa of the pharynx, epiglottis, trachea, and oesophagus and in the parenchyma of the spleen, the lung and both kidneys. Because of the high risk of a fatal outcome of this infection, the clinician should aim at maximum diagnostic enforcement. We propose both analysis of blood cultures and immediate skin biopsy—with PAS‐staining—of suspicious dermal efflorescences for microscopic examination. The treatment of choice is discussed controversially but a beneficial effect has been reported from granulocyte transfusion, subcutaneous administration of GM‐CSF and concomitant treatment with amphotericin B.
Androgenesis from a Lolium multiflorum × Festuca arundinacea hybrid to generate extreme variation for freezing‐tolerance
Authors: Zare A‐G. , Humphreys M. W. , Rogers W. J. , Collin H. A. 
Published: March 2003

AbstractNew opportunities for plant breeding using androgenesis in Lolium × Festuca hybrids have been identified. Plants derived by anther culture from a Lolium multiflorum × Festuca arundinacea (5x) hybrid were screened for freezing‐tolerance, and their post‐freezing recovery compared. The androgenic population showed extreme diversity in freezing‐tolerance. While the majority of androgenic plants had inferior freezing‐tolerance compared with the freezing‐sensitive L. multiflorum parent, 6% of the population were more freezing resistant than the freezing‐tolerant Festuca parent. Novel Lolium and Festuca gene combinations resulting from rare meiotic events were recovered within the androgenic population. The two most freezing‐tolerant androgenic plants carried virtually the entire F. pratensis subgenome of F. arundinacea. F. pratensis is known to carry genes for freezing‐tolerance and would be expected to be the primary source of genes governing this trait within the F. arundinacea genome. The most freezing‐tolerant androgenic plants were more freezing‐tolerant than the hybrid plant from which they were derived. Consequently, androgenesis was also effective in removing factor(s) reducing the expression of freezing‐tolerance within the L. multiflorum × F. arundinacea (5x) hybrid.
Introgression of crown rust resistance from Festuca spp. into Lolium multiflorum
Authors: Oertel C. , Matzk F. 
Published: March 2003

AbstractCrown rust, Puccinia coronata Corda, causes one of the most damaging foliar diseases in Italian ryegrass, Lolium multiflorum Lam. For introgression of crown rust resistance, highly resistant hybrids of the crosses Festuca arundinacea (2n = 6x = 42) ×L. multiflorum (2n = 4x = 28) and reciprocally, L. multiflorum (2n = 2x = 14) ×Festuca pratensis (2n = 4x = 28) and subsequently resistant recombinant individuals were used as female parents and susceptible cultivars of Italian ryegrass as male parents in three successive backcrosses. The BC3 plants were selfed and crossed mutually. Uredospores of seven different crown rust isolates collected from plants of L. multiflorum, Lolium perenne, F. pratensis, F. arundinacea and L. multiflorum × F. pratensis hybrids were applied to identify the resistance or susceptibility of the parental species, backcrossed, selfed and intercrossed progenies. The various crown rust populations revealed a species‐specific capability to infect plants of the Lolium‐Festuca complex corresponding to the host species from which the spores originated. Selected BC9 plants, however, were found to be completely resistant to all crown rust populations tested. Successful introgression of the resistance was achieved from F. arundinacea as well as from F. pratensis. The resistance represents a dominant character, apparently based on a strong heterologous incompatibility between host and pathogen. In phenotype, bivalent formation during meiosis and in fertility, the novel germplasms are comparable with the L. multiflorum cultivars.
Cytogenetic study of Helianthus laevigatus and its F1 and BC1F1 hybrids with cultivated sunflower, Helianthus annuus
Authors: Atlagić J. , Š Korić D. 
Published: March 2003

