bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient in vitro Chromosome Doubling During Beta vulgaris Ovule Culture
Authors: Hansen A. L. , Plever C. , Pedersen H. C. , Keimer B. , Andersen S. B.
Published: April 2006

The effect of in vitro colchicine treatment of sugar beet ovules, after 7 days culture, on embryo formation, regeneration and ploidy of regenerated plants was studied with 5 concentrations of colchicine and 5 durations of treatment arranged as a 5 × 5 factorial in incomplete blocks. The best results were obtained with the shortest duration of treatment (5 hours) and the highest concentration of colchicine (0.4 %) giving 5.0 diploid plants per 100 ovules with 62.1 % of regenerated plants being diploid. Statistical analysis revealed that treatment effects could be separated into a toxic effect reducing embryo formation and a chromosome doubling effect affecting percentages of diploid regenerated plants. Toxic effects on embryo formation could be explained by simple exponential decay models, toxicity of the drug (decay constant) increasing linearly with duration of treatment. Duration of treatment had no effect on chromosome doubling percentages. The effects of colchicine concentration on chromosome doubling were explained by an exponential saturation model with spontaneous chromosome doubling of 8.1 % and saturation at 51.4 % diploid plants at 0.2 % and higher colchicine concentrations. In addition, treatments increased percentages of 4N and 6N plants from 0 % without colchicine to 10 % on average for treated ovules. A response surface model fitted to the total yield of diploid plants per ovule indicated that shorter durations of treatment and higher colchicine concentration may improve results.
Economic Aspects of Breeding for Yield and Quality Traits in Forage Maize
Authors: Mistele M. , Zeddies J. , Urz H. F. , Melchinger A. E.
Published: April 2006

The economic evaluation of forage maize is complex due to its usage in different types of farms as well as the interdependencies of forage maize traits with the farm organization and the intensity of production. By means of linear programming, the economic weights of important forage maize traits were calculated for farming conditions in Germany. They were determined from the difference in the gross margins of farm models for given changes in a single trait of forage maize and were calculated for dairy and bull‐fattening farms under five levels of animal performance, three stocking rates, and different levels of forage maize traits. Individual economic weights under these settings varied little in most cases and allowed aggregation of mean economic weights. They amounted to 4.6 ECU ha−1 for metabolizable energy yield (GJ ha−1), 207 ECU ha−1 for metabolizable energy content (MJ kg−1), and 3.1 ECU ha−1 for crude protein content (g kg−1). Economic weight for forage dry matter content was strongly dependent upon the maturity of the materials and varied between ‐5 and 25 ECU ha−1. The application of economic weights was discussed in comparison with other criteria for the assessment of experimental hybrids in official trials.
Economic Aspects of Breeding for Yield and Quality Traits in Forage Maize
Authors: Utz H. F. , Melchinger A. E. , Seitz G. , Mistele M. , Zeddies J.
Published: April 2006

Selection indices were calculated for simultaneous improvement of relevant forage maize traits. Beside indices based on primary traits [metabolizable energy yield (MEY) and content (MEC), crude protein content (CPC)] determined either in vitro or by near‐infrared reflectance spectroscopy (NIRS), we calculated indices based on secondary (five agronomic) traits. The required phenotypic and genotypic covanance matrices were estimated from a series with 120 maize hybrids tested at three sites. Base index, heritability index, optimum index, and restricted index showed only minor differences in the expected gain in total economic worth (ΔH) for the present agricultural conditions in Germany. CPC was the least important primary trait; selection for grain yield, the most suitable secondary trait, resulted in greater ΔH values than any other index. Harvesting the whole plant and subsequently determining MEC by NIRS was the most economic selection procedure with increased economic weighting for MEC at high animal performance levels. In the latter situation, we recommend grain yield trials as a pretest in breeding programmes and official performance trials for variety registration.
Inheritance of Maysin Content in Silks of Maize Inbreds Resistant to the Corn Earworm
Authors: Widstrom N. W. , Snook M. E.
Published: April 2006

Genetic information is needed on maysin, a compound in maize, Zea mays L., silks that is antibiotic to corn earworm larvae, Helicoverpa (formerly Heliothis) zea (Boddie), to assist in the process of breeding for resistance to this pest. This study was initiated to elucidate the inheritance of maysin content in the silks of a cross between two maize inbreds (GT114 and GT119) having resistance to the corn earworm. Reversed phase high performance liquid chromatography (HPLC) procedures were used to quantify the maysin concentration of silks from individual plants in the parent, F1, F2, and first backcross generations of the cross GT114 × GT119. A model assuming dominance at a single locus for low maysin content which is expressed only when a dominant modifier is present was proposed to explain the segregation ratios obtained in the F2 and first back‐crosses of GT114 × GT119. This model also provided a fit for maysin data previously generated from a cross between inbreds F6 and F44. Observations of selfed families in the backcross of GT114 × GT119 to the low maysin parent confirmed the two‐locus model (one factor with dominance for low maysin expressed only when a modifier gene is also present) as a plausible explanation for inheritance of silk maysin in the cross. The process of selection for high maysin will be complicated somewhat by the presence of a gene which modifies the expression of dominance unless a method of easily identifying the gene, independent of maysin content, can be developed.
Genetic Analysis of Some Chemotypes in Ocimum basilicum var. glabratum
Authors: Gupta S. C.
Published: April 2006

Screening of a population of Ocimum basilicum var. glabratum Benth., raised from seeds collected from France, West Africa and Kerala (India) was carried out for chemical composition of its essential oils. In all three collections, plants were found to be comprised of 3 chemotypes which were morphologically indistinguishable, but each chemotype was found to be capable of intercrossing freely with the other two.

