bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Mixed Infection of Rabbits with Yersinia enterocolitica and Listeria monocytogenes
Authors: NAJDENSKI H. , VESSELINOVA A.
Published: March 2003

Experimental mixed infection was reproduced in rabbits after per os infection with Yersinia enterocolitica serotype 0:3 cells. Four days later some of animals were re‐infected orally with Listeria monocytogenes serotype 4b cells. A third group of healthy rabbits was also infected per os with Listeria monocytogenes. The infectious process was followed dynamically from days 1–28.

The experimental animals were examined for clinical, paraclinical and morphological findings. Augmentation of body temperature and alveolar macrophage number, a decreased number of peritoneal macrophages, leucopenia as well as purulent meningoencephalitis, catarrhal pneumonia, lienitis, lymphadenitis and enteritis were detected after experimental mixed infection. Both types of macrophages demonstrated a weak bactericidal activity against Yersinia enterocolitica and a highly expressed killing effect against Listeria monocytogenes. Yersinia and Listeria cells were isolated from the viscera and brain. Both species of bacteria were established intracellularly in the macrophages by electron‐microscopic examination.

The data received showed that mixed Yersinia enterocolitica 0:3 and Listeria monocytogenes 4b infection of rabbits runs with transitory hyperthermia as a generalized infection and is similar to the Listeria mono‐infection. The immunosuppressive effect induced by oral Yersinia enterocolitica infection of rabbits promotes the expression of listerious agents.
Doxycycline Toxicity in Calves in Two Feedlots
Authors: Yeruham I. , Perl S. , Sharony D. , Vishinisky Y.
Published: March 2003

Doxycycline toxicity caused by a large overdose (10 times the therapeutic dosage) in two feedlots is described. The clinical symptoms occurred after 2–3 days and mortality 5 days after the onset of the medication which was added to the milk replacement.

Mortality reached 25% (five calves) and 27% (seven calves) in herds A and B, respectively.

Pathological and histological findings revealed pulmonary oedema, myocardial degeneration and necrosis. These findings confirm the cardiovascular toxicity, caused apparently by doxycycline administration to the calves, and indicate the potential side‐effects of this drug in cattle.
Polychaete Assemblages in the San José Gulf (Chubut, Argentina), in Relation to Abiotic and Biotic Factors
Authors: Pastor de Ward Catalina T.
Published: March 2003

Abstract. The composition and distribution of the polychaete assemblages of the San José Gulf (Chubut, Argentina) are described in relation to environmental variables using indicator species (TWINSPAN) and canonical correspondence analysis (CCA). The polychaetes were collected during a benthic cruise in October 1984. Sediments were collected at 110 sampling sites using a 0.25 m2 van Veen bottom grab or by divers in near‐shore areas and sieved with 1 mm mesh. A total of 73 polychaete taxa were collected and identified. Both analyses revealed the presence of four main assemblages distributed according to depth as well as bivalve and seaweed abundance gradients: ‘Syllis‐Eunice’ and ‘Harmothoe‐Eunice’ assemblages occurred at the same depths (0 –­ 185 m) and substrata (poorly sorted rock and coarse sand), but were separated by bivalve and seaweed abundance, wherby the highest abundances of bivalves and the minimum abundances of seaweeds corresponded to the ‘Syllis‐Eunice’ association. The ‘Ninoe‐Glycera’ and ‘Aglaophamus‐Fabriciinae indet. 6’ assemblages also occurred at similar depths (0 – 60 m) and substrata (very well‐sorted medium‐fine sand), but differed in their composition of bivalves and seaweed abundances; the ‘Aglaophamus‐ Fabriciinae indet. 6’ association corresponded with minimum bivalve and maximum seaweed abundances.
Does Change in an Adriatic ­Hydromedusan Fauna Indicate  an Early Phase of  Marine Ecosystem Destruction?
Authors: Benović Adam , Lučić Davor , Onofri Vladimir
Published: March 2003

Abstract. One of the most critical problems in human efforts to combat consequences of pollution is the proper identification of the initial phases of ecosystem disturbance. Investigation of hydrographic conditions and medusan species composition in the Northern Adriatic region from 1992 to 1997 showed persistence of hypoxic conditions and low numbers of meroplanktonic hydromedusae. The changes observed in the hydromedusan fauna demonstrate one aspect of the long‐term consequences of oxygen deficiencies in marine ecosystems: decreased biodiversity. We suggest that the species composition of meroplanktonic hydromedusae may be a useful indicator of the early phase of such changes.
Tintinnids (Ciliophora) and Other  Net Microzooplankton (> 30 µm) in Southwestern Atlantic Shelf Break Waters
Authors: Thompson Gustavo A. , Alder Viviana A. , Boltovskoy Demetrio
Published: March 2003