AbstractAlthough the wild sunflower species Helianthus laevigatus has not been extensively studied it may be considered for sunflower breeding as a potential source of desirable genes for Sclerotinia stalk rot resistance and high contents of proteins and linoleic acid in the seed.A set of six H. laevigatus populations was crossed to cultivated sun~ower lines and produced nine F1 (2‐14 plants) and 66 BC1F1 hybrid combinations (1‐13 plants). Male sterility occurred in F1 and BC1F1 hybrid combinations and pollen viability was lower in the progenies than in the parents (51.6‐77.2%in F1 and in F1 and 4.8‐34.0% in BC1F1). Meiosis was normal in the H. laevigatus populations It was found that this tetraploid species also occurred in a hexaploid form Numerous irregularities were observed in the meiosis of the F1 interspecific hybrids During diakinesis, quadrivalents and hexavalents were recorded in addition to bivalents Dislocated chromosomes and chromosome bridges were present in the other phases The chromosome number in F1 was 68 (tetraploid). Irregularities in chromosome pairing were observed in the interspecific hybrids at BC1F1. There were many univalents, and trivalents quadrivalents and hexavalents were also present The chromosome number in the BC1F1 generation ranged from 34 to 60. The occurrence of meiotic irregularities in the F1 and BC1F1 interspecific hybrids indicates that H. laevigatus and the cultivated sunflower differ in genome constitution.
Race identification in powdery mildew (Sphaerotheca fuliginea) on melon (Cucumis melo) in Japan
Authors: Hosoya K. , Narisawa K. , Pitrat M. , Ezura H. 
Published: March 2003

AbstractPowdery mildew fungi isolated from single lesions on leaves of susceptible melon genotypes during semi‐forcing and late‐raising cultivation in Japan were tested. All 80 of the isolated strains were identified as Sphaerotheca fuliginea. The dominant fungus races found during semiforcing cultivation were race 5 in March (100%) and race 1 in May (100%), and race 1 (80%) during late‐raising cultivation. Although the frequencies were quite low (13% in late August, but no isolation earlier in the season), two new races of S. fuliginea, which could not be identified by the differential genotypes, appeared during late‐raising cultivation. These results suggest that the resistance gene to races 1 and 5 of S. fuliginea should be introduced into the breeding materials in Japan.
Culture of embryos and shoot tips for chromosome doubling in Lolium perenne and sterile hybrids between Lolium and Festuca
Authors: Pašakinskiene I. 
Published: March 2003

AbstractAn improved method is reported for polyploid induction in Lolium (ryegrass), and in sterile F1 hybrids between Lolium and Festuca (fescue). Two factors greatly increased the survival rate of colchicine‐treated embryos of Lolium perenne (perennial ryegrass) germinated and cultured in vitro (1) a high concentration of sucrose (100 g/1) in the germination medium and (1), maintenance at a low temperature of 10°C for 2 weeks after treatment. The maximum success rate for chromosome doubling among survivors of perennial ryegrass was 79.1%, and for L. perenne×Festuca arundinacea F1 hybrid embryos it exceeded 40%. The same doubling treatment also works with shoot tip culture in non‐ flowering genotypes obtained by anther culture of L. multiflorum×F. arundinacea hybrids.
Heritability estimates for winter hardiness in lentil under natural and controlled conditions
Authors: Ali A. , Johnson D. L. 
Published: March 2003

AbstractHeritability analysis for cold tolerance in lentil was conducted using parental, F2 and F3 populations at two locations in Balochistan, Pakistan and one controlled environment in Fort Collins, Colorado, USA. Populations of parental and F2 families were grown over 2 years (1991‐92 and 1992‐93) at Quetta, Balochistan, Pakistan. In 1992‐93, parental and F3 families were studied at Quetta, and Kalat, Balochistan, Pakistan. Evaluation for normality using non‐transformed and log‐transformed data failed. Attempts to use analysis of variance were then abandoned in favour of parent‐offspring regression for narrow‐sense heritability. Estimates of narrow‐sense heritability ranged from 0.31±0.06 to 0.71 ± 0.06 under field conditions. Under controlled conditions, the estimated heritability was maximized at 1.00 ± 0.17 using 6‐ to 8‐week‐old lentils. Significant transgressive segregants were found in five of the six populations in the F3 generation. Transgressive segregants appeared in the controlled F3 generation but were not observed in field environments. This indicates that cold tolerance is under additive gene control and is environmentally sensitive in gene expression.
Genetic control of crossability of triticale with rye
Authors: Guedes‐Pinto H. , Lima‐Brito J. , Ribeiro‐Carvalho C. , Gustafson J. P. , Qualset C. O. 
Published: March 2003