Selfing was carried out during 4 consecutive generations, after which three pure lines were established. Study of the selfed progeny of each collection exhibited an interesting segregation in S2 and S3 generations. Along with segregation in F2 and F3 generations of various hybrids the results can be explained by assuming a gene ‘M’ existing in 3 (or more) allelic forms: The allele M0 for biosynthesis of estragole (methyl chavicol) is dominant to allelcs M1, for eugenol and M2 for camphor. Also, allele M1 is dominant to allele M2. The assumption was further confirmed by testcrosses of F1 hybrids of each cross with their recessive parent.
Screening for Greenbug Resistance in Hordeum chilense Roem et Schult.
Authors: Castro A. M. , Martin L. M. , Martín A. , Arriaga H. O. , Tobes N. , Almaraz L. B.
Published: April 2006

Schizaphis graminum (Rondani) is a serious pest of cultivated wheat (Triticum aestivum L.) and resistance is only available in other related species such as Hordeum chilense. Amphiploids between H. chilense and Triticum spp. have been obtained, and addition lines of H. chilense in wheat have been developed.

Thirty‐five accessions of H. chilense were screened to identify greenbug antixenosis, antibiosis and tolerance. Antixenosis was determined in a conventional host free choice test; antibiosis was measured by aphid life cycle and fecundity rate, and tolerance was tested in a conventional infestation test of 4 weeks. Two commercial barley cultivars were used as susceptible and resistant controls.

Eight H. chilense accessions showed higher degrees of antixenosis than the resistant check, 19 were similar and the rest were lower. All accessions were more resistant than the susceptible check. Measured by aphid life cycle, 22 H. chilense accessions showed higher antibiosis than the resistant cv., and all exhibited a higher antibiotic effect on fecundity rates than the control. A similar degree of tolerance to that of the resistant control was observed in six accessions, the remaining entries ranged between the controls. The presence of one mechanism did not exclude the existence of other mechanisms in the same entry and therefore, independence of the different mechanisms is proposed.

Most of the accessions showed higher variability than both controls for the three mechanisms, and it appears to be genetic variability within entries for the three mechanisms.
Transfer of the Glu‐D1 Gene from Chromosome 1D to Chromosome 1A in Hexaploid Triticale
Authors: Lukaszewski A. J. , Curtis Christine A.
Published: April 2006

To complement previously developed recombinant chromosomes 1R.1D, two series of translocations involving the Glu‐D1 gene from chromosome ID to chromosome 1A were produced in hexaploid triticale. These series involve seven independent transfers of allele d encoding for high molecular weight glutenin subunits 5+10 and ten independent transfers involving allele a encoding for HMW glutenin subunits 2 + 12. The frequency of homoeologous recombination between chromosomes 1A and 1D was within the range observed for pairs of homologues in wheat, supporting earlier observations that homoeologous recombination in triticale is frequent. Recombined chromosomes 1A.1D can be used to introduce the Glu‐D1 gene to durum wheats, and to manipulate the dosage of Glu‐D1 in hexaploid triticale and bread wheat.
Comparative Field Performance of Tissue Culture‐Derived Lines and Breeder Lines of HY320 Spring Wheat
Authors: Hanson K. , Huci P. , Baker R. J.
Published: April 2006

This study examines the performance of somaclonal spring wheat (Triticum aestivum L.) lines developed through culture of somatic embryos. Twenty‐nine breeder lines of the spring wheat cv. ‘HY320’ were compared to 51 somaclonal lines of the same cultivar. Somaclonal lines were derived from 27 individual embryos (with up to four lines in each “family”). Somaclonal and breeder lines were evaluated in five field experiments in western Canada. Somaclonal lines were more variable than breeder lines for most agronomic, yield component and quality characters, suggesting that variability among somaclonal lines resulted partly from the tissue culture process. Somaclonal lines yielded, on average, 11 % less than breeder lines. Somaclonal lines had 3.8 % fewer spikelets per spike, 6.5 % fewer kernels per spike and kernels which were 2.7 % lighter. Somaclonal lines had greater test weight, protein concentration, and sedimentation values, and harder kernels.
Addition of Colchicine to Wheat Anther Culture Media to Increase Doubled Haploid Plant Production
Authors: Navarro‐Alvarez W. , Baenziger P.S. , Eskridge K.M. , Hugo M. , Gustafson V.D.
Published: April 2006

Chromosome doubling is critical for obtaining doubled‐haploid plants from wheat (Triticum aestivum L.) anther culture. The most common doubling method applies colchicine to the plant. However, colchicine is phytotoxic and can induce a high frequency of plant death. In this experiment, anthers from two wheat genotypes (“Pavon 76” and ‘Centurk’) were placed on nine embryoid initiation media having three sugar sources (maltose, sucrose, and maltose + glucose) with three colchicine concentrations (0.0, 0.1, and 0.2 g · l‐1). Wheat starch was used as a gelling agent. After three days, the anthers were washed and moved to fresh media without colchicine. Increasing the colchicine concentration decreased the number of embryoids produced from 77.4 embryoids/100 anthers to 29.9 embryoids/100 anthers, but did not significantly affect the frequency of plant regeneration (0.49 green plants/embryoid to 0.40 green plants/embryoid), and increased the frequency of doubled‐haploid plants (19.0 doubled‐haploid plants/100 green plants to 72.3 doubled‐haploid plants/100 green plants). Considering the total number of doubled‐haploid plants produced, low levels of colchicine added to the initiation media were very effective.
Variation in Rate and Duration of Growth Among Spring Barley Cultivars1
Authors: Leon J. , Geisler G.
Published: April 2006

