Biometrische Auswertung von Rückkreuzungsserien in genetisch weiten Kreuzungen bei Sommergerste

Wildformen können zur Verbreiterung der genetischen Basis und zur Verbesserung qualitativer und vermutlich auch quantitativer Merkmale beitragen. Unerwünschte Eigenschaften der Wildformen zwingen den Züchter zu aufwendigen Rückkreuzungen. Zielsetzung der vorliegenden Arbeit ist eine Untersuchung der Vererbung quantitativer Merkmale in genetisch weiten Rückkreuzungsserien, die Anwendung der gewonnen Erkenntnisse zur optimalen Ressourcenallokation, sowie eine Evaluierung des Potentials der Wildformen zur Verbesserung quantitativer Merkmale. Hierzu wurden beispielhaft quantitative Merkmale in Rückkreuzungsserien (BC1 BC4) in dreißig Kreuzungskombinationen eines unvollständigen Kreuzungsfaktoriells aus H. vulgare ssp. vulgare x H. vulgare ssp. spontaneum untersucht. Anhand der in zweijährigen Feldversuchen gewonnen Daten, wurden die allgemeine und spezifische Kombinationseignung, die Eigenleistung der Eltern und der Kreuzungsnachkommen, die Entwicklung der Mittelwerte und Varianzen in den Rückkreuzungsserien im Vergleich zu theoretischen Modellen und die positive Transgression der Nachkommen im Merkmal Karyopsenertrag untersucht Kombinationseignungen und Elterneigenleistungen können bedingt zur Auswahl der Kultur-, nicht aber der Wildeltern oder einzelner Kreuzungskombinationen genutzt werden. Die Mittelwerte der Nachkommen entwickelten sich meist von der BC1 zur BC4 in Richtung der rekurrenten Eltern. Korrelationen zwischen den Generationen ergaben vor allem für Merkmale hoher Heritabilität straffe sehr hoch signifikante Beziehungen. Die Variabilität konnte durch die Kreuzung mit den Wildgersten erhöht werden, die Beziehungen der Varianzen zwischen den Rückkreuzungsgenerationen waren schwach, z.T. negativ und selten signifikant. Die Übereinstimmung der theoretischen Modelle mit den Mittelwerten und Varianzen war unzureichend, um Prognosen später Rückkreuzungsgenerationen zu empfehlen. Zur Erklärung der Abweichungen der empirischen Werte von den Modellen mussten epistatische Effekte herangezogen werden. In den Nachkommenschaften aller verwendeten Wildformen konnten für den Karyopsenertrag positiv transgressive Linien, d.h. Linien deren Ertrag zwei Standardabweichungen größer als der der Kultureltern war, gefunden werden. Der Anteil war in der BC3/BC4 am höchsten. Wildformen sind zur Verbesserung auch züchterisch intensiv bearbeiteter quantitativer Merkmale und zur Erhöhung der Variabilität geeignet. Um die notwendige Erhöhung der genetischen Diversität zu sichern, sollten künftig Prebreedingstrategien und der Kombination klassischer und markergestutzter Verfahren bei der Nutzung von Wildformen mehr Aufmerksamkeit gewidmet werden.Biometrical analysis of a series of backcrosses in genetically wide crosses with spring barley Wild genotypes can be used to broaden the genetic basis and improve qualitative and probably quantitative traits. The plant breeder is forced to perform tedious backcrosses to eliminate undesirable traits originating from the wild genotypes. The aim of the current study is to investigate the inheritance of quantitative traits in genetically wide crosses, make use of the results for an optimal allocation of resources and to evaluate the potential of the wild genotypes to improve quantitative traits. Quantitative traits were analysed in four backcross generations (BC1 - BC4) developed from thirty crosses between H. vulgare ssp. vulgare x H. vulgare ssp. spontaneum in an incomplete factorial mating design. Based on the data collected in two years of field trials the general and specific combining ability, the performance of the parents and progeny, the development of the means and variances compared to theoretical models and the positive transgression of the trait grain yield were investigated. Results show that the combining abilities and the performance of the parents may be used to choose suitable parents from the cultivated genotypes but not to select promising wild genotypes or specific crosses. The means of the progeny grow closer to the means of the cultivated parents from the BC1 to the BC4. The results of correlations between the generations show highly significant relationships especially if traits with a high heritability are concerned. The variability increased by crossing with wild genotypes. The relationship between variances in backcross generations was weak, sometimes negative and hardly ever significant. The theoretical models did not correspond well to the means and variances. A prognosis based on the theoretical models can not be recommended. Epistatic effects were necessary to explain the deviations of the empirical values from the theoretical models. It was possible to find positive transgressive progeny for the trait grain yield in the offspring of every wild genotype. Positive transgression was defined as a grain yield at least two standard deviations higher than that of the cultivated parent. The percentage of transgressive lines was highest in the BC3/BC4. The results of this study show that wild genotypes have the potential to improve quantitative traits that have been subjected to intensive breeding as well as to increase the variability of the progeny. To safeguard genetic diversity prebreeding strategies and strategies comprising classical as well as marker based methods should be taken into consideration when utilizing wild genotypes in plant breedin