AbstractLimited genetic knowledge is available regarding crossability between hexaploid triticale (2n= 6x= 42, 21″, AABBRR, amphiploid Triticum turgidum L.‐Secale cereale L.) and rye (2n= 14, 7″, RR). Our objectives were to determine (1) the crossability between triticales and rye and (2) the inheritance of crossability between F2 progeny from intertriticale crosses and rye. First, ‘8F/Corgo’, a hexaploid triticale, was crossed as a female with two landrace ryes, ‘Gimonde’ and, ‘Vila Pouca’ and two derived north European cultivars, ‘Pluto’ and ‘Breno’. These crosses produced 21.7, 20.9, 5.9, and 5.6%, seed‐set or crossability, respectively, showing that the landrace ryes produced higher seed‐set than the cultivars. Second, ‘Gimonde’ rye was crossed as a male with four triticales for 3 years. The control cross, ‘Chinese Spring’ wheat × rye, produced 80‐90% seed‐set. Of the four triticales, ‘Beagle’ produced 35.7‐56.8% seed‐set. The other three triticales produced less than 20% seed‐set, showing that the triticales differ in crossability with ‘Gimonde’ rye. Third, six FiS from intertriticale crosses (‘8F/Corgo’×‘Beagle’, ‘Beagle’×‘Cachirulo’, ‘Lasko’×‘Beagle’, ‘8F/Corgo’×‘Cachirulo’, ‘Lasko’×‘Cachirulo’, ‘Lasko’×‘8F/Corgo’) were crossed to ‘Gimonde’ rye. Results indicated that lower crossability trait was partially dominant in the two F1S from crosses involving ‘Beagle’(high crossability) with‘8F/Corgo’ and ‘Cachirulo’(low crossability) and completely dominant in the ‘Beagle’×‘Lasko’ cross, as it happens in wheat. Fourth, segregants in four F2 populations (‘Lasko’×‘Beagle’, ‘8F/Corgo’×‘Beagle’, ‘Lasko’×‘8F/Corgo’, and‘8F/Corgo’×‘Cachirulo’) were crossed with rye. Segregation for crossability was observed, although distinct segregation classes were blurred by environmental and perhaps other factors, such as self‐incompatibility alleles in rye. Segregation patterns showed that ‘Beagle’, with high crossability to rye, carries either Kr1 or Kr2. The three triticales with low crossability with rye were most likely homozygous for Kr1 and Kr2. Therefore, it is likely that the Kr loci from A and B genomes acting in wheat also play a role in triticale × rye crosses.
Rapid introduction of disease resistance from rye into common wheat by anther culture of a 6x triticale × nulli‐tetrasomic wheat
Authors: Zhang X. Q. , Wang X. P. , Ross K. , Hu H. , Gustafson J. P. , Qualset C. O. 
Published: March 2003

AbstractPowdery mildew (caused by Erysiphe graminis) and yellow rust (caused by Puccinia striiformis) are the two most serious wheat diseases found in China. Rye chromosomes, carrying genes for resistance to these diseases, were introduced into common wheat in two generations using chromosome engineering and anther culture. The F1 hybrids from a cross involving a hexaploid triticale (×Triticosecale Wittmack) ×‘Chinese Spring’ nulli‐tetrasomic N6DT6A wheat aneuploid line were anther cultured and doubled‐haploid plants were regenerated. Using genomic in situ hybridization, C‐banding and biochemical marker analyses, one of the anther‐cultured lines (ZH‐1)studied in detail, proved to be a doubled‐haploid with one rye chromosome pair added (1R) and a homozygous 6R/6D substitution (2n= 44). The line was tested for expression of disease resistance and found to be highly resistant to powdery mildew and moderately resistant to yellow rust.
Maternal and embryonal control of seed colour by different Brassica alboglabra chromosomes
Authors: Heneen W. K. , Brismar K. 
Published: March 2003

