bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field evaluation of transgenic Brassica napus lines carrying a seed‐specific chimeric 2S albumin gene
Authors: Denis M. , van Vliet A. , Leyns F. , Krebbers E. , Renard M. 
Published: April 2006

AbstractThe agronomic performance of transgenic Brassica napus lines carrying chimeric 2S albumin seed protein genes was studied under field conditions. A total of 37 transgenic lines were compared to non‐transformed lines. Plant development, morphological characteristics, yield parameters and seed composition were considered. Only a few transgenic lines differed from the control, and then only for particular parameters: four lines had altered leaf morphology, two differed in germination efficiency, one differed in yield, and three differed in some parameters of seed composition. These differences were not correlated with the presence or expression of the transgene and, thus, were more probably linked to cell‐ or tissue‐culture effects, or to residual variation present in cv. ‘Drakkar’. A statistical interaction between variations in a limited number of seed composition parameters and cell haploid culture was observed.While the expression of the chimeric 2S albumin gene was not as high as hoped, this study demonstrates that transgenic lines can be isolated in which the intrinsic morphological and agronomic properties of the original lines are maintained.
Effect of powdery mildew (Erysiphe graminis f.sp. hordei) on photosynthesis and grain yield of partially resistant genotypes of spring barley (Hordeum vulgare L.)
Authors: Balkema‐Boomstra A. G. , Mastebroek H. D. 
Published: April 2006

AbstractThe effect of powdery mildew on the photosynthesis and grain yield of partially resistant spring barley was investigated. The effect of powdery mildew on the CO2 exchange rate (CER) of inoculated and non‐inoculated leaves was measured in several glasshouse experiments. Grain yield reduction by powdery mildew was determined in three field experiments. The CER of the inoculated leaves was reduced by infection but that of the non‐inoculated leaves was not significantly different from that of the corresponding leaves of the control plants. The reduction in CER of the different genotypes was closely related to the percentage leaf area infected with powdery mildew.The correlation between degree of mildew infection and grain yield reduction varied between r = 0.84 (significant at P = 0.01) and r = 0.41 (not significant). Differences in greenness of the crop were correlated better with grain yield reduction (r = 0.66, P = 0.01) than powdery‐mildew infection itself. Low percentages of powdery‐mildew infection did not lead to significant reduction in grain yield. Partial resistance to powdery mildew could thus be a valuable attribute of future barley varieties.
Effects of selection and opportunities for recombination in doubled‐haploid populations of barley (Hordeum vulgareL.)
Authors: Iyamabo O. E. , Hayes P. M. 
Published: April 2006

AbstractDoubled‐haploid breeding systems are typically based on sampling gametes from F1plants. However, in the case of repulsion linkages, additional recombination could be advantageous. Pre‐selection of gamete donors might also shift progeny performance in a desired direction. The objectives of this study were to quantify the effects of an additional round of recombination and assess the effectiveness of pre‐anthesis selection in the production of barley doubled haploids. Assessments were conducted on: 1. 100 F1‐derived lines representing a subset of lines used in previous genome‐mapping studies; 2. 100 random F2‐derived lines; and 3. 50 F2‐derived lines from gamete donors selected for early heading. An additional round of recombination had only a modest effect on generating more favourable genotypes. Pre‐anthesis selection was ineffective in generating an earlier heading population. According to published quantitative‐trait locus (QTL) analyses based on the F1‐derived population, there are few repulsion linkages between QTL determining the traits measured in this experiment. Any advantages to be gained from postponing the generation of derivation of doubled haploids must be weighed against the delay and additional cost.
Production and cytogenetics of tetraploid–octoploid Avena hybrids
Authors: Katsiotis A. , Forsberg R. A. 
Published: April 2006