Abstract. Proportions of foraminifers, tintinnids, polycystine radiolarians, pteropods and crustacean larval stages were estimated in a collection of 76 vertically stratified (0 – 100 m) 30 µm net microplankton samples from 16 stations along the Argentine shelf‐slope (around 200 m isobath – between 40 and 56° S), covered on 13 – 18 November 1996. Tintinnids were identified to species. Relative abundances of the microzooplankton assessed and chlorophyll a values allow to define two contrasting groups of stations: ‘deep’ and ‘shallow’. The former, located in pelagic, purely subantarctic Malvinas Current waters, hosted higher proportions of foraminifers and lower proportions of tintinnids, as well as less chlorophyll a (all differences were significant at the 0.1 % level). ‘Shallow’ stations were located in the area of the thermohaline front where the Patagonian Current comes in contact with the Malvinas Current, and were generally characterized by higher chlorophyll a levels (up to 3.7 µg Chl a · l–1). The distribution of tintinnid species, on the other hand, allowed no discrimination between these two areas, although some of the dominant forms showed much higher relative abundances in one of the two groups of stations. Twenty‐six tintinnid taxa were recorded, yet only 6 accounted for 95 % of the specimens identified. Tintinnid taxocoenoses were characterized by a few abundant species and many rare ones. Numbers of tintinnid species and specific diversity did not differ noticeably with depth and latitude. Cape Horn Current waters were detected in the area by the presence of expatriated organisms presumably originating at mid‐latitudes in the South Pacific Ocean.
Variation in the Sizes of Chthamalid ­Barnacle Post‐Settlement Cyprids on European Shores
Authors: O'Riordan Ruth M. , Delany Jane , McGrath David , Myers Alan A. , Marie Power Anne , Ramsay Neil F. , Alvarez Damaso , Cruz Teresa , Pannacciulli Federica G. , Range Pedro , Relini Giulio
Published: March 2003

Abstract. As part of a wider study on the settlement and recruitment of Chthamalus spp. in Europe, this study investigated whether chthamalid cyprids can be separated by length on a European scale. Variation in cyprid length with latitude and temporal variation at selected localities were also examined. The lengths of cyprids collected between 1996 – 1999 on nine rocky shores in Europe are reported. Elminius modestus cyprids were found only at Roscoff, NW France and could be distinguished due to their carapace shape and length. They showed a unimodal length distribution, measuring between 450 and 625 µm, with no variation in length between the two sampling dates (1997 and 1998). Based on carapace shape and length, the remaining cyprids in the collections were identified as one of three chthamalid species, Chthamalus montagui, Chthamalus stellatus or Euraphia depressa. Bimodal length distributions of chthamalid cyprids were seen on some shores, while others had a single small‐sized modal group (representing C. montagui on Atlantic shores and/or E. depressa in the Mediterranean) separated from a few distinctly larger cyprids (C. stellatus). Metamorphs collected simultaneously with cyprid collections were identified as C. stellatus or C. montagui, except at Roscoff, where E. modestus were also found. In southern Portugal, where all metamorphs collected were C. montagui and adult C. montagui were the dominant barnacles, most cyprids measured between 350 and 550 µm long and this size distribution coincides with the distribution expected for C. montagui. Cyprids collected on these four more southerly Portuguese shores had the same modal length class (475 µm) and this remained constant between successive years at Luz and Albufeira, Algarve. The smallest (350 µm long) wild chthamalid cyprids found were from southern Portugal and Italy. In Spain, France and Ireland the smallest chthamalid cyprid was 425 µm long. The results from the present study support the hypothesis that on Atlantic shores cyprids of C. montagui can be separated from those of C. stellatus based on size, although there is some variation in cyprid length with latitude as well as temporal variation at selected localities.
Species‐specific primers of chitin synthase 1 gene for the differentiation of the Trichophyton mentagrophytes complex
Authors: Kano R. , Nakamura Y. , Watari T. , Watanabe S. , Takahashi H. , Tsujimoto H. , Hasegawa A.
Published: March 2003

Species‐specific primers were designed from nucleotide sequences of the chitin synthase 1 gene (CHS1) of Arthrodermabenhamiae, A. simii and A. vanbreuseghemii. The A. benhamiae‐specific primer amplified a 560‐bp fragment from A. benhamiae but not from A. simii and A. vanbreuseghemii. The A. simii‐specific primers amplified a 470‐bp fragment from A. simii but not from A. benhamiae and A. vanbreuseghemii. The A. vanbreuseghemii‐specific primers amplified a 360‐bp fragment from A. vanbreuseghemii but not from A. benhamiae and A. simii. With these species‐specific primers of CHS1 genes, 10 clinical isolates from humans and animals were examined by polymerase chain reaction analyses. These isolates proved to be identical to A. vanbreuseghemii.
Fungal flora in house dust in Riyadh, Saudi Arabia
Authors: Bahkali  , Parvez
Published: March 2003

Fungi in the house‐dust of houses in the less populated and densely populated areas of Riyadh, Saudi Arabia, were screened. The screened area included drawing rooms, living rooms, kitchens, bedrooms and bathrooms. A total of 74 fungal species were isolated. The highest number of fungal colonies were found in the living rooms followed by bedrooms. The number of fungal colonies isolated were higher in densely populated areas compared with less populated areas. Aspergillus was the predominant genus represented by highest number of species followed by Penicillium.
Studies of the influence of ochratoxin A on immune and defence reactions in weaners
Authors: Müller G. , Kielstein P. , Rosner H. , Berndt Angela , Heller M. , Köhler Heike
Published: March 2003

Even in subtoxic amounts, the mycotoxin, ochratoxin A, produced immunomodulation in weaner pigs in a dose‐dependent mode. In addition to increased counts of total leukocytes and neutrophils in the blood, reduced lymphocyte levels were observed. There was a striking increase in the counts of eosinophils and of apoptotic phagocytes. Functionally, there was a predominance of the production of reactive oxygen radicals in whole blood, reduced phagocytosis performance and reduced expression of a swine‐specific surface marker (SWC1) on lymphocytes. In a few single experiments, clinical manifestations could be demonstrated. Lung clearance and the degree of severity of experimental pneumonia as well as cutaneous hypersensitization may be influenced by ochratoxin A.
Isolation of dermatophytes and other keratinophilic fungi from soils of Mysore (India)
Authors: Deshmukh  , Agrawal  , Jain
Published: March 2003