AbstractMost oilseed rape, Brassica napus, cultivars are black‐seeded. The progenitor species, Brassica rapa, has either yellow or black seeds, while known cultivars of the other progenitor species Brassica oleracea/alboglabra have black seeds. To determine which chromosomes of B. alboglabra are carriers of seed colour genes, B. rapaalboglabra monosomic addition lines were produced from a B. napus resynthesized from yellow‐seeded B. rapa and brown/black‐seeded B. alboglabra. Eight out of nine possible lines have been developed and transmission frequencies of the alien chromosomes were estimated. Three B. alboglabra chromosomes in three of these lines influenced seed colour. B. rapa plants carrying alien chromosome 1 exhibited a maternal control of seed colour and produced only brown seeds, which gave rise to plants with either yellow or brown seeds. However, B. rapa plants carrying alien chromosome 4 or another as yet unidentified alien chromosome exhibited an embryonal control of seed colour and produced a mixture of yellow and brown seeds. The yellow seeds gave rise to yellow‐seeded plants, while the brown seeds gave rise to plants that yielded a mixture of yellow and brown seeds, depending on the absence or presence, respectively, of the B. alboglabra chromosome. Consequently, both maternal and embryonal control of seed colour are expected to contribute to the black‐seeded phenotype of oilseed rape.
Expressed sequence tags from cold‐acclimatized barley can identify novel plant genes
Authors: Faccioli P. , Pecchioni N. , Cattivelli L. , Stanca A. M. , Terzi V. 
Published: March 2003

AbstractExpressed sequence tags (ESTs) databases are being created for several plant species. ESTs have the potential to analyse the expressed part of the genome, and to be used in a wide range of applications from the theoretical aspect of plant biology to the breeding process. The present study is based on a cold‐stressed cDNA library as a source of ESTs in barley: partial cDNA sequencing of randomly isolated clones yielded 960 ESTs. The strategy of random sequencing cDNA clones at their 5’ ends allows one to obtain information on the steady‐state level of the transcripts in a cold‐stressed green leaf of barley. Repetitive sequencing of nearly identical ESTs provides, in addition, useful information on the existence of multigene families. The results of a BLAST search performed on this set of ESTs showed that 18.5% of the tags exhibited no significant homology to known genes, 10% had significant levels of homology with known cold or other stress‐related genes, about 26% proved homologous to enzymes involved in several metabolic pathways and about 15% encoded for ribosomal proteins, cytoskeleton proteins, histones, ubiquitin, elongation factors and others. Redundancy was found for some classes of tag: RuBisCo, cab proteins, carbonic anhydrase, glutamate decarboxylase and stress related proteins.
Detection by simple sequence repeat markers of introgression from Coffea canephora in Coffea arabica cultivars
Authors: Anthony F. , Quiros O. , Topart P. , Bertrand B. , Lashermes P. 
Published: March 2003

AbstractMicrosatellites or simple sequence repeats (SSR) were used to assess polymorphism among 16 Coffea arabica and four Coffea canephora accessions, and to identify DNA introgression fragments from C. canephora in four C. arabica lines. Thirty‐one primer pairs allowed for the identification of 92 polymorphic alleles distributed over 37 loci. The C. arabica accessions derived from the genetic bases ‘Typica’ and ‘Bourbon’ were grouped separately according to their genetic origin. Two genotypes derived from a spontaneous hybrid (C arabica×C. canephora) were classified with the C. canephora accessions from Central Africa. Coffea canephora from West Africa were separated from the other accessions studied. Four alleles related to introgression (i.e. present in C. canephora and introgressed lines, and absent in C. arabica) were identified. The SSR markers were used successfully for characterization of a particular cultivar (‘Veranero’) from Costa Rica, which is known for its late maturity.
Preliminary evaluation of turfgrass (perennial ryegrass and red fescue) cultivars for resistance to red thread disease using artificial infection
Authors: Berestetski A. , Ehrig F. , Kastirr U. 
Published: March 2003