AbstractThe objectives of this research were to gather hybridization information about crosses between tetraploid and synthetically derived octoploid lines of Avena and their reciprocals, and to study the cytology of the hybrids obtained. When the octoploid plants were used as females, only 2.6% of the pollinated florets set seed, while seed set increased to 39.0% in reciprocal crosses. However, germination was 95.7% for the first group of hybrids and only 18.2% for the reciprocals. These diverse results can be explained by the paternal: maternal endosperm genomic ratios and the hypothesis of polar nuclei activation. The tetraploid‐octoploid hybrids did not always contain 42 chromosomes. Octoploid lines derived indirectly from tetraploid (AABB) × hexaploid (AACCDD) crosses were found to retain their A and B genome chromosomes. Univalents in the above hybrids averaged 15.44 in 1990 and 15.15 in 1991, indicating the presence of C and D genome chromosomes inherited from the octoploid lines. Directly synthesized octoploids from diploid (AcAc) × hexaploid (AACCDD) crosses were found to form 20.44 univalents, 5.30 bivalents, and 2.69 trivalents when crossed with AABB tetraploid species. The high number of univalents indicates that chromosomes from at least three genomes, i.e. B, C, and D, remain unpaired, while trivalents are the result of homology between the A and Ac genomes. Hybrids between tetraploid and octoploid lines can be obtained at low frequencies but, regardless of the direction of the cross, these hybrids are highly sterile.
Genetic variation in the feeding efficiency of maize genotypes evaluated from experiments with dairy cows
Authors: Barrière Y. , ÉMile J.‐C. , Traineau R. , Hébert Y. 
Published: April 2006

AbstractGenetic variation in the feeding efficiency of maize genotypes was evaluated from experiments with dairy cows. Maize genotypes were chosen to represent a range of digestibilities from previous experiments with standard sheep.The variation in milk yield observed with dairy cows fed genotypes with low or high digestibilities or energy values was about 1.0–2.0 kg per animal per day. Moreover, the range of variation in body weight was about 10–30 kg during the 3 months of the experiments. Hybrids with similar energy values had a similar effect on milk yield, but the intake of each hybrid could be very different when they were fed to dairy cows, even if no difference in intake had been observed in sheep. The higher silage maize intake of ‘DK265’ was mostly converted into a body weight gain rather than an increased milk yield, probably because the milk yield potential of the animals was soon reached. It appeared that those hybrids whose predicted energy value from sheep measurements was low led to relatively low performances in cows. Dairy cow performances also appeared to be related to the enzymatic solubility values of the whole plants.For maize breeders, the prediction of hybrid efficiency in dairy cow rearing must include digestibility and ingestibility factors. The most important challenge for maize breeders now will probably be the adjustment of a criterion for predicting intake because the stover digestibility and the starch content can be predicted reliably with the use of NIRS calibrations.
Breeding for resistance to rhizomania in sugar‐beet (Beta vulgaris L.)
Authors: Büttner G. , Märländer B. , Manthey R. 
Published: April 2006

AbstractIn breeding for resistance to rhizomania, breeding material was routinely examined for resistance to the rhizomania virus over several years. This study was performed in order to investigate the value of virological examination of sugarbeet breeding material in breeding for resistance to the rhizomania virus. Tests were conducted with varieties susceptible or partially resistant to rhizomania, as well as with several new and more‐resistant hybrids.A test on young plants showed that all genotypes contained beet necrotic yellow‐vein virus (BNYVV), but that the virus content differed widely. Plants of two commercially used partially resistant varieties had, on average, only half the virus content of susceptible varieties in their roots, and plants of eight new hybrids still in the process of registration contained less than one third of that amount.There was a significant negative correlation between the quantity of BNYVV in young plant roots and final yield under disease conditions in the field. Opportunities for further improvement in the level of the resistance to BNYVV in sugarbeet by means of conventional breeding programmes are discussed.
A rapid and simple method of producing high‐resolution zymograms from Brassica and related species on isoelectric‐focussing gels
Authors: O'Neill C. M. , Mathiasu R. J. 
Published: April 2006

AbstractIsozymes are potentially valuable genetic markers in the identification of hybrid plants, the assessment of seed purity, and in molecular and conventional genetic maps. The starch gels commonly used to prepare Brassica zymograms have very low resolutions. Consequently, isoelectric‐focussing polyacrylamide‐gel electrophoresis was explored as a means of producing high‐resolution zymograms of four Brassica isozymes. Crude sap extracts were found to be unsuitable for electrophoresis. Centrifugation, passage over sepharose beads and overnight dialysis were tested as alternative means of clarifying samples. The zymograms presented here demonstrate that isoelectric focussing, following overnight sample dialysis, results in zymograms which, in comparison to their starch counterparts, have vastly improved separation and resolution.
Breeding for impact resistance in potato: use of a pendulum in progeny testing
Authors: Rousselle P. , Gravoueille J. M. 
Published: April 2006

