bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phenotypic differences in transgenic plants of chrysanthemum
Authors: Benetka V. , Pavingerová D. 
Published: April 2006

AbstractPhenotypic deviations in transgenic plants of chrysanthemum (Dendranthema grandiflora Tzvelev.) cv. ‘White Snowdon’ carrying either whole pTiB6S3 T‐DNA or the GUS gene construct were evaluated. Morphological differences in comparison with the controls were observed not only in regenerated transgenic plants carrying Agrobacterium tumefaciens B6S3 T‐DNA, but also in transgenic plants carrying the GUS gene. The phenotypic changes were stable through several cycles of clonal propagation.
Phenotypic expression of quantitative and qualitative components of partial resistance to powdery mildew (Sphaerotheca fuliginea race 1) in melon (Cucumis melo) germplasm
Authors: Boiteux L. S. , Reifschneider F. J. B. , Pessoa H. B. S. V. 
Published: April 2006

AbstractA study was conducted to investigate the expression of four components of partial resistance to Sphaerotheca fuliginea race 1 in selected melon (Cucumis melo L.) lines viz. infection frequency, latent period, spore production, and disease‐severity score. Those components were evaluated at two developmental stages of the host: the cotyledon stage and the stage of the first two true leaves. Detached plant parts (disks of cotyledons and true leaves) were inoculated using a vacuum‐operated settling tower. All four components showed significant variation among genotypes, and correlations between components at both developmental stages were large and significant. The line ‘CNPH 83–095’ (without any major resistance gene to powdery mildew) presented the highest level of partial resistance in both vegetative stages for almost all components evaluated. The lines ‘W‐6’ (Pm1Pm1, Pm2Pm2), ‘Cinco’ (Pm1Pm1, Pm2Pm2), and CNPH ‘84–147’ (Pm1Pm1), even though carrying the major gene Pm1 for complete resistance to race 1 of the fungus, showed slight but significant differences for quantitative components of partial resistance at the cotyledonal stage. Different levels of partial resistance may be expressed, even in lines with a major race‐specific resistance gene to powdery mildew, in specific developmental stages of the melon plants.
Purity control of F1‐hybrid tomato cultivars by RAPD markers
Authors: Rom M. , Bar M. , Rom A. , Pilowsky M. , Gidoni D. 
Published: April 2006

AbstractRandomly amplified polymorphic DNA (RAPD) markers were applied in purity control of hybrid seed production of tomato (Lycopersicon esculentum Mill.). DNA from three commercial F1‐hybrid cultivars and their parental lines was subjected to RAPD screening with 50 primers. Two of four primers which detected polymorphism between the parents tested, generated paternal‐specific RAPDs, enabling a clear distinction to be made between hybrids and their maternal parents. In addition, combination of the polymorphic DNA products generated by these primers exhibited hybrid‐specific patterns, enabling each cultivar to be identified. This result indicates the practical usefulness of RAPD markers in hybrid‐tomato‐seed purity‐control tests and cultivar identification.The approach is advantageous in its rapidity and simplicity, particularly as an alternative for those cultivars for which lengthy and costly phenotypic tests are currently used.
Selection in vitro for erucic‐acid content in segregating populations of microspore‐derived embryoids of Brassica napus
Authors: Albrecht S. , Möllers C. , Röbbelen G. 
Published: April 2006

AbstractMicrospore culture of Brassica napus under optimized conditions leads to the regeneration of microspore‐derived embryoids that, at the late cotyledonary stage, contain large amounts of storage lipids, equal or similar in composition to those found in seeds of the homozygous donor plants. At that stage, the microspore‐derived embryoids are large enough to allow the dissection of one cotyledon under aseptic conditions and the determination of its fatty‐acid composition. The remaining part of the embryoid can be cultured further and regenerated to give a plant. This offers the possibility of early selection for fatty‐acid composition in segregating populations of microspore‐derived embryoids. In order to verify this hypothesis, embryoids were generated from microspores of F| plants derived from a cross between doubled haploid lines of the low‐erucicacid cv. ‘Duplo’ and the high‐erucic‐acid cv. ‘Janetzki’. The contents of eicosenoic acid (C20: 1) and erucic acid (C22: 1) in the cotyledons and in the seeds derived from plants regenerated from the remaining parts of the embryoids were highly correlated (rs = 0.85**, P = 0.01). This indicates that, in breeding programmes for high erucic acid, the majority of the microspore—derived embryoids can be discarded at an early stage in vitro. Only microspore‐derived embryoids with a high content of C20: 1+C22:1 in the cotyledons need to be transferred to the greenhouse. This report also deals with the addition of abscisic acid (ABA) to the embryoid culture medium to increase the correlation, and discusses the possible application of this system for the selection of high‐oleic or low‐linolenic types in corresponding microspore‐derived embryoid populations.
Spontaneous and induced chromosome doubling in gynogenic lines of onion (Allium cepa L.)
Authors: Campion B. , Perri E. , Azzimonti M. T. , Vicini E. , Schiavi M. 
Published: April 2006