In Mysore, India, 88 soil samples were collected from various areas and habitats and screened for the presence of dermatophytes and related keratinophilic fungi.
Scopulariopsis brevicaulis: a keratinophilic or a keratinolytic fungus?
Authors: Filipello Marchisio V. , Fusconi A. , Querio F. L.
Published: March 2003

The morphologic expression of human hair and nail invasionin vitrobyScopulariopsis brevicaulisisolates was studied by light microscopy on whole material and on semi‐thin sections, and also by scanning and transmission electron microscopy. Only three isolates of the nine that were examined were keratinolytic, capable of both attacking keratinic substrates and demolishing their keratin. The process showed all the characteristic of enzymatic digestion and was in agreement with the biochemical and morphogenetic scheme proposed for other keratinolytic fungi during their invasion of human hairin vitro. All the active isolates were capable of developing structures related to surface erosion and radial penetration contemporaneously. However the extent and rate of keratinolysis were rather low when compared with the efficiency of other keratinolytic fungi. This finding suggests thatS. brevicaulisis of secondary importance in the mineralization of keratinic substrates in natural environments. From the medical standpoint the mere demonstration of keratinolytic activity means that it may be regarded as a real cause of primary infection.
Extrusion of fluorescein diacetate by multidrug‐resistant Candida albicans
Authors: Yang H.‐C. , Mikami Y. , Imai T. , Taguchi H. , Nishimura K. , Miyaji M. , Moretti Branchini Maia Luisa
Published: March 2003

Summary. Over‐expression of multidrug efflux transporters causes Candida albicans cells to be resistant to azole antifungal agents. There are several kinds of indicator for multidrug resistance (MDR) phenotype of higher eukaryotic cells. Calcein AM is a prefluorochrome that is known as a substrate for multidrug efflux transporters of mammalian cells. We investigated whether calcein AM was also extruded by the ATP‐dependent multidrug transporter (cdr1p) of C. albicans. There was no significant difference in the accumulation of calcein AM between MDR cells and drug‐susceptible cells of C. albicans even with sodium azide, suggesting that calcein AM may not be associated with the CDR1‐gene‐related multidrug efflux system of C. albicans. However, a structurally related prefluorochrome derivative, fluorescein diacetate (FDA), was shown to be extruded by the CDR1 mRNA‐overexpressing yeast cells. In comparison with drug‐susceptible cells, the resistant cells emitted very weak fluorescence when stained with FDA. Furthermore sodium azide increased the fluorescence of the resistant cells more than 20 times, whereas the fluorescence in the drug‐susceptible cells with FDA and sodium azide was three to four times stronger. These results suggested that FDA might be extruded by the CDR1‐related multidrug efflux transporter of C. albicans.
Paracoccidioides brasiliensis: virulence and an attempt to induce the dimorphic process with fetal calf serum
Authors: De Moraes Borba C. , Schäffer G. M. V.
Published: March 2003

Summary.  The virulence of Paracoccidioides brasiliensis strains and the induction of the dimorphic process of the fungus were investigated. The strains were kept under mineral oil for different periods of time, except for one that was successively subcultured on agar slants. Four strains with transitional morphology at room temperature were avirulent to experimental animals. Two strains with typical morphology at 36 °C, one of them preserved under mineral oil for 16 years and the other maintained by successive subcultures for 10 years, were virulent to mice. These strains caused macro‐ and microscopic lesions in various organs, with enlargement of the spleen and heart. An attempt to induce the dimorphic process with fetal calf serum (FCS) in P.brasiliensis strains with transitional morphology failed. FCS was probably unable to stimulate the synthesis of Y cell wall α‐1,3‐glucan. The results demonstrate that keeping strains under mineral oil for a long period of time may have altered the enzymatic activities of the proteinases and other virulence factors that participate in the transition process and in pathogenesis.
Case Reports. Tinea capitis due to Trichophyton soudanense and Trichophyton schoenleinii
Authors: Romano Clara , De Aloe G. , Calcaterra R. , Gianni C.
Published: March 2003

Summary.  Four cases of tinea capitis, two due to Trichophyton soudanense in Italian children who had had contact with Africans, and two due to Trichophyton schoenleinii in an African and an Italian child, respectively, are reported. Infections caused by anthropophilic dermatophytes are rare in Italy and are related to immigration. The most frequent agents of tinea capitis in Italy are zoophilic dermatophytes.
Abundance, polymorphism and genetic mapping of microsatellites in oilseed rape (Brassica napus L.)
Authors: Uzunova M. I. , Ecke W.
Published: March 2003

The objective of the present study was to estimate the abundance and degree of polymorphism of simple sequence repeat (SSR) markers in rapeseed. By screening about 45000 clones of a small inserts library of rapeseed total DNA the abundances of GA/TC and CA/TG simple sequence repeats in the rapeseed genome were estimated to be approximately one repeat every 100 kb and 400 kb, respectively. After sequencing 13 positive clones, primer pairs could be designed for 11 microsatellite loci. Seven of these primer pairs produced reproducible amplification products in a set of 31 rapeseed genotypes, with one pair amplifying two independent products, giving a total of eight amplified loci. The different microsatellite loci displayed between one and three visible alleles. At four loci, additional null alleles were observed. With up to four alleles, polymorphic microsatellite markers show significantly higher allele numbers in rapeseed than restriction fragment length polymorphism (RFLP) markers. Four of the eight microsatellite markers could be mapped on four different linkage groups of an RFLP map of the rapeseed genome.
AFLP fingerprinting in Medicago spp.: Its development and application in linkage mapping
Authors: Barcaccia G. , Albertini E. , Tavoletti S. , Falcinelli M. , Veronesi F.
Published: March 2003