AbstractBreeding for impact resistance in potato is common at the end of a breeding scheme, where there is no more variability for it. The purpose of this study was to propose an objective progeny test using a pendulum and single‐year data. Data were recorded over a 5‐year period using 275 progenies, organized in small factorial and hierarchical designs. The variability of response of the additive variance made it impossible to generalize parental choice. However, once the crosses were made, the high degree of variability among the progenies and the high level of broad‐sense heritability in every case suggest that selection can be carried out efficiently using single‐year data.
Changes in the genetic structure of wheat germplasm accessions during seed rejuvenation
Authors: Zeuli P. L. Spagnoletti , Sergio L. , Perrino P. 
Published: April 2006

AbstractChanges in the genetic structure of wheat accessions caused by interspecific competition during periodic seed rejuvenation at a gene‐bank were studied. Electrophoretic patterns (Acid‐PAGE) of gliadin storage proteins were used to discriminate bread from durum wheat and to identify bread‐wheat genotypes. Bread wheat shows high selective advantage over durum wheat and its frequency increased up to 100% after seven rejuvenation cycles. The number of bread‐wheat genotypes identified in each entry varied from five to 13, but only a few prevailed and these were different in each accession. In most cases, bread wheat was already present in the field sample collected, but at low frequency. In one case, ‘seed flow’ was thought to have occurred at a very low rate among neighbouring plots. The implication of these findings for genetic resources conservation are: 1. Mixtures of wheat species within the same germplasm accession must be avoided; 2. Only in some cases are low planting densities effective in reducing competition; and 3. The genetic structure of accessions in the gene banks must be monitored.
Polymorphism of two waxy proteins in the emmer group of tetraploid wheat, Triticum dicoccoides, T. dicoccum, and T. durum
Authors: Yamamori M. , Nakamura T. , Nagamine T. 
Published: April 2006

AbstractGel‐electrophoretic analyses detected polymorphism of two waxy (Wx) proteins, Wx‐Al and Wx‐Bl, in 334 accessions of the emmer group of tetraploid wheat, Triticum dicoccoides, T. dicoccum and T. durum. The null allele for the Wx‐Al protein (Wx‐Alb) was found in one accession of T. dicoccoides and seven of T. dicoccum, but it was not present in those T. durum accessions analysed. The null allele for the Wx‐Bl protein (Wx‐Blb) did not occur in three emmer‐wheat species. Wx‐Al and Wx‐Bl proteins showing alteration in mobility in SDS‐PAGE gel or in isoelectric points were found in five accessions and considered to be the products of new alleles, Wx‐Ald, Wx‐Ale and/or Wx‐Bld. Densitometric analysis of Wx protein bands revealed that Wx‐Al was present in smaller amounts than Wx‐B1 in almost all accessions.
Cytogenetic analysis of a long‐term Triticum timopheevii (Zhuk.) Zhuk. cell suspension culture
Authors: Zorinyants S. E. , Nosov A. V. , Badaeva E. D. , Smolenskaya I. N. , Badaev N. S. 
Published: April 2006

In vitro culturing of plant cells can cause changes in karyotype. Chromosome variations following long‐term propagation in suspension culture of Triticum timopheevii (Zhuk.) Zhuk. were studied by routine staining and C‐banding. The culture was highly heterogeneous with respect to the number and structure of chromosomes. The modal class cells had a lower chromosome number than T. timopheevii (2n= 28). This data was confirmed by cytophotometric analysis of nuclear‐DNA content. Frequencies of chromosome loss varied for different homoeologous groups. At genome chromosomes tended to be preferentially eliminated in cells of different ploidy levels.Deletions, insertions, translocations, telocentric chromosomes, isochromosomes and dicentrics and their derivatives were observed in cultured cells. Chromosomes of various homoeologous groups differed in the frequencies and spectra of re—arrangements, but most aberrations occurred in the G‐genome chromosomes. In vitro chromosome modifications did not correspond to in vivo variation. Presumably, this difference was caused by differences in the mechanisms of adaptation to the environment at the levels of the cell and the whole organism. G‐genome chromosomes were more frequently involved in this process, both in vivo and in vitro.
Breeding value of base populations derived from ‘contiguous’ clusters in perennial ryegrass
Authors: Charmet G. , Debote B. 
Published: April 2006