Ten two‐rowed spring barley cultivars (Hordeum vulgare L.) were evaluated for growth parameters, i.e. crop growth rate, crop growth duration, grain filling rate, grain filling duration, vegetative growth rate, vegetative growth duration, single caryopsis filling rate, single caryopsis filling duration. Field studies were conducted on a sandy loam at Hohenschulen, Northern Germany with three levels of nitrogen fertilization and three sowing rates in 1986 to 1988. Cultivar effects were observed for all growth parameters except for crop growth rate and vegetative growth rate. But only crop growth duration n and grain filling duration showed positive correlations with grain yield. No growth rate parameter was related to yield. Biomass was correlated to crop growth duration and not to crop growth rate, while average caryopsis weight was strongly related to caryopsis filling rate and only moderately to caryopsis filling duration. Comparing grain filling rate and duration to individual caryopsis filling rate and duration, only grain filling rate and duration appeared to be relevant to grain yield. Since genetic variability for crop growth rate was lacking in the spring barley material tested, further improvement of yield would only result from increase in harvest index and/or longer crop growth duration.
The Relationship Between Progeny Seed Yield in Drilled Plots and Maternal Spaced‐Plant Traits in Perennial Ryegrass (Lolium perenne L.)
Authors: Elgersma A. , Winkelhorst G. D. , Den Nijs A. P. M.
Published: April 2006

Seed production in perennial ryegrass, Lolium perenne L., is low. Early selection for high seed yield carried out in spaced plants would be valuable for breeders, but only if this potential is also expressed in derived progenies sown later in drilled plots. Therefore, spaced‐plant traits assessed on clonal ramets of 31 genotypes in each of two perennial ryegrass varieties in four environments were related to seed production characteristics in drilled plots of open‐pollinated progenies of these plants.

Significant differences were found among these half‐sib families for seed yield, thousand‐grain weight, spring performance and earliness. The number of spikelets per ear in the maternal plants was negatively correlated with the seed yield of the progenies, explaining 17 % of the variation for seed yield in the cv. ‘Barenza’ and 14 % in the cv. ‘Wendy’. Multiple regression analyses revealed that no combinations of plant traits consistently explained a major portion of the variation for seed yield of the progenies.

The results indicate that in these varieties, spaced‐plant data are of limited value in predicting seed production. Direct selection for seed yield in drills of progenies in later stages of the breeding programme remains the best method for obtaining varieties with sufficient seed production.
Identification and Inheritance of Fertility Restorer Genes for ‘tour’ CMS in Rapeseed (Brassica napus L.)
Authors: Sodhi Y. S. , Pradhan A. K. , Verma J. K. , Arumugam N. , Mukhopadhyay A. , Pental D.
Published: April 2006

Eighteen genotypes of Brassica napus were crossed to a cytoplasmic male sterile (CMS) line of B. napus BO 15 carrying B. tournefortii cytoplasm (‘tour’ cytoplasm). Fourteen genotypes were found to be stable maintainers of the ‘tour’ CMS. Of the remaining four genotypes, GSL‐1 and ‘Asahi‐natane’ were found to be heterozygous and ‘Mangun’ and ‘Yudal’ were homozygous for the restorer gene. Analysis of the F1 and F2 progenies of (CMS) BO 15 ×‘Mangun’ and (CMS) BO 15 ×‘Yudal’ showed that fertility restoration is controlled by a single dominant gene. The availability of a number of stable maintainer lines and the simple inheritance pattern of fertility restorer gene makes ‘tour’ CMS a useful system for hybrid seed production in rapeseed.
Plant Regeneration Through Anther Culture of Three Wild Species of Hordeum (H. murinum, H. marinum and H. bulbosum)
Authors: Kihara M. , Fukuda K. , Funatsuki H. , Kishinami I. , Aida Y.
Published: April 2006

Plant regeneration was achieved through anther culture of three wild species of Hordeum (H. murinum, H. marinum and H, bulbosum). Calli or embryoids were formed from microspores in anthers cultured on a medium containing 6‐benzylammopurine (BAP) and ficoll. These calli or embryoids regenerated green or albino shoots and roots after transfer to regeneration media. Green plantlets which developed on regeneration media were transferred to soil where they showed further growth.
Resistance to Coffee Berry Disease in Arabica Coffee Variety ‘Ruiru 11’
Authors: Omondi C. O.
Published: April 2006

General and specific combining ability effects for resistance to coffee berry disease (Colletotrichum coffeanum Noack sensu Hindorf) in Coffea arabica variety ‘Ruiru 11’ and its parents were estimated according to the North Carolina Design II. A set of nine male parents and eleven females were crossed in all possible combinations to generate ninety‐nine single cross hybrids constituting the ‘Ruiru 11’ variety. The parents and their hybrid progenies were screened and the mean score data analyzed for possible genetic variation. The contributions of the parents to the total genetic variance were low hence the low narrow sense heritability (h2= 0.04). The male and female parents accounted for 9.36 % and 0.96 %, respectively, while their interaction effect accounted for 89.68 %. In the analysis of combining ability for resistance, ExB3.96 and Cat.90 exhibited significant negative general combining ability (GCA). Specific combining abilities (SCA) were negative and significant for Cat.86 × ExB3.99, Cat.127 × ExB3.116 and Cat.119 × ExB3.879 crosses. The implications of these results in selection for highly resistant ‘Ruiru 11’ progenies are discussed.
Testing for Tolerance to Aphids in Indian Mustard, Brassica juncea (L.) Czern and Coss.
Authors: Abraham V. , Bhatia C. R.
Published: April 2006