AbstractThe presence of 2,4‐dichlorophenoxyacetic acid (2,4‐D) or naphthaleneacetic acid (NAA) and 6‐benzyladenine (6—BA) in the medium is required to induce an acceptable yield of gynogenic embryos from unfertilized ovary and flower cultures in onion. Four different exposure times of ovary and flower cultures to exogenous growth regulators (15, 30, and 45 days, and the entire culture period) were assayed. The objective was to ascertain the effect of these substances and of their period of application on the formation of gynogenic embryos and on the yield of haploids. An exposure of 15 days was sufficient for ovaries and flowers to be stimulated towards the gynogenic response, whereas, for the remaining period of 30—80 days, the pro‐embryos could easily grow on a growth‐regulator‐free medium. In the gynogenic material obtained, phenotypic differences were visible between genetically independent lines but not between plants within each line, even when they had a different ploidy level (n or 2n). Almost all lines obtained by gynogenesis were sterile. Only a small percentage (1%) became fertile through spontaneous chromosome doubling, and these produced 2—20 seeds each, giving normal plants. The recovery of fertility occurred more often during the generations of bulbils. To exploit this natural propensity towards diploidization in this phase, different amounts and numbers of applications of colchicine were evaluated in two experiments. The treatments corresponding to 10 and 100 mg/1 of colchicine applied for 24h gave the highest number of diploid cells in root tips but no diploidization occurred in the shoot apices. Three days of colchicine treatment at 10 mg/1 produced 46% of plants completely diploid in the shoot apex. The flower fertility of these doubled haploid plants is being evaluated.
Genetic analysis for haploid‐regenerations responses of the hexaploid‐wheat anther cultures
Authors: Moien A. , Sarrafiu A. 
Published: April 2006

AbstractGenetic variability in response to anther culture was investigated in 49 winter hexaploid wheats, comprising 33 pure lines (F10) derived from a composite cross programme and their 16 parental genotypes. All genotypes were grown in a randomized block design with three replications in a controlled greenhouse. The number of embryoids and total plant regeneration per 100 anthers, as well as the numbers of green and albino plants regenerated per 100 embryoids, were measured.Significant genetic variability was observed among the 49 genotypes for all the traits studied. All traits showed high heritability. Among the genotypes compared, DC230N and 1BPT‐40 gave the best results for the production of embryoids and IBPT‐78 had the highest value for the production of green plants.The genotype IBPT‐34 developed a large number of albino plants, and it should be useful as a parent in studies to determine the genetic control of albino plants in wheat.
Types and components of resistance to Fusarium head blight of wheat
Authors: Mesterházy A. 
Published: April 2006

AbstractResistance of wheat to Fusarium head blight caused by Fusarium graminearum and F. culmorum was identified in natural epidemics in 1985 and 1987 as well after artificial inoculations (1983–1988 and 1984–1987). Out of 25 genotypes tested, five were identified with no significant difference in head blight scores, but differing significantly in yield after artificial inoculation, i.e. tolerance differences were detected at different resistance levels. Some genotypes that were similar in yield or head blight scores differed in seed infection severity. Genotypes with awns were more susceptible to head blight when tested under natural epidemic condition in the field; but this trait did not influence head blight severity in artificial inoculations. Dwarf genotypes were more severely infected by head blight than tall genotypes under natural conditions, but genotypes of different plant height classes were similarly susceptible after artificial inoculations. In the early generations of a breeding programme resistance measured by visual evaluation of artificial inoculation is the most important way to screen. If selection of dwarf and awned genotypes cannot be avoided, the higher susceptibility caused by awns and dwarfness under natural epidemic conditions can be decreased by a higher level of physiological resistance, as variability in physiological resistance is available. In later generations, traits like percentage of seed infection or tolerance can be identified by additionally measuring yield reduction. Stability of disease reaction appears to be connected with resistance level, the most resistant genotypes are the most stable, and the most susceptible ones tend to have more unstable reactions in different epidemic conditions.
Genetic analysis of powdery‐mildew resistance of a winter‐wheat line, RE714, and identification of a new specific‐resistance gene
Authors: Robe P. , Doussinault G. 
Published: April 2006