Cultivated alfalfa (Medicago sativa L., 2n= 4x= 32) is one of the most important forage crops in temperate climates. The genus Medicago includes diploid species that are a valuable source of wild germplasm for studying the reproductive system of alfalfa and its abnormalities. A linkage map of an apomeiotic mutant of Medicago falcata (L.) Arcang. (2n= 2x= 16) that spanned 368.6 cM and included 29 amplified fragment length polymorphism (AFLP), 35 random amplified polymorphic DNA (RAPD) and three restriction fragment length polymorphism (RFLP) loci was constructed using a one‐way pseudo‐testcross mapping strategy. The success of such a strategy depends on the presence of sufficiently high levels of heterozygosity in the individual plant which is being mapped and on the informativeness of the marker system that is used. In general: (1) highly informative and reproducible RAPD and AFLP fingerprints were generated and several genome‐specific primers selected; (2) of 67 marker loci mapped, 51 were arranged in 11 main linkage groups and eight additional couples of linked marker loci were detected; (3) mapping of an F1 population theoretically allowed a better estimation of linkage distances since it avoided segregation distortion (x2 analyses revealed segregation distortion in only 5.2% of marker loci); (4) the high frequency of unlinked marker loci obtained suggests that, in this alfalfa genotype, DNA markers are distributed throughout the genome. This type of genetic map should find application and prove useful in marker‐assisted selection and map‐based breeding programmes in meiotic mutants of alfalfa for which there is a lack of suitable genetic markers.
Resistance to powdery mildew in selections from Tunisian landraces of barley
Authors: Czembor J. H. , Johnston M. R.
Published: March 2003

Two‐hundred and thirty‐two accessions of barley landraces collected from Tunisia were screened for resistance to powdery mildew. A number of race‐specific genes were detected using the detached leaf technique. Among the 232 accessions tested, 169 were susceptible to powdery mildew, 20 were resistant and 43 showed differential reactions to the three isolates of powdery mildew used. An attempt was made to determine the number of genes, the types of gene, the types of gene action and the gene loci in 20 resistant accessions. Three types of cross were made: (1) the accessions were crossed to the susceptible variety ‘Pallas’, (2) the accessions were crossed with ‘Pallas’ isolines, and (2) accessions with identical powdery mildew reaction patterns were intercrossed. Three isolates of Erysiphe graminis f. sp. hordei were used: Bzm‐1, KM 18‐75, R13C. A number of different resistance genes were detected among the 19 resistant accessions. Surprisingly, segregation indicating single genes only were detected with the isolates used. Some of these genes could be associated with loci already known. In 19 cases a dominant and in one a recessive mode of inheritance was detected. The recessive gene was not located at the mlo locus. This investigation represents the first systematic study of race‐specific genes for powdery mildew resistance in Tunisian landraces. The newly identified sources of resistance may be used in many strategies of breeding for disease resistance.
Effects of preharvest sprouting on the genetic structure of durum wheat ‘landraces’
Authors: Masi P. , Spagnoletti Zeuli P. L.
Published: March 2003

Preharvest sprouting that occurs in wheat might affect seed viability and cause genetic erosion during periodical rejuvenation of durum wheat accessions in a gene bank. Two durum wheat landraces (MG 7713 and MG 7805) that had been rejuvenated for several years and did show a high percentage of presprouted seeds in the lot from the fourth rejuvenation cycle were identified. The frequency of durum and bread wheat genotypes and the distribution of the two species in three seed classes (ungerminated seeds, seeds with swollen embryo and germinated seeds) were studied. The modified phenol test was used to identify durum and bread wheat seeds and the genotypic frequencies within each species were assessed on the basis of acid polyacrylamide gel electrophoretic patterns of gliadin storage proteins. In these two landraces, durum wheat was more susceptible to preharvest sprouting than bread wheat and the frequency of bread wheat seeds significantly increased over the three rejuvenation cycles examined. Despite this, preharvest sprouting did not cause significant changes in the genotypic frequencies observed within species or loss of some genotypes that could not be attributed to susceptibility to sprouting.
Heterogeneity of random amplified polymorphic DNA sequences in individual seedlings and bulked samples of four cultivars of Brassica napus
Authors: Mailer R. J. , May C. E.
Published: March 2003

Using four different random amplified polymorphic DNA (RAPD) primers, a qualitative and quantitative assessment was made of the level of DNA sequence heterogeneity present in the seedlings of four representative Australian rapeseed cultivars. It was found that, depending upon the primer/cultivar combination, the seedlings diverged from total homogeneity to almost complete heterogeneity. The increase or decrease of sample‐specific RAPD sequences was evaluated in proportional mixtures of DNA from individual seedlings. These results were then compared with those obtained from bulked DNA samples containing DNA from all the seedlings of a cultivar. From these comparisons, it was found that for a specific RAPD to be detectable in a bulked sample, the particular polymorphism had to be present in at least 15% of the individual seedlings. Even so, the bulked samples produced cultivar‐specific RAPD banding patterns with all four primers, showing that any of these primers could be used to identify the different rapeseed cultivars. In contrast to the cultivars ‘Oscar’, ‘Dunkeld’ and ‘Narendra’, the cultivar ‘Rainbow’ was found to be highly heterogeneous—as shown by a diversity of RAPD combinations rather than the presence of differing length RAPDs—and it is suggested that this heterogeneity may be related to the improved tolerance of this cultivar to blackleg infection.
Inheritance of grain filling duration in spring wheat
Authors: Przulj N. , Mladenov N.
Published: March 2003