Brassica juncea plants were screened for aphid tolerance using three methods. Seven and 14 days old seedlings grown in wooden trays in a glasshouse were kept between infector trays with heavy aphid infestation. There were no surviving plants in the susceptible genotypes 50 days after sowing but survival rates ranging between 80 and 90 % were observed for selection 44. The progenies of the surviving plants were tested under natural infestation in the field. Plants were scored for leaves without aphids 40 days after sowing, healthy plants at harvest and seed yield in g/m2 For most of these lines, the aphids’ survival, life span and fecundity (nymphs produced per adult) were recorded after introducing five newly‐born nymphs on excised fifth leaves cultured in petri dishes. Selections showing greater tolerance to aphids than the check cultivars were identified in the progenies of a cross RLM‐514 × T‐6342. It was concluded that the excised leaf method can provide a reliable measure of the lines’ reaction to aphids.
Mapping of Malt Endopeptidase, NADH Diaphorase and Esterase Loci on Barley Chromosome 3L
Authors: Guerin J. R. , Lance R. C. M. , Brown A. H. D. , Abbott D. C.
Published: April 2006

Isoelectric focusing (IEF) and immunoblotting were used to detect genetic variants of malt endopeptidase (MEP1), an enzyme related to malting quality in barley and coded by the CepB locus on barley chromosome 3 (= 3H). A variant was found in a Turkish accession of wild barley (Hordeum vulgare ssp. spontaneum). The self progeny of a hybrid between this accession and the barley cultivar ‘Clipper’ were analyzed for recombination between the CepB locus and other isozyme loci. The estimates of recombination linked the CepB locus to an NADH diaphorase locus (Ndh2), which in turn was linked to the seedling esterase complex (Est1, Est2, and Est4) situated near the distal end of the long arm of chromosome 3. The Ndh2 locus was independent of two other NADH dehydrogenase loci (Ndh3, Ndh5) which were mapped on barley chromosome 5 (= 1H) in relation to the three hordein loci (Hor1, Hor2, and Hor3).
Selection for Early Flowering Results in Simultaneous Selection for Reduced Nuclear DNA Content in Maize
Authors: Rayburn A. Lane. , Dudley J. W. , Biradar D. P.
Published: April 2006

Several studies have indicated a possible link between genome size and earliness in maize. In this study, an original maize population, South African photo‐period insensitive maize composite II (C0) and several selected generations were analyzed for days to flowering, plant height, ear height, and yield. The selection criterion was earliness. Over six cycles of selection a 14‐day decrease in days to flowering was obtained with no significant reduction in grain yield. In the initial population (C0) and the most advanced selection (C6) 101 plants were analyzed for nuclear DNA content. A significant decrease in the mean nuclear DNA content of the C0 population (102 AU) was observed with respect to the C0 population (105 AU). This reduction was the result of a decrease in frequency of plants in the C6 population with large genome sizes. Therefore it was concluded that selection for earliness resulted in selection against plants with large genome sizes. Hence, the nucleotype of a maize plant can be modified by selection such as early flowering time.
Identification of an RAPD Marker Linked to theVfGene for Scab Resistance in Apples
Authors: Yang Hongyu , Krüger Jutta
Published: April 2006

Resistance toV. inaequalis, derived from the small‐fruited speciesMalus floribunda821, is determined by a major dominant gene, assigned asVf.The material used in this paper is based on the introgression of theVfgene fromM. floribundainto commercial apple varieties. Comparing RAPD patterns of a genomic DNA sample ofM. floribundawith a pooled DNA sample of resistant individuals and that of 10 susceptible commercial apple varieties, fragments were identified which are derived fromM. floribunda.One of them, the fragment OPD20/600, proved to be linked to theVfgene with a recombination value of about 0.20—0.25. It is the first DNA marker so far for scab resistance.
Isoenzyme Electrophoresis, a Simple Way to Identify 1B/1R Substitutions and Translocations in Wheat
Authors: Hartmann H. , Schiele S. , Lelley T.
Published: April 2006

In order to identify 1B/1R translocations and substitutions by simple means in breeding materials, the efficiency of using starch gel electrophoresis of isoenzymes was evaluated. GPI (glucose phosphate isomerase) and MDH (malate dehydrogenase) were tested in 17 lines of wheat which had previously been identified for their 1B/1R status by C‐banding. By electrophoresis of these two enzymes the rye substitution of only one wheat chromosome arm could be identified with high accuracy.
Interspecific Crossability and Inheritance in Pelargonium
Authors: Horn W.
Published: April 2006

Different Pelargonium hybrids are of great importance to horticulture. Breeding; for F1 hybrid and clonal eultivars is particularly prevalent in Europe, Japan and North America. The results of a great deal of breeding research are scattered throughout different journals and published in several different languages. The aim of this review is to summarize the results of research on interspecific crosses and the inheritance of flower and leaf colour, plant habit, resistance and floret type.
Preliminary Diallel Analysis of Anther Culture Response in Wheat (Triticum aestivum L.)
Authors: Ekiz H. , Konzak C. F.
Published: April 2006