AbstractThe winter‐wheat line RE714, resulting from an intergeneric cross between Aegilops squarrosa and Triticum dicoccum, and implying a sister line of ‘Roazon’ (VM4) in its genealogy, was obtained in order to increase the genetic diversity for disease resistance. The aim of this study was to identify and characterize the powdery‐mildew‐resistance gene(s) present in this line at the seedling stage on detached leaves. The comparison of the reaction of the RE714 line and of differential hosts to 24 Erysiphe graminis. f.sp. tritici isolates indicated that only Pm4a, Pm4b and/or Mlar genes could be present and that a new resistance factor, different from all known mildew‐resistance genes, was present in this line. The powdery‐mildew reactions of segregating F2 populations produced evidence that RE714 carries the Pm4b allelic form and a recessive new resistance gene, tentatively designated mlre. While Ae. squarrosa was resistant to most isolates, T. dicoccum was specifically attacked by REV 14‐virulent isolates and was therefore assumed to be the donor of mire. The VM4 parent was confirmed as the Pm4b donor.
Rht1(B. dw), an alternative allelic variant for breeding semi‐dwarf wheat varieties
Authors: Worland A. J. , Sayers E. J. 
Published: April 2006

AbstractThe vast majority of the world's acreage of semi‐dwarf wheat varieties is at present cultivated with varieties carrying one of two genetically similar dwarfing genes, Rht1 and Rht2, derived from the Japanese variety ‘Norin 10’. Near‐isogenic lines have been developed and tested to determine the breeding potential of an allelic variant of Rht1, designated Rht1(B. dw).Following its introduction into four varietal backgrounds, Rht1 (B. dw) was seen to reduce height by around 25%, to increase the number of grains setting in spikelets and ears by around 20%, to reduce grain weight by 10%, and to increase yields of plants grown under spaced or drilled conditions by about 8%.When compared to the commercially utilized Rht1 allele, as near isogenic lines in a ‘Mercia’ varietal background, Rht1 (B. dw) gives a significantly greater reduction in plant height, a greater increase in spikelet and ear fertilities, slightly less reduction in 1000‐grain weight, and significantly higher spikelet, ear and plot yields. If these results are repeatable in other varietal backgrounds, over seasons, and under differing environmental conditions, Rht1 (B. dw) should have considerable commercial potential as an alternative allele for producing shorter‐than‐average, high‐yielding, semi‐dwarf wheat varieties.
Resistance to viruses in F1hybrids produced by direct crossing between diploidSolanumseriesTuberosaand diploidS. brevidens(seriesEtuberosa) usingS. phurejafor rescue pollination
Authors: Valkonen J. P. T. , Orrillo M. , Slack S. A. , Plaisted R. L. , Watanabe K. N. 
Published: April 2006

AbstractResistance to potato viruses was examined in the F1hybrids (TET) obtained from a cross between a diploid (2n = 24), tuber‐bearing interspecific hybrid 87HW13.7 (Solanum tuberosumW231 ×S. multi‐dissectumPI 473354) and a diploid (2n = 24), nontuber‐bearing wild potato species (S. brevidensCPC 2451) usingS. phurejaIvP35 (2n = 24) for rescue pollination. The parental plants were susceptible to PVX, whereas two hybrids (TET38.2 and TET38.9) andS. phurejaIvP35 reacted with hypersensitivity to PVX. Two hybrids (TET 38.9 and TET 38.12) were extremely resistant to PVY°, which was similar toS. brevidensandS. phurejaIvP35, whereas the remaining two hybrids were moderately resistant to PVY°. No resistance to PVA and PLRV was observed in the progenies, in contrast toS. brevidenswhich was extremely resistant to PVA and PLRV. Hypersensitivity to PVX in two progenies suggested (1) integration by somatic translocation or heterofertilization and expression of genes from the rescue pollinatorS. phurejaIvP35, or (2) transgressive or complementary gene action.
Molecular markers and protein quantities as genetic descriptors in maize. II. Prediction of performance of hybrids for forage traits
Authors: Burstin J. , Charcosset A. , Barriére Y. , Hébert Y. , de Vienne D. , Damerval C. 
Published: April 2006