AbstractSelection of main cool‐season turfgrasses (perennial ryegrass and red fescue) for resistance to red thread disease caused by Laetisaria fuciformis has not progressed during the last 30 years because of low reproducibility of experiments carried out under natural infection. In this study, evaluation of a set of the turfgrass cultivars, including non‐host fodder grasses as control, was performed in a climatic chamber, a cold house and in the field using three types of artificial inoculum, and correlations between trials were analysed. In general, cultivars of Festuca rubra were more susceptible to the disease but differentiated better than cultivars of Lolium perenne. Significant interactions between cultivars of L. perenne and F. rubra and isolates of L. fuciformis were found. The fungus was also able to colonize leaves of sow thistle and wheat seedlings. In field conditions and in the glass cold‐house Dactylis glomerata was found to be relatively resistant to red thread disease. A possible selection programme is proposed.
Heritability of in vitro plant regeneration capacity in sunflower
Authors: Nestares G. , Zorzoli R. , Mroginski L. , Picardi L. 
Published: March 2003

AbstractCotyledons from 20 inbred lines of sunflower were evaluated in vitro for their regeneration ability on two culture media supplemented with growth regulators. Plant regeneration by direct organogenesis was observed after 4 weeks. Significant differences among inbred lines were found for the in vitro traits ‘percentage of organogenic explants’,‘percentage of shooting explants’,‘percentage of hypertrophing explants’ and ‘percentage of callusing explants’. The medium effect was significant for all variables. Some in vitro traits displayed significant genotype‐culture medium interaction. Regeneration ability was influenced by culture medium, genotype and their interaction and genetic parameters were estimated taking this interaction into account. Heritability values ranged from 0.74 to 0.45. Strong positive correlations were observed among the organogenesis‐related traits ‘percentage of organogenic explants’, ‘percentage of shooting explants’ and ‘proliferation rate’.
Relationship between Ultrasonographic Assessment of the Corpus Luteum and Plasma Progesterone Concentration during the Oestrous Cycle in Monovular Ewes
Authors: Gonzalez de Bulnes A , Santiago Moreno J , Gomez Brunet A , Lopez Sebastian A 
Published: March 2003

ContentsUltrasonographic observations of the corpus luteum (CL) and collection of blood samples for progesterone radioimmunoassay were performed daily during 15 oestrous cycles in Spanish Merino ewes, a consistently monovular breed. Ultrasonographic image of the CL changed during the oestrous cycle, increasing its echogenic pattern from ovulation to luteolysis. The size of the CL and mean progesterone levels were significantly affected by day of cycle (p < 0.05 and p < 0.001, respectively). Both increased their values from day 1 to day 12 (from 49.6 ± 7.4 to 154.6 ± 11.8 mm2 and from 0.2 ± 0.0 to 2.8 ± 0.5 ng/ml, respectively) and then declined sharply until day 0 (28.2 ± 5.3 mm2 and 0.1 ± 0.0 ng/ml, respectively). There was a significant correlation between CL area and plasma progesterone concentrations during the entire oestrous cycle, taking the developing and regressing phases of the CL separately (p < 0.05). A central cavity was observed in 33.3% of the CL studied. The presence of this cavity had no effect in total luteal‐tissue area of the CL nor on oestrous cycle length or on progesterone concentrations. Likewise, the cavity did not affect the correlations observed between CL size and progesterone levels, CL size and day of cycle and progesterone levels and day of cycle. It is concluded that ultrasonographic assessment of CL area is a reliable method for estimating peripheral plasma progesterone levels, regardless to the presence or absence of a cavity in the CL.