A four‐parent complete dialleld mating‐set of three Triticum aestivum L. cultivars ‘Edwall’, ‘Chris’ and ‘Spillman’, and an alloplasmic line of ‘Selkirk’ in Aegilops variabilis Eig. cytoplasm was used. Genetic components among total variation for callus induction, green plant percentage and green plant yield werr 92%, 80% and 77%, respectively, but lower (36%) for plant regeneration. General combining ability (GCA) variance components and narrow‐sense heritabilities estimated for callus induction, green plant pereentnge and green plant yield were 74%, 66%, and 53%, and 0.68, 0.54 and 0.43. respectively. Specific combining ability (SCA) variancw was calculated as 85%) of total genctie variation for plant regeneration. Significant reciprocal effects for callus induction. green plant percentage and green plant yield were observed.
Response of Wheat Grain to ABA and Imbibition at Low Temperature
Authors: Noda K. , Kawabata C. , Kawakami N.
Published: April 2006

During after‐ripening of wheat grains, embryo responsiveness to abscisic acid (ABA) decreases in parallel with the loss of grain dormancy. Dormant grains of Triticum aestivum L. line ‘Kitakei‐1354’ that had lost almost half their dormancy due to chilling still respond to ABA like fully dormant grains. Imbibition a: low temperature appears to break the dormancy without change of embryo responsiveness to ABA. Gibberellin (GA) and ABA‐regulated α‐amylase synthesis of the embryos. This is amplified when the grains are imbibed at low temperature. Imbibition at low temperature appears to condition cells and tissues of the embryo for germination and α‐amylase synthesis.
The Use of Ovule Culture in Reciprocal Hybridization between B. campestris L. and B. oleracea L.
Authors: Diederichsen E. , Sacristan M. D.
Published: April 2006

Ovule culture was used to overcome postzygotic interspecific incompatibility in reciprocal crosses between Brassica campestris and B. oleracea. Hybrid plants were obtained from 82 % of all reciprocal pollinations, representing 91 % of the attempted combinations. Comparisons of the embryo culture and the ovule culture indicated a significantly higher germination rate after ovule culture.
Gibberellic Acid + 2,4‐D Improves Seed Quality in Hordeum vulgare L. ×H. bulbosum L. Crosses
Authors: Pickering R. A. , Wallace A. R.
Published: April 2006

Doubled haploid production from crosses between barley (Hordeum vulgare L.) and H. bulbosum L. is a well established technique for inducing homozygosity. One problem which occurs using certain barley cultivars is premature seed degeneration. In this paper, a post‐pollination spray of gibberellic acid and 2,4‐dichlorophenoxyacetic acid that delays the onset of senescence is described. The technique improved the number of high quality seeds to more than 75% of the seed set. This improvement should result in increased survival of embryos for culture and subsequent plant regeneration.
Adaptation Patterns and Definition of Macro‐environments for Selection and Recommendation of Common‐wheat Genotypes in Italy
Authors: Annicchiarico P. , Perenzin M.
Published: April 2006

Eighteen common‐wheat varieties grown for three seasons at 31 locations in Italy were used to study the relationships between cultivar adaptation patterns, climatic factors and morphophysiological traits of genotypes, as well as defining macro‐environments for the selection and recommendation of genotypes in the region. The variances of both the genotype‐location and genotype–season interactions were significant, the former being almost 80% greater than the latter. Some 10.4% of genotype‐location interaction was accounted for by heterogeneity of genotype regressions on site mean, 38.0% by the first two axes of a principal components analysis and 32.0% by definition of four macro‐environments. Occurrence of genotype‐location interaction was related to the level of late frosts, winter cold, and late drought and heat stress at each location, and to heading date and tolerance of frost, Septoria blotch and lodging in each genotype. Following estimates of broad‐sense heritability, breeding for specific adaptation may be envisaged for northern and central Italy on the one hand, and southern Italy on the other. Morphophysiological traits contributing to better performance in each of these macro‐environments were indicated.
Identification and Genetic Studies of the Inhibition of Dominant Male Sterility in Brassica napus
Authors: Zhou Y. M. , Bai H. H.
Published: April 2006

By transferring dominant male sterility (DMS), caused by the gene Ms, to genotypes with various types of cytoplasm 12 DMS lines were developed and a number of crosses made between the DMS lines and other genotypes of Brassica napus. During the course of this population improvement programme, 16 genotypes were identified as having the capacity to restore the fertility of F1 plants with the Ms gene. According to pedigree analysis, the inhibitory gene in those lines probably originated from a few genotypes from Australia and Germany. In further studies the inheritance of the sterility inhibition was determined, providing definite evidence that dominant male sterility and its inhibition in B. napus are controlled by two dominant interacting genes rather than by multiple alleles.
Effect of Cytoplasmic Source on the Combining Ability of Agronomic Traits in Pearl Millet
Authors: Yadav O. P.
Published: April 2006

Among the available sources of cytoplasmic male sterility only the A1 source has so far been exploited for breeding commercial hybrids of pearl millet (Pennisetum glaucum (L.) R. Br.). The influence of this source was studied by comparing the combining ability of five pairs of lines that differ in their cytoplasmic source. The effect on the expression of the traits, though modified by environment, was significant. The manifestation of cytoplasmic effects on general combining ability (GCA) was different for various traits. In general, the A1 cytoplasm showed a positive influence on GCA estimates for plant height, grain yield, and a negative influence on days to flowering. The variable magnitude of cytoplasmic effects on the GCA of lines indicated that such effects were the result of interaction between cytoplasm and nuclear genes.
Recombination within the Gli‐B1 Locus in Durum Wheat
Authors: Margiotta B. , Colaprico G. , Urbano M. , Lafiandra D.
Published: April 2006