AbstractFive broad‐based breeding populations were produced by polycrossing natural populations sampled in five clusters developed by a hierarchical method with a geographic‐contiguity constraint. As a result, each of these breeding populations originates from a single region and the populations within a cluster are more likely to share the same alleles with similar frequencies. A single generation of intercrossing would therefore be sufficient to establish a panmixia equilibrium.These populations were tested for dry‐matter yield in plots and compared to control cultivars in two locations. There were some trends of specific adaptation related to the geographic origin of populations, which, on average, compared well to controls. Their half‐sib families were evaluated as spaced plants in one location. This allowed genetic parameters and expected response to selection to be computed. Three out of five breeding populations appeared to be promising for the development of new, improved synthetic varieties.
Heterosis and combining ability in hybrids among 12 commercial varieties of sesame (Sesamum indicum L.)
Authors: Quoada P. , Layrisse A. 
Published: April 2006

AbstractHeterosis and combining‐ability effects were studied in the parents and 66 F1 hybrids from a diallel cross of 12 elite sesame varieties in five different environments in Venezuela. The mean yield of the hybrids was clearly superior to the parental mean in all five locations. There were three heterotic hybrids that showed a higher yield than controls in all environments. The best hybrid in each place yielded significantly better than the best cultivar, the differences ranging from 28 to 109%. Specific combining‐ability (SCA) effects were more important than general combining‐ability (GCA) in four of the environments. A large genotypexlocation interaction was found for all traits, suggesting that hybrids should be produced for specific locations. ‘Arawaca’ and ‘Piritu’ should be chosen as parents for any sesame‐breeding programme in view of their large GCA effects.
Inheritance of resistance to Karnal bunt (Tilletia indica Mitra) in bread wheat (Triticum aestivum L.)
Authors: Fuentes‐Davila G. , Rajaram S. , Singh G. 
Published: April 2006

AbstractThe mode of inheritance and allelic relationships among genes conferring resistance to Karnal bunt were studied in seven bread‐wheat (six resistant and one susceptible) genotypes. The resistant genotypes originated in China (‘Shanghai#8’), Brazil (PF71131), the USA (‘Chris’), and Mexico (‘Amsel’, CMH77.308 and ‘Pigeon’). The susceptible line WL711 was from India. Evaluation of these wheat lines and all possible crosses among their F1 and F3 generations (about 100 progenies in each cross) revealed that two partially recessive genes conferred the resistance to Karnal bunt in ‘Pigeon’, whereas four partially dominant genes were present in the other genotypes. ‘Chris’, ‘Amsel’ and PF71131 carry one gene, whereas ‘Shanghai#8’ and CMH77.308 have two genes. ‘Chris’, ‘Amsel’, and PF71131 have different genes, whereas one gene was common to PF71131, CMH77.308 and ‘Shanghai#8’, and another to ‘Chris’ and CMH77.308. Gene symbols were formally designated to the resistant stocks. Resistance was incomplete and stable.
Effect of chromosome‐doubling agents on somaclonal variation in the progeny of doubled haploids of maize
Authors: Wan Y. , Widholm J. M. 
Published: April 2006