The genetic basis of grain‐filling duration (GFD, days from anthesis to maturity) in six spring wheat hybrids involving nine varieties (‘Son‐alika’/‘Bobwhite’, ‘Sonalika’/‘Glennson 70’, ‘Lelija’/‘Bobwhite’, ‘Lelija’/‘Mitacore’, ‘Buckbuck’/‘Dugoklasa’, and ‘Vesna’/‘Raduśa’) and their F1, F2, BC1, and BC2 generations was studied in the field near Sarajevo, Yugoslavia. Parental means differed in four of the six crosses. Generation mean analyses of genetic effects indicated that an additive‐dominance model was sufficient for only two crosses: Lel/Bow and Lel/Mco. One or more types of epistasis were significant in the remaining crosses. The F1 and F2 means were either intermediate, closer to the mean of the parent with the longer GFD, or closer to the mean of the Parent with the shorter GFD. Even though different modes of gene action controlled GFD among the six crosses, the heritabilities were reasonably high (narrow sense, 39‐59) range for six crosses), indicating that progress could be made from selection in these crosses for either long or short GFD. The parents were selected to have a range in days from planting to anthesis and to maturity. The relationship between dates of anthesis or maturity and GFD was not consistent, but the two latest‐maturing varieties had the longest GFD, indicating that anthesis or maturity dates are not a good criteria for choosing parents for modifying GFD. Additive genetic effects predominated in the crosses studied here, but epistasis involving dominance gene action was sufficiently important. To eliminate confounding epistatic dominance effects and to take advantage of favourable additive × additive effects during selection for GFD, a breeding strategy involving rapid approach to homozygosity followed by selection after the achievement of homozygosity was suggested.
Heritability of oil content and the onset of flowering in a population of Dimorphotheca pluvialis
Authors: Hof L. , Nieboer I. G. , Dolstra O.
Published: March 2003

To develop efficient breeding strategies for the improvement of oil content and onset of flowering in Dimorphotheca pluvialis, narrow‐sense heritabilities of these characters were estimated. Forty plant progenies were tested in 2 years and heritabilities were estimated from parent‐offspring regression as well as from half‐sib family variance components analyses. For oil content, the heritabilities estimated by means of parent‐offspring regression were 0.36 and 0.33 for 1993 and 1994, respectively. The heritabilities obtained from the variance components analyses were 0.41 and 0.23 for the two years. Heritability estimates for onset of flowering showed more variation. From parent‐offspring regression, the heritabilities were 0.72 and 0.37, and from variance component analysis the estimates were 0.53 and 0.19 for 1993 and 1994, respectively. The obtained heritability values and realized responses suggest that particularly in early selection generations, even with mass selection, considerable progress can be expected. Since correlation studies revealed neither phenotypic nor genotypic correlation between oil content and onset of flowering, selection for both characters can be undertaken independently.
The use of low molecular weight glutenin subunits to distinguish between wheat cultivars with and without resistance to the Russian wheat aphid, Diuraphis noxia
Authors: Labuschagne M. , Maartens H. , Weber W. E.
Published: March 2003

A number of resistance sources for the Russian wheat aphid have been reported in the last few years and were used to develop resistant cultivars from current commercial cultivars in various breeding programmes. It can be diffcult to distinguish between the cultivars with and without resistance without actual infestation and so in this study we looked at low molecular weight glutenin subunits (LMW‐GS) of the two groups. Distinctly different banding patterns were found for the cultivars tested and their isogenic counterparts. Although the LMW‐GS and DN1 and DN5 are coded on different chromosomes, the LMW‐GS are highly repeatable and banding profiles of each cultivar can be used for the identification of unknown seed.
Novel complementary genes for adult plant leaf rust resistance in a wheat stock carrying the 1BL‐1RS translocation
Authors: Sawhney R. N. , Sharma J. B.
Published: March 2003

The wheat‐rye translocation (IBL‐IRS) that carries the tightly linked genes Lr26/Sr31/Yr9, has been widely exploited in the development of wheat cultivars worldwide. This resistance, however, has become ineffective owing to the evolution of new pathotypes of Puccinia recondita that neutralize the resistance of Lr26. Inheritance studies on ‘Federation4′/‘Kavkaz’ revealed complementary genes derived separately from ‘Federation’ and ‘Kavkaz’ for adult plant resistance. This previously undescribed source of resistance appears to be widely effective and could therefore be used to broaden the genetic base for resistance in India. Its effectiveness in other geographical areas is unknown.
Chromosomal localization of five mutant genes in rice, Oryza sativa, using primary trisomics
Authors: Sanchez A. C. , Khush G. S.
Published: March 2003