Recombination within the closely linked genes encoding for omega and gamma gliadins at the complex Gli‐B1 locus present on the short arm of chromosome 1B was detected in a durum‐wheat line (Triticum durum) from Iran. This recombinant differs from a previous one the authors detected in the durum‐wheat cultivar ‘Berillo’ since it shows the gamma gliadin component 45 associated with a triplet of omega components usually found linked with the allelic gamma gliadin 42. Analysis of low‐molecular‐weight glutenin subunits, encoded by genes at the complex Glu‐B3 locus associated with the Gli‐B1 locus, showed the presence of the protein type designated LMW‐1 which is peculiar to durum‐wheat cultivars possessing the gamma gliadin 42.
Monogenic Semidominant Sulfonylurea Resistance in a Line of White Chicory
Authors: Lavigne C. , Millecamps J.L. , Manac'h H. , Cordonnier P. , Matejicek A. , Vasseur J. , Gasquez J.
Published: April 2006

This paper reports on a chlorsulfuron‐resistant line of white chicory (Cichorium intybus cv. ‘Witloof’) regenerated from non‐mutagenized cell cultures. The resistance was inherited as a monogenic semi‐dominant trait. Homozygous resistant individuals withstood doses of herbicide 1500 to 2000‐fold higher than the susceptible ones, whereas this ratio was around 300 for the heterozygotes. Cross‐resistances to seven other sulfonylureas and to one imidazolinone were revealed, leading to the conclusion that this resistance could be due to mutation of the target enzyme.
Effect of Selection for Chip Colour on Some Economic Traits of Potatoes
Authors: Pereira A. da S. , Tai G. C. C. , Yada R. Y. , Tarn T. R. , Souza‐Machado V. , Coffin R. H.
Published: April 2006

The objective of this study was to investigate the effects of selection for chip colour after harvest (CH), after storage at 12. 8°C (OR), and after storage at 3°C (GO) on maturity, yield, tuber size and specific gravity. Three hybrid populations of random clones were used in this study. The parents plus seven other cultivars were also evaluated, as checks. Experiments were carried out at Benton Ridge and at Fredericton, NB, in 1991. The experimental design was an augmented block. Clones of populations were non‐replicated and distributed randomly in the experiment. Check cultivars were replicated four times in a randomized complete block design. Negative responses were predicted for maturity, marketable and total yield, and tuber size (agronomic traits) and positive response for specific gravity in varying amounts for the three populations by selection for the three chip quality traits (CH, CR and CC). Therefore, selection for CH, CR and CC and the agronomic traits could not be made without some adverse effects on each other, whereas chip quality traits and specific gravity could be improved simultaneously.
Soyabean‐seed Yield Response in Row‐ and Hill‐plots under a Recurrent Selection Programme
Authors: Bello L.L. , Kenworthy W. J.
Published: April 2006

The objective of this study was to evaluate F4 lines in both row‐ and hill‐plots for agronomic traits in order to test the effectiveness of selecting high‐yielding S1 soyabean (Glycine max (L.) Merr.) lines selected in hill‐plots after two cycles of recurrent selection.

There was a cumulative seed yield loss of 197 kg/ha from cycle C0 to C2 when the selections were evaluated in row‐plots but a cumulative gain in seed yield of 533 kg/ha from C0 to C1 was observed when the selections were evaluated in hill‐plots. Ranking of seed yield between row‐ and hill‐plots showed a non significant association, but correlation coefficients between the two methods of testing were positive and highly significant for height, lodging and maturity. Thus, evaluation of height, lodging and maturity can be carried out effectively with either method of planting. There were increases in plant height, in lodging scores and in days to maturity with each cycle of selection. These changes were evident in both row and hill‐plots. The lack of seed yield response to selection as measured in row‐plots and a non‐significant association between the two plot arrangements indicated that seed yield evaluation by S1 testing in hill‐plots was not a reliable procedure in the identification of productive genotypes.
Relationship between Tolerance to Phytophthora Rot and Soybean Yield
Authors: Martin S. K. St. , Scott D. R. , Schmitthenner A. F. , McBlain B. A.
Published: April 2006

Phytophthora rot is a major soybean disease in the Eastern US corn belt. The objective of this experiment was to determine the genetic relationship between tolerance to phytophthora rot and agronomic traits measured in environments where the disease was not a factor. A set of 66 random lines from a broad‐based population was evaluated for agronomic traits in seven field environments and for tolerance in greenhouse tests. Pairs of resistant and susceptible isolines were used to determine whether phytophthora rot was present in the field environments.