AbstractThis study was carried out to determine whether the treatment of anther‐culture‐derived haploid callus of maize (Zea mays) with chromosome‐doubling agents, such as colchicine or the herbicides pronamide and amiprophos‐methyl (APM), induces higher than normal levels of somaclonal variation. A total of 79 R1 families produced by diploid regenerated plants resulting from chromosome‐doubling treatments were evaluated in the field in comparison with the three parental inbreds.Four qualitative variant phenotypes — male sterility, chlorophyll deficiency, earless plants, and short plants with narrow leaves and thin stalks —– were observed. The last phenotype (narrow leaves and thin stalks) was also found in the inbreds FR16 and H99 grown from seed, so it may not be directly related to the tissue‐culture conditions or the anti‐microtubule‐agent treatments. The frequency of R1 families segregating for the other three mutations was 3.8%, which is no higher than the somaclonal variation frequencies observed previously in tissue‐culture‐derived maize plants. Observations of three quantitative traits—–days to anthesis, days to silk emergence, and plant height—– also failed to detect any extra variation that could be related to the treatments with anti‐microtubule agents. These studies indicate that the anti‐microtubule agents APM, pronamide and colchicine can be used to induce chromosome doubling of anther‐culture‐derived callus to produce a high proportion of doubled haploid plants without causing increased rates of mutation (somaclonal variation).
Anther‐Culture ability in Secale cereale L.
Authors: Fleinghaus‐Roux T. , Deimling S. , Geiger H. H. 
Published: April 2006

AbstractSuccess in anther culture of rye (Secale cereale L.) has mainly been restricted to genotypes whose genome is partly determined by S. vavilovii Grossh. The aim of this study was to identify true S. cereale genotypes with anther‐culture ability. The plant material used included the semi‐wild standard genotype SC35, six single crosses of the ‘Petkus’ and 10 of the ‘Carsten’ gene pool, plus a double cross between SC35 and one of the ‘Carsten’ single crosses. Three anther‐culture experiments were performed. Several single crosses within the ‘Carsten’ gene pool produced green plants. The ‘Petkus’ single crosses tested did not show anther‐culture ability. As expected, the induction and regeneration rates of SC35 were higher than those of all other genotypes tested. The performance of the double cross was intermediate between its parents. The results demonstrate for the first time that anther culture in rye is a valuable tool in plant breeding. The data also show the possibility of transferring anther‐culture ability from high‐ to low‐responding genotypes.
Comparison of predicted and observed response to selection in two breeding populations of perennial ryegrass
Authors: Ravel C. , Charmet G. , Balfourier F. , Debote B. , Vézine J. C. , Astier C. 
Published: April 2006

AbstractTo predict any genetic response to selection, two breeding populations of perennial ryegrass, consisting of half‐sib families, were evaluated as spaced plants from 1987 to 1989 for several agronomical traits. In each population, the best plants selected through a multitrait Smith and Hazel's index were planted in a polycross to produce the second generation half‐sib families. Both generations were evaluated together from 1991 to 1993 as spaced plants. The difference between generations was the observed genetic response, which was compared to that predicted. Rust tolerance, aftermath heading and persistence were significantly improved in both populations. In trial plots used to assess the yield, no effect of mass selection was noticed. Thus, it is concluded that mass selection failed to increase productivity but produced some improvements in disease tolerance and aftermath heading.
Powdery‐mildew‐resistance genes Mla29 and Mla32 in H. spontaneum derived winter‐barley lines
Authors: Kinizios S. , Jahoor A. , Fischbeck G. 
Published: April 2006

AbstractAllelism to the highly polymorphic Mia locus was demonstrated for the powdery‐mildew resistance of two Hordeum spontaneum derived winter–barley lines, ‘110‐4 × Sonja’ and ‘142–29 × Dura’, by testing the F2 progeny of crosses between these lines and the winter‐barley cv. ‘Triton’ (Mlal3) with two appropriate isolates. The results were confirmed by RFLP analysis, using the probe MWG 1H036, which is very closely linked to the Mia locus. The designations Mla29 and Mla32 are proposed for the genes identified in the two lines.
Unreduced gamete in interspecific hybrids in the Festuca/Lolium complex
Authors: Morgan W. G. , Thomas H. , Hanumphreys M. W. 
Published: April 2006

AbstractSelf‐sterile interspecific hybrids between diploid Lolium perenne and either Festuca arundinacea or F. gigantea (both hexaploids) set some seeds when subjected to a heavy pollen cloud from the amphiploids derived from the hybrids. All the progeny were octoploid and were formed from the fertilization of unreduced gametes in the F1 hybrid by amphiploid pollen. The significance of the results in relation to breeding efforts within the Lolium/Festuca complex is discussed.