Peak oil: will it be public health's greatest challenge?

The health of populations is determined more by the social and economic determinants of health than by changes in technology, health services or short-term policy interventions. In the near future, there is likely to be a significant shortfall in energy supply, resulting in high energy prices and a reversal of many of the aspects of globalization that are currently taken for granted. If this happens, economic recession and restructuring could have a negative impact on health, not dissimilar to that experienced by the former Soviet Union when it attempted a rapid change in its economy. There is, however, the potential, through economic planning and sustainable development, to reduce the adverse effects of this change and use this opportunity to impact on a range of diseases which are, at least in part, caused by overconsumption, inequality and loss of community

Data Driven Marketing : a presentation of opportunities and challenges for companies

In der vorliegenden Bachelorarbeit werden die Chancen und Risiken des Data Driven Marketings (DDM) untersucht. Die zugrunde liegende Forschungsfrage lautet " Inwiefern beeinflusst datengetriebenes Marketing die Geschäftsentwicklung von Unternehmen und welche spezifischen Chancen und Risiken ergeben sich aus dessen Einsatz?

Theoretical investigation of orbital alignment of x-ray-ionized atoms in exotic electronic configurations

We theoretically study orbital alignment in x-ray-ionized atoms and ions, based on improved electronic-structure calculations starting from the Hartree-Fock-Slater model. We employ first-order many-body perturbation theory to improve the Hartree-Fock-Slater calculations and show that the use of first-order-corrected energies yields significantly better transition energies than originally obtained. The improved electronic-structure calculations enable us also to compute individual state-to-state cross sections and transition rates and, thus, to investigate orbital alignment induced by linearly polarized x rays. To explore the orbital alignment of transiently formed ions after photoionization, we discuss alignment parameters and ratios of individual state-resolved photoionization cross sections for initially neutral argon and two exotic electronic configurations that may be formed during x-ray multiphoton ionization dynamics induced by x-ray free-electron lasers. We also present how the orbital alignment is affected by Auger-Meitner decay and demonstrate how it evolves during a sequence of one photoionization and one Auger-Meitner decay. Our present work establishes a step toward investigation of orbital alignment in atomic ionization driven by high-intensity x rays

State-resolved ionization dynamics of a neon atom induced by x-ray free-electron-laser pulses

We present a theoretical framework to describe state-resolved ionization dynamics of neon atoms driven by ultraintense x-ray free-electron-laser pulses. In general, x-ray multiphoton ionization dynamics of atoms have been described by time-dependent populations of the electronic configurations visited during the ionization dynamics, neglecting individual state-to-state transition rates and energies. Combining a state-resolved electronic-structure calculation, based on first-order many-body perturbation theory, with a Monte Carlo rate-equation method enables us to study state-resolved dynamics based on time-dependent state populations. Our results demonstrate that configuration-based and state-resolved calculations provide similar charge-state distributions, but the differences are visible when resonant excitations are involved, which are also reflected in calculated time-integrated electron and photon spectra. In addition, time-resolved spectra of ions, electrons, and photons are analyzed for different pulse durations to explore how frustrated absorption manifests itself during the ionization dynamics of neon atoms