The phenotypic correlation between tolerance and yield in five environments where phytophthora was negligible was non‐significant (r =−0.09). There was a positive correlation between tolerance and seed weight (r = 0.31) and a negative correlation between tolerance and plant height (r=–0.25). None of these correlations is large enough to hinder development of agronomically acceptable, tolerant cultivars.
Inheritance of Seed Dormancy in Lisianthus (Eustoma grandiflorum)
Authors: Ecker R. , Barzilay A. , Osherenko E.
Published: April 2006

The genetics of chill‐related seed dormancy, exhibited by a lisianthus (Eustoma grandiflorum) genotype native to North America, was investigated. Less than 1 % of the seeds germinated by direct hydration at 20°C, while full germination (98%) was attained by chilling imbibed seeds, for at least 11 days, at 3°C, before transferring them to 20°C. The inheritance of seed dormancy was analyzed in F1, BC1, and F2, populations, derived from mating between a normal non‐chill‐requiring genotype (P1) and the above chill‐requiring genotype (P2). F1 seeds, of both reciprocals, and BC1 (P1) seeds were all non‐dormant. The proportion of seed dormancy in F2 and BC, (P2) was 0.06 and 0.68, respectively. The inheritance model proposed includes six diallelic loci with cumulative effects, in which the presence of at least nine ‘dormancy‐conferring’ alleles is necessary for inducing phenotypic seed dormancy. Possible implications of inherent seed dormancy on the utilization of native lisianthus germplasm for breeding are discussed.
Oryzalin as an Efficient Agent for Chromosome Doubling of Haploid Apple Shoots in vitro
Authors: Bouvier L. , Fillon F. R. , Lespinasse Y.
Published: April 2006

In an outbreeding species such as apple, haploid plants may be especially useful in breeding programmes for the production of homozygous material. However, methods must be available to induce chromosome doubling in the haploid plants. Two antimitotic agents, colchicine and oryzalin, were compared as regards their efficiency in inducing chromosome doubling of in vitro haploid apple shoots. Three colchicine levels (0.025, 0.25 and 1.25 mM) and three oryzalin levels (5, 15 and 30 μM) were evaluated. Three techniques were also used and compared. Survival rate and chromosome counts were determined. Differences were observed between the two antimitotic agents and between the three techniques. This study demonstrates that oryzalin could be a better choice than colchicine for chromosome doubling on haploid apple shoots in vitro.
Responses to salt stress controlled by the homoeologous group 5 chromosomes of hexaploid wheat
Authors: Koebner R. M. D. , Martin P. K. , Orford S. M. , Miller T. E.
Published: April 2006

The responses to salt stress in NFT (nutrient film) hydroponics of ‘Chinese Spring’ wheat and a number of its aneuploids involving the chromosomes of homoeologous group 5 were studied. This showed that the absence of chromosome 5D allowed plants to survive better than in the euploid condition. Much of this response could be related to the effects of Vrn3, which conditions the spring habit of ‘Chinese Spring’. The ability to survive relatively high levels of stress was promoted by the group 5 homoeologue from Thinopyrum bessarabicum.
Somaclonal variation in three Argentinean varieties of Triticum aestivum with different karyotypic instability*
Authors: Franzone P. M. , Suárez E. Y. , Solari R. M. , Favret E. A. , Rios R. D. , Díaz Paleo A. H.
Published: April 2006

Three cultivars of wheat showing different levels of spontaneous karyotypic instability were studied regarding their stability in vitro for a number of characters, i.e. chromosome structure, gliadin pattern, glume and grain colour, awn type, chlorophyll pigmentation and plant morphology. The progenies of somaclones derived from immature embryos of both aneuploid and euploid plants were used in this study along with foundation seeds and a large number of their sexual progeny in order to discriminate between pre‐existent variability and any novel variation induced by the in vitro culture. Only one translocation not described before and a new gliadin pattern were detected which could be ascribed to the effects of tissue culture, suggesting that this technique is not effective for inducing novel variation for breeding purposes in wheat.
Regional distribution of resistances to powdery mildew in winter and spring barley cultivars grown in the northern part of France
Authors: Caffier V. , Vallavieille‐Pope C. de
Published: April 2006

The spatio‐temporal distribution of race‐specific resistances to powdery mildew was analysed in northern France (the east, the north and the west of Paris). Resistances were identified in 26 winter and six spring barley cultivars. Seedling leaf segments were inoculated with 20 powdery mildew isolates, chosen to identify 14 resistance alleles. As opposed to other European countries, the resistance alleles differed between winter and spring cultivars grown in the three regions. Most of the winter cultivars had no resistance allele, or only the widespread resistance alleles Mlra and/or Mlh, plus Mlg in the west. Mla9 and Mla13 were also present in the north, but at a low frequency. Spring cultivars carried the alleles Mla7, Mla9, Mla12, Mlk, Mlg or MlLa in the east, where a diversification of resistances has occurred since 1987, particularly because of the use of ‘Volga’ (Mla7, Mlk, Mlg and MlLa). In the north and the west, Mla12 dominated after a decrease in the frequency of Mla7, Mla13 has recently been introduced in the north and the west with the cultivar ‘Vodka’.
Successful hybridization between Lolium and Dactylis
Authors: Oertel C. , Fuchs J. , Matzk F.
Published: April 2006

In order to test crossability of Lolium and Dactylis, a total of 4126 florets of six different varieties and ploidy levels of Lolium multiflorum Lam. and L. perenne L. were pollinated using a blend of pollen from two cultivars and three ecotypes of Dactylis glomerata L. Additionally, reciprocal pollinations were carried out on 363 florets of two D. glomerata cultivars with pollen of L. multiflorum. Both pre‐ and post‐zygotic cross barriers were strong. Auxin application was effective in overcoming post‐zygotic barriers. One viable hybrid plant arose from 16 embryos. The hybrid between L. multiflorum and D. glomerata showed characteristics of both parents. The symmetric character of the hybrid was confirmed by genomic in situ hybridization. Backcross pollinations with pollen of both parents yielded two plants from five embryos with L. multiflorum only. Both the production of allopolyploid hybrids having characters of both species and the transfer of useful characters of D. glomerata into L. multiflorum should be possible.
Extent of RFLP variability in tetraploid populations of alfalfa, Medicago sativa
Authors: Pupilli F. , Businelli S. , Paolocci F. , Scotti C. , Damiani F. , Arcioni S.
Published: April 2006

