298 research outputs found

    Genetic diversity and relationships in local varieties of eggplant from different cultivar groups as assessed by genomic SSR markers

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    [EN] Spain is a secondary center of diversity for eggplant (Solanum melongena). Spanish landraces of eggplant are normally classified in four cultivar groups: Round, Listada de Gandía, Semi-Long, and Long. We have used 19 genomic SSRs for the molecular characterization of 30 eggplant accessions corresponding to the four cultivar groups. Sixteen SSRs of which 15 were polymorphic could be amplified and 65 polymorphic alleles, with a range of two to 11 alleles/locus, were detected. The polymorphism information content (PIC) of SSR markers ranged from 0.07 to 0.77, with an average value of PIC=0.50. The mean observed heterozygosity (Ho) presented a very low value Ho=0.01, while the mean expected heterozygosity (He) had a value of He=0.57. Multivariate cluster analyses revealed that a considerable diversity exists within each of the cultivar groups. Listada de Gandía and Long cultivar groups were clearly separated from each other in different branches of phenogram. The principal coordinates analysis (PCoA) confirmed that each of the cultivar groups is genetically diverse and, with the exception of the Round group, they plot in different areas of the PCoA graph. Overall, the results indicate that Spanish eggplant landraces present a high degree of homozygosis, considerable intra-cultivar group diversity, and a certain degree of genetic differentiation. This information is of interest for selection and breeding of eggplant as well as for germplasm conservation.This research has been partially funded by Ministerio de Economía y Competitividad and FEDER (grant AGL2012-34213) and by Universitat Politècnica de Valencia (grants SP20120681 and PAID-06-11 Nr. 2082).Vilanova Navarro, S.; Hurtado Ricart, M.; Cardona, A.; Plazas Ávila, MDLO.; Gramazio, P.; Herraiz García, FJ.; Andújar Pérez, I.... (2014). Genetic diversity and relationships in local varieties of eggplant from different cultivar groups as assessed by genomic SSR markers. Notulae Botanicae Horti Agrobotanici Cluj-Napoca. 42(1):59-65. https://doi.org/10.15835/nbha4219414S596542

    Measurement and Interpretation of Fermion-Pair Production at LEP energies above the Z Resonance

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    This paper presents DELPHI measurements and interpretations of cross-sections, forward-backward asymmetries, and angular distributions, for the e+e- -> ffbar process for centre-of-mass energies above the Z resonance, from sqrt(s) ~ 130 - 207 GeV at the LEP collider. The measurements are consistent with the predictions of the Standard Model and are used to study a variety of models including the S-Matrix ansatz for e+e- -> ffbar scattering and several models which include physics beyond the Standard Model: the exchange of Z' bosons, contact interactions between fermions, the exchange of gravitons in large extra dimensions and the exchange of sneutrino in R-parity violating supersymmetry.Comment: 79 pages, 16 figures, Accepted by Eur. Phys. J.

    A Determination of the Centre-of-Mass Energy at LEP2 using Radiative 2-fermion Events

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    Using e+e- -> mu+mu-(gamma) and e+e- -> qqbar(gamma) events radiative to the Z pole, DELPHI has determined the centre-of-mass energy, sqrt{s}, using energy and momentum constraint methods. The results are expressed as deviations from the nominal LEP centre-of-mass energy, measured using other techniques. The results are found to be compatible with the LEP Energy Working Group estimates for a combination of the 1997 to 2000 data sets.Comment: 20 pages, 6 figures, Accepted by Eur. Phys. J.

    Determination of the b quark mass at the M_Z scale with the DELPHI detector at LEP

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    An experimental study of the normalized three-jet rate of b quark events with respect to light quarks events (light= \ell \equiv u,d,s) has been performed using the CAMBRIDGE and DURHAM jet algorithms. The data used were collected by the DELPHI experiment at LEP on the Z peak from 1994 to 2000. The results are found to agree with theoretical predictions treating mass corrections at next-to-leading order. Measurements of the b quark mass have also been performed for both the b pole mass: M_b and the b running mass: m_b(M_Z). Data are found to be better described when using the running mass. The measurement yields: m_b(M_Z) = 2.85 +/- 0.18 (stat) +/- 0.13 (exp) +/- 0.19 (had) +/- 0.12 (theo) GeV/c^2 for the CAMBRIDGE algorithm. This result is the most precise measurement of the b mass derived from a high energy process. When compared to other b mass determinations by experiments at lower energy scales, this value agrees with the prediction of Quantum Chromodynamics for the energy evolution of the running mass. The mass measurement is equivalent to a test of the flavour independence of the strong coupling constant with an accuracy of 7 permil.Comment: 24 pages, 10 figures, Accepted by Eur. Phys. J.

    Study of Leading Hadrons in Gluon and Quark Fragmentation

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    The study of quark jets in e+e- reactions at LEP has demonstrated that the hadronisation process is reproduced well by the Lund string model. However, our understanding of gluon fragmentation is less complete. In this study enriched quark and gluon jet samples of different purities are selected in three-jet events from hadronic decays of the Z collected by the DELPHI experiment in the LEP runs during 1994 and 1995. The leading systems of the two kinds of jets are defined by requiring a rapidity gap and their sum of charges is studied. An excess of leading systems with total charge zero is found for gluon jets in all cases, when compared to Monte Carlo Simulations with JETSET (with and without Bose-Einstein correlations included) and ARIADNE. The corresponding leading systems of quark jets do not exhibit such an excess. The influence of the gap size and of the gluon purity on the effect is studied and a concentration of the excess of neutral leading systems at low invariant masses (<~ 2 GeV/c^2) is observed, indicating that gluon jets might have an additional hitherto undetected fragmentation mode via a two-gluon system. This could be an indication of a possible production of gluonic states as predicted by QCD.Comment: 19 pages, 6 figures, Accepted by Phys. Lett.
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