The chromosomal locations of five mutant genes in rice were determined by crossing the marker stocks with the 12 primary trisomics. Genetic segregation of each gene was studied in the F2 or backcross populations. Out of the 60 possible cross combinations, 43 F2 or BC1 populations were studied. Segregation data indicated that spl11 was located on chromosome 12 while wp2 and eg2(t) were located on chromosome 6. The genes v12(t) and Bc6 were located on chromosomes 8 and 9, respectively, which are sparsely populated with genetic markers.
Mapping of powdery mildew and leaf rust resistance genes on the wheat‐rye translocated chromosome T1BL·1RS using molecular and biochemical markers
Authors: Hsam S. L. K. , Mohler V. , Hartl L. , Wenzel G. , Zeller F. J.
Published: March 2003

Powdery mildew and leaf rust resistance genes on the 1RS arm of the T1BL·1RS translocated chromosome were mapped in relation to the Sec‐1 locus and AFLP and restriction fragment length polymorphism markers, respectively, employing segregating F3 populations. Integration of molecular markers indicated that Pm17 lies between the Lr26 and Sec‐1 loci, with both resistance genes allocated distally to the Sec‐1 locus in the satellite of the 1RS arm.
Ovule dichotomy per locule of the trilocular pistil in cassava, Manihot esculenta: a useful abnormality for increased seed production?
Authors: Ogburia M. N. , Adachi T. , Yabuya T.
Published: March 2003

Histologically, the cassava pistil is trilocular with a single ovule in each locule producing a maximum of three seeds in nature. Heat stress (35°/45°C, night/day temperatures), as a physical treatment was attempted to induce useful reproductive and vegetative traits in 10 F1 hybrids derived from ‘OMR 36‐41’and ‘OMR 36‐42’crosses, and two Asian cassava cultivars,‘Rayong 60’and ‘Rayong 1′, under greenhouse and field conditions. Cytoembryological examination of the repro‐ ductive organs revealed morpho‐structural features of normal pistil in all clones except ‘Rayong 1’which exhibited reproductive variations under greenhouse culture. Genetically, an important variation was ovule dichotomy per locule of the trilocular pistil so that each pistil contained six instead of the usual three ovules and lacked any outer integument. These ovules possessed functional embryo sacs with varying nuclear number. A pair of the dichotomous ovules possessed two embryo sacs of apparent different megaspore mother cells. Vegetatively, F1 hybrids were dwarf (0.50m) in their phenotype and flowered 1 month earlier than the 1.5‐2.0m tall cultivars under greenhouse conditions.
Yield of doubled haploid lines of Nordic spring barley infected with net blotch, Pyrenophora teres
Authors: ROBINSON J.
Published: March 2003

Five Nordic spring barley lines (‘Rolfi’, ‘Arve’, ‘Botnia’, ‘Pohto’ and WW7977) and doubled haploid (DH) populations from a half diallel of crosses between them, were sown in the field in Finland over 2 years and were artificially infected with Pyrenophora teres, the causal agent of net blotch. The purpose of the experiments was to determine the extent of yield loss under net blotch infection in a range of parent barleys and DH populations differing in symptom expression. Analysis of foliar damage symptoms, yield and aerial biomass data indicated that, in both years, there were statistically significant differences among parents and crosses, but the relationships between symptom expression and yield maintenance and between symptom expression and aerial biomass maintenance were stronger in 1997, when yields were higher and net blotch was less severe.
Identification of restorers and maintainers for developing basmati and non‐basmati hybrids in rice, Oryza sativa
Authors: Sarial A. K. , Singh V. P.
Published: March 2003

Twenty‐seven improved aromatic lines of germplasm and 18 non‐aromatic disease‐resistant genotypes of rice were test‐crossed with four cytoplasmic male‐sterile lines (IR 58025A, IR 62829A, PMS 3A and PMS 10A). Thirteen aromatic and 10 non‐aromatic genotypes were selected based on pollen fertility, and crosses were repeated to confirm sterility‐maintaining and fertility‐restoring ability. Genotypes were categorized as effective restorers (> 80% spikelet fertility), partial restorers (21‐79% spikelet fertility) and maintainers (< 1% spikelet fertility). The effective basmati restorers identified were Basmati 385, Chandan, P1031‐8‐5‐1, HKR 241‐IET‐12020, SAF Khalsa 7 and Karnal Local. The basmati maintainers identified were Basmati 370, Pusa basmati 1, P615‐K‐167‐13 and P1173‐4‐1. The frequency of restorers obtained was higher for the non‐aromatic than the aromatic basmati type. The performance of restorers varied with cytoplasmic male‐sterile (CMS) line, location and season of testing. The differential ability to restore fertility in the CMS lines that have the wild abortive (WA) cytosterile system could result from different nuclear backgrounds of the CMS lines. These restorers and maintainers possess acceptable grain dimensions, a desirable degree of aroma, volume expansion through linear kernel elongation and cooking quality characteristics of basmati rice. These genotypes will contribute to developing basmati hybrids and provide restorers and maintainers with acceptable key basmati quality characteristics.
A temporal genetic analysis of disease resistance genes: resistance to melon vine decline derived fromCucumis melovar.agrestis
Authors: Iglesias A. , Picó B. , Nuez F.
Published: March 2003