AbstractAs it is related to the variability in genome expression, variability in protein quantities revealed by two‐dimensional electrophoresis was proposed for describing phenotypic diversity. The objective of this study was to compare the predictive power of different genetic distances derived from molecular markers and from protein quantitative variations in a diallel of 210 hybrids among 21 maize inbred lines (Zea mays L.) of various origin. The lines were characterized for: 1. 142 markers resulting from the analysis of enzyme, RFLP, and protein‐structure polymorphism; and 2. The variation in relative quantities of 190 proteins. The hybrids were evaluated for six forage traits in four environments. Correlations between the genetic distances computed for 142 marker loci and hybrid performances were moderate to high in diallels using crosses between related lines. Genetic distances based on protein quantities showed, in most cases, similar or lower correlations. Distance measures were not useful as predictors of hybrid performance for crosses between unrelated lines. Protein quantities were better for revealing specific genotypes.
A stable cytoplasmic male‐sterile line of Brassica juncea carrying restructured organelle genomes from the somatic hybrid Trachystoma ballii+B. juncea
Authors: Kirti P. B. , Mohapatra T. , Baldev A. , Prakash S. , Chopra V. L. 
Published: April 2006

AbstractA cytoplasmic male‐sterile (CMS) line of Brassica juncea has been developed by combining the cytoplasm originating from the somatic hybrid Trachystoma ballii+B. juncea, and the nucleus of B. juncea cv. Pusa Bold by repeated backcrossing. Male‐sterile plants closely resembled the normal fertile B. juncea in general morphology, but had delayed flowering (5–7 days) when compared with fertile ‘Pusa Bold’ which flowered in 45 days. Stamens of the male‐sterile line were transformed into petaloid structures. Pollen abortion occurred after tetrad formation. Female fertility of the male‐sterile line was normal. Molecular analysis of organelle genomes indicated extensive mitochondrial DNA recombinations in the CMS line. Preliminary analysis of the chloroplast genome of the CMS line also indicated chloroplast DNA recombination.
Karyotype and C‐banding pattern of mitotic chromosomes in alfalfa, Medicago sativa L.
Authors: Falistocco E. , Falcinelli M. , Veronesi F. 
Published: April 2006

AbstractNumerous cytogenetic studies have been performed on alfalfa (Medicago sativa L. 2n= 4x= 32), but only a few have examined the somatic chromosomes. Because the major factor limiting the study of somatic chromosomes of M. sativa is their rather uniform morphology, characterization was attempted using the C‐banding technique instead of the traditional Feulgen method. Chromosome morphology and position of the heterochromatic bands resulted in satisfactory characterization of the chromosomes and provided further evidence of the autotetraploid origin of the species. It was possible to identify the homologous chromosomes and arrange them into eight groups of four. The ideogram of the basic genome of eight chromosomes was constructed. The impact of these results on cytogenetic studies and breeding research in alfalfa is discussed.
Genetic analysis and nomenclature for seven isozyme systems in Brassica nigra, B. oleracea and B. campestris
Authors: Chevre A. M. , Delourme R. , Eber F. , Margale E. , Quiros C. F. , Arus P. 
Published: April 2006

AbstractGeneral criteria for the assignment of names to enzyme systems, regions of activity, isozyme loci and allozymes have been lacking in crucifer species. This paper proposes a standard nomenclature for seven isozyme systems in the three diploid species of U's triangle: Brassica nigra, B. oleracea and B. campestris. Gel/electrode buffers, which provided the best resolution for seven isozyme systems, acid phosphatase (APS), aconitase (ACO), leucine aminopeptidase (LAP), 6‐phosphogluconate dehydrogenase (6 PGD), phosphoglucoisomerase (PGI), phosphoglucomutase (PGM), and triosephosphate isomerase (TPI), were proposed as standards. Isozyme genetic analysis was determined for B. oleracea and B. campestris from previous studies and by segregation of selfed progenies of heterozygous B. nigra plants. Several populations were studied and 148 allozymes at the 18 loci observed were described for the three species. Their relative mobility was studied using a pure line of oilseed rape as reference. The comparison of the different alleles within and between the species is discussed.
The 1BL/1RS chromosome translocation effect on yield characteristics in a Triticum aestivum L. cross
Authors: Villareal R. L. , del Toro E. , Mujeeb‐Kazi A. , Rajaram S. 
Published: April 2006