Seven widely‐cultivated alfalfa varieties and three ecotypes adapted to Central Italy were used to evaluate the extent of polymorphism in that species. Twenty plants per accession were analysed with 16 RFLP probes combined with three restriction enzymes (48 probe/enzyme combination in total) and the data were used to compute the Nei's similarity index taken as a measure of inter‐ and intra‐population RFLP variability. The varieties were, in general, more homogeneous than the ecotypes and the cultivars ‘Adriana’ and ‘Florida’ could be differentiated more easily than the others. Few accession‐specific hybridizing fragments were scored and seven populations could be distinguished from the others on the basis of significant differences in the frequencies of specific fragments. The DNA of plant populations of several sizes was bulked and the ability to detect a given fragment in pooled samples was related to the fraction of plants having that fragment among the plants forming the bulk. The results are discussed with special emphasis on the practical utilization of RFLPs for varietal identification.
Varietal identification in Cichorium intybus L. and determination of genetic purity of F1 hybrid seed samples, based on RAPD markers
Authors: Bellamy A. , Vedel F. , Bannerot H.
Published: April 2006

Random amplified polymorphic DNA (RAPD) markers were used to distinguish between several Cichorium intybus genotypes, comprising four white witloof inbred lines, three red witloof experimental inbred lines and a number of F1 hybrids derived from two white parents. Amplification conditions and reproducibility of RAPD patterns were examined. Comparison of polymerase chain reaction (PCR) products obtained by using 100 10‐mer arbitrary primers allowed identification of all the lines analysed. With several primers, we defined line‐specific RAPD markers, while with others polymorphism was more extensive, revealing several RAPD markers for several lines. All the differences were confirmed both on individual heads and young seedlings for each genotype. Because of the Mendelian segregation of these molecular markers, this method was applied to evaluate the genetic purity of F1 hybrid seed samples.
Prediction of corrosion fatigue lives of aluminium alloy on the basis of corrosion pit growth law
Authors: ISHIHARA S. , SAKA S. , NAN Z.Y. , GOSHIMA T. , SUNADA S.
Published: April 2006

Tension‐compression and rotating‐bending fatigue tests were carried out using aluminium alloy 2024‐T3, in 3% NaCl solution. The corrosion pit growth characteristics, and also the fatigue crack initiation and propagation behaviour were investigated in detail. The results obtained are summarized as follows: (i) Most of corrosion fatigue life (60–80%) is occupied with a period of corrosion pit growth at low‐stress amplitude. The corrosion pit growth law can be expressed as functions of stress amplitude σa and an elapsed time t. (ii) The critical stress intensity factor for crack initiation from the corrosion pit was determined as 0.25 . This value is the same as the threshold stress intensity factor range for crack propagation. (iii) Corrosion fatigue life can be estimated on the basis of corrosion pit growth law and crack propagation law. The estimated fatigue lives agree well with the experimental data.
Detection of eating difficulties after stroke: a systematic review
Authors: Westergren A.
Published: April 2006

Background: It is highly important in nursing care for persons with stroke to screen for, assess and manage eating difficulties. The impact on eating after stroke can be of different types, comprising dysphagia as well as eating difficulties in a larger perspective. Eating difficulties can cause complications such as malnutrition, dehydration, aspiration, suffocation, pneumonia and death. There is a lack of systematic reviews about methods to be used by nurses in their screening for eating difficulties.

Aim: This review aims at systematically capturing and evaluating current peer‐reviewed published literature about non‐instrumental (besides pulse oximetry) and non‐invasive screening methods for bedside detection of eating difficulties among persons with stroke.

Methods: A search was performed in Medline and 234 articles were obtained. After a selection process 17 articles remained, covering seven screening methods and including about 2000 patients.

Conclusion: Best nursing practice for detecting eating difficulties includes as the first step the Standardized Bedside Swallowing Assessment (SSA) to detect dysphagia (strong evidence). As the second step an observation should be made of eating including ingestion, deglutition and energy (moderate evidence). Applying pulse oximetry simultaneously to SSA can possibly add to the accuracy of aspiration detection, especially silent aspiration (limited evidence). The methods should be used as a complement to interviews.
Caring for the terminally ill: experiences of Latvian family caregivers
Authors: Kalnins I.
Published: April 2006

Aim:  To increase understanding of the experiences and needs of family caregivers of terminally ill persons in Latvia.

Background:  Latvia has high death rates from cardiovascular disease and cancer, and families care for the terminally ill with little preparation and support. Health professionals also have little preparation in supporting these patients and families at the end of life.

Methods:  A qualitative study was carried out in the summer of 2004 in Latvia. Data collection was by semi‐structured interviews with caregivers (n = 18) whose care recipients died at least 1 year previously.

Findings:  The caregiver narratives addressed experiences that paralleled the trajectory of the patient’s illness: the disruption of normal life patterns; taking on the caregiver role; establishing new patterns and learning role competencies; engaging in preparation for dying; and the gains and losses of the caregiving experience as seen in retrospect.

Conclusions:  The caregiver narratives suggested a need for more education in practical caregiving; access to patient care equipment and supplies; and a need for ongoing support and guidance by knowledgeable medical personnel during caregiving.