Melon vine decline causes severe economic losses to melon crops all over the world. Two fungi.Acremonium cucurbitacearumandMonosporascus cannonballus, have been reported as the main causal agents of root damage, responsible for the decrease in root water and nutrient uptake capacity. However, melon vine decline aetiology is not completely understood, so screening assays must be conducted under natural infestation conditions. In field assays, the erratic effect of uncontrolled environmental factors makes the study of the trait's genetics difficult. The percentage of asymptomatic plants scored at individual moments during the infection process in the field is an imprecise indicator of the resistance level of each genotype. The analysis of disease progress curves does allow for the minimization of the stochastic fluctuations caused by environmental factors at various moments in time. Using this analysis the mode of inheritance of the partial resistance to melon vine decline derived from the accession Pat 81 ofCucumis melovar.agrestiswas further studied. Data from the six generations assayed (susceptible and resistant parents. F1, F2, and backcrosses BC1and BC2were fitted to an additive/dominance model without epistatic effects using a scaling test. Monogenic control was proposed as the simplest model to explain the data. Assuming this simple model, the method of analysis also allowed for the characterization of the incomplete penetrance of resistance, which varies as a log probit function of the time. Simple genetic control would simplify the use of Pat 81 in breeding programmes aimed at developing commercial melon varieties with resistance to vine decline.
Gamma ray‐induced genetic manipulations in flower colour and shape in Dendranthema grandiflorum and their management through tissue culture
Authors: Datta S. K. , Chakrabarty D. , Mandal A. K. A.
Published: March 2003

Rooted cuttings of Dendranthema grandiflorum cv. ‘Puja’ were treated with different doses of gamma rays. Sectorial somatic mutations both in flower colour and shape were detected in all the doses. The original floret colour of ‘Puja’ is red‐purple and florets are flat spoon shaped. One of the mutant floret colour was yellow‐orange with original flat florets and another mutant floret colour was yellow‐orange with tubular florets. Original and mutated ray florets were cultured on agar‐solidified Murashige and Skoog basal medium supplemented with sucrose and different combinations of 1‐naphthaleneacetic acid (NAA) and 6‐benzylaminopurine (BAP). Direct shoot organogenesis was seen within 2 weeks of culture initiation. The best regeneration was obtained on medium supplemented with 1 mg/l BAP + 0.5 mg/l NAA. Shoots regenerated from all explant types were rooted in vitro and transferred to the field. Regenerated plants flowered true‐to‐explant floret colour and shape. The isolated yellow floret colour mutants and yellow floret colour mutants with tubular florets were maintained vegetatively and have proved to be true to type in two successive generations.
Introduction of aromatic fragrance into cultivated tomato from the peruvianum complex'
Authors: Kamal H. M. , Takashina T. , Egashira H. , Satoh H. , Imanishi S.
Published: March 2003

This study was performed to introduce the distinct aromatic fragrance of Lycopersicon peruvianum LA 1554 into the cultivated tomato, Lycopersicon esculentum. The strong breeding barriers existing between these two distantly related species were circumvented by the ovule selection and culture method. A large BC1F1 population was developed and among 127 plants, 36 were self‐compatible and yielded fruits. Fruits of some of these selected plants were found to be enriched with a sweet aromatic flavour. Sensory evaluation of the fruit aroma of these selected plants was performed by a panel of 12 members against one of the best consumer‐rated Japanese commercial tomato cultivars, ‘Momotaro’. Although extensive variation was observed in fruit‐aroma in the BC1F1 population, panel opinion on ‘flavour‐desirability’ significantly favoured the BC1F1 fruits of some selected plants over the cv. ‘Momotaro’. Therefore, it can be concluded that the aromatic fragrance of a ‘L. peruvianum’ accession has successfully been introduced into the cultivated tomato gene pool.
Introgression of alleles of the isozymic locus glucosephosphate isomerase‐2 (GPI‐2) from the CC genome of Brassica carinata to the CC genome of Brassica alboglabra and their independent segregation from seed colour
Authors: Rahman M. H.
Published: March 2003

A yellowish brown‐seeded Brassica alboglabra was resynthesized from a (B. alboglabra×Brassica carinata) ×B. alboglabra cross, followed by self‐pollination. The resynthesized B. alboglabra lost the allele of the isozymic locus glucosephosphate isomerase‐2 (GPI‐2) from natural B. alboglabra, which was replaced by an allele from the corresponding genome in B. carinata. A simple Mendelian segregation of these two alleles was observed in the F2 population of a natural × resynthesized B. alboglabra cross. Furthermore, these two alleles segregated independently from the seed colour.
Resistance to cowpea mottle carmovirus in Vigna vexillata
Authors: Ogundiwin E. A. , Thottappilly G. , AkenOva M. E. , Ekpo E. J. A. , Fatokun C. A.
Published: March 2003

Cowpea mottle carmovirus (CPMoV) causes grain yield losses of up to 75% in cowpea (Vigna unguiculata [L.] Walp.). There is no resistance to this virus among cultivated cowpea lines, but a high level of resistance exists in Vigna vexillata, a wild Vigna species. Fifty‐four accessions of V. vexillata germplasm collection at IITA were tested for resistance to CPMoV. Seedlings were mechanically inoculated with the virus and susceptibility or resistance was assessed by visual scoring of disease symptoms and serological analysis using antigen‐coated plate enzyme‐linked immunosorbent assay (ACP‐ELISA). All but three V. vexillata lines belonging to the variety angustifolia were resistant to CPMoV. Crosses were made between two resistant V. vexillata lines and the three susceptible lines. Segregation patterns observed in the F2 and the backcross populations of all the crosses showed that resistance to CPMoV in V. vexillata is controlled by a single dominant gene, and the level of resistance conferred by this gene in V. vexillata is very high.
Development of self‐incompatible Brassica napus: (III) B. napus genotype effects on S‐allele expression
Authors: Ripley V. L. , Beversdorf W. D.
Published: March 2003