AbstractComparisons involving 28 random F2‐derived F6 wheat (Triticum aestivum L.) lines from the cross, ‘Nacozari’/‘Seri 82’, suggested that advanced derivatives with the 1BL/1RS chromosome translocation possess superior agronomic performance in both full and reduced irrigation conditions when compared with 1B derivatives. This performance advantage was attributed to high grain yield, above‐ground biomass at maturity, grains/spike, 1000‐grain weight and test weight. The 1BL/1RS lines were shorter with delayed flowering and maturity. The superiority of the 1BL/1RS translocation group on grains/m2 was expressed only under the full irrigation environment. Higher harvest index, longer spike‐length and grain‐filling period were detected only under reduced irrigation conditions. A significant grain yield relationship with test weight was detected only among the 1BL/1RS genotypes, indicating that they possess heavier and plumper grains than the 1B genotypes.
Genetic variability in antibiotic resistance to the greenbug Schizaphis graminum in Hordeum chilense
Authors: Castro A. M. , Martían L. M. , Dixon A. F. G. 
Published: April 2006

Abstract Hordeum chilense (Roem. et Schult), a native grass of South America, is a source of antixenotic and antibiotic resistance to the greenbug Schizaphis graminum Rondani. The genetic and environmental components of the variability in antibiotic resistance shown by H. chilense were determined by measuring the developmental time, the length of adult life, fecundity and intrinsic rate of population increase of green‐bugs reared on this host. The aphids belonged to a clone of biotype C. Plants were cloned to reduce the incidence of environmental variability.Different plant characters appeared to prolong aphid developmental time and reduce the length of adult life and total fecundity. The broad sense heritability and the genetic variability of these plant characters were different. The plant character that affected aphid development appears to differ from that affecting fecundity.
Optimization of DNA amplification fingerprinting techniques to study genetic relationships of white lupin germplasm
Authors: Qiu J. , van Santen E. , Tuzun S. 
Published: April 2006

AbstractDNA amplification fingerprinting (DAF) techniques were used to evaluate genetic relationships among 24 randomly selected white lupin (Lupinus albus L.) accessions originating from four endemic regions. Parameters affecting DAF were optimized to obtain high resolution and reproducible banding patterns. DNA amplification was tolerant to a wide range of both template and primer concentrations but sensitive to Mg2+ concentration, and annealing temperature and time. Pure template DNA was found to be essential for obtaining reproducible banding patterns. Primer annealing occurred at multiple sites, permitting detection of polymorphism using only a single primer. Of 56 octamer primers tested, 22 yielded highly polymorphic DAF bands that could be used to distinguish closely related accessions. Genetic similarity coefficients were calculated and a dendrogram, using the unweighted pair group method with arithmetic average (UPGMA), was constructed. A high level of genome diversity was found among the accessions, but several from the Middle East and West Africa tended to cluster together. The results support the future use of DAF markers for the characterization and identification of white lupin germplasm.
The incompatibility system in Italian red chicory (Cichorium intybus L.)
Authors: Varotto S. , Pizzoli L. , Lucchin M. , Parrini P. 
Published: April 2006

AbstractAs a result of an incompatibility mechanism which prevents both self‐fertilization and intermating between plants with identical genotypes, inbreeding does not occur in Cichorium intybus. This self‐incompatibility system complicates the production of inbred lines and the generation of F1 hybrids in Italian red chicory.Histological observations on pollinated stigmas show that the incompatibility reaction in chicory is very rapid and either prevents pollen adhering to the stigmatic papillae or determines the arrest of pollen‐tube growth on the stigmatic surface; incompatible pollen cannot reach the transmitting tissue of the style.Both histological and genetic analyses of F1 progeny from a reciprocal cross between two unrelated plants suggest the occurrence of a sporophytic incompatibility system in Italian red chicory.