Use of self‐incompatibility (SI) as a pollination control method for Brassica napus hybrid production requires the development of a sufficient number of S‐alleles that are expressed consistently in a range of B. napus lines. Self‐incompatibility (SI) alleles have been transferred from Brassica oleracea and Brassica rapa into B. napus var. oleifera. An understanding of expression of these alleles in B. napus is essential for their commercial use. Four SI B. napus doubled haploids containing the B. oleracea S‐alleles S2, S5, S13 and S24 were crossed to three B. napus cultivars to measure the B. napus genetic background effect on S‐allele expression. A line x tester analysis indicated that the largest source of variation in the expression rate of SI was the S‐allele itself. The B. napus genotypes tested contained modifier gene(s), some that enhanced SI expression and others that inhibited SI expression. The B. napus Canadian cultivar ‘Westar’ generally had a negative effect on SI expression while the European cultivar ‘Topas’ had a positive effect on the B. oleracea S‐allele expression. The B. oleracea S‐allele S24 was very similar in expression to the B. rapa allele W1. The application of these results for the use of B. oleracea S‐alleles for hybrid production in B. napus is discussed.
Relationship between Sperm Response to Glycosaminoglycans in vitro and Non‐return Rates of Swedish Dairy AI Bulls
Authors: Januskauskas A , Gil J , Söderquist L , Rodriguez‐Martinez H
Published: March 2003

Contents

In this study, the relations between fertility (56‐day non‐return rates, 56‐day NRR) after artificial insemination (AI) and bull sperm characteristics post‐thaw, after swim‐up and after co‐incubation with heparin (Hep) and hyaluronan (HA), respectively, were determined, attempting to determine if such a procedure could be of value to evaluate the potential fertilizing ability of frozen‐thawed AI bull spermatozoa. Spermatozoa from 20 semen batches derived from 20 Swedish Red and White AI bulls ranging widely in their field fertility after AI (55–79% 56‐day NRRs) were evaluated with regards to post‐thaw motility, membrane integrity, and migration through a simple swim‐up procedure. Sperm viability and capacitation status were evaluated by two different vital staining procedures and chlortetracycline hydrochloride staining. Sperm motility and membrane integrity post‐thaw (e.g. indicators of sperm viability) were significantly correlated (r = 0.53, p < 0.05 and r = 0.59, p < 0.01, respectively) with fertility. Heparin (5 µg/ml) significantly (p lt; 0.001) increased the frequencies of capacitation and acrosome‐reaction (AR) among swim‐up separated spermatozoa, whereas HA at a concentration of 50 ng/ml did not have any significant capacitating effect. The incidences of capacitated or AR‐spermatozoa following Hep‐treatment were not correlated with fertility. On the other hand, the percentage of viable spermatozoa was significantly (p < 0.001) lower in Hep‐treated samples than in control and HA‐treated samples and was significantly (r = 0.49, p < 0.05) correlated with fertility after AI (56‐day NRR). The results indicate that the percentage of viable spermatozoa after swim‐up separation and heparin‐exposure from a selected population of AI bulls were significantly and positively related to the AI fertility of the donors and thus could be used as a parameter to determine the fertilizing ability of frozen—thawed AI bull spermatozoa.
Factors Modulating Apoptosis: an in‐vitro Study in Swine Granulosa Cells
Authors: Ponderato N , Grasselli F , Saleri R , Tamanini C
Published: March 2003

Contents

The aim of this study was to investigate the effects of some endocrine and intra‐ovarian factors on the activation/inhibition of apoptosis in swine granulosa cells. Upon incubation in a 10% FCS‐supplemented M199, granulosa cells from small (< 3 mm) follicles programmed their death after 24–48 h of culture; in the absence of FCS, apoptosis was reduced after 24 h of culture. Cells cultured in the presence of FCS were treated with db‐cAMP, LH, FSH, Insulin‐like Growth Factor‐I IGF‐I or PMSG to verify the role of these substances in apoptotic death: all these molecules inhibited apoptosis after 48 h of incubation. A further aim of the study was to investigate the possible involvement of nitric oxide (NO), an intra‐ovarian modulator, in the regulation of granulosa cell apoptosis and its possible role in the modulation of steroidogenesis. After a 48 h incubation with a substrate of NO synthesis ( l‐arginine, 0.1 and 1 m
m), a NO donor [S‐nitroso‐N‐acetyl‐penicillamine (SNAP) , 0.2 and 1 m
m] or a NO synthase inhibitor [Nω‐nitro‐
l‐arginine‐methyl‐ester (NAME, 1 and 5 m
m)], the onset of apoptotic death was evaluated:
l. arginine and NAME did not induce any significant variation of apoptosis, whereas 1 m
m SNAP exerted a protective action. A significant stimulatory effect of
l‐arginine on NO production, associated with a suppressive action on estradiol 17β concentrations was observed; NAME exerted an inhibitory effect on NO production, associated with an increase in estradiol secretion; estradiol 17β production was markedly inhibited by SNAP. In summary, the depletion of FCS could induce a cell cycle arrest in G0 whereas apoptosis could be the consequence of cell cycle progression mediated by FCS; gonadotropins and IGF‐I could also act as survival factors. NO appeared to represent a ‘trophic’ signal for the follicle, whose involvement in the regulation of ovarian function is substantiated by its modulatory action on steroidogenesis.