Outcrossing rate of safflower (Carthamus tinctorius L.) genotypes under the agro climatic conditions of Northern Germany

Safflower oil is considered to be one of the highest quality vegetable oils for human nutrition, containing up to 90% linoleic acid. The cultivation of safflower would enlarge the number of species to increase biodiversity and widen crop rotation. Very little effort on safflower breeding has been done in Germany. The knowledge of the pollination system is a prerequisite of efficiently designing future breeding programmes. The cross pollination rate between and within plots was investigated in Göttingen (Latitude: 51° 32' North and Longitude: 9° 57' East ) in 2004 and 2005. A plot of 10 m2 of non-spiny plants was surrounded by plots of spiny plants. Ten nonspiny plants each of the border rows and of the core were harvested individually. The rate of cross pollination was calculated as the ratio of spiny to non-spiny offsprings. The average cross pollination was 6.5% (core), 9.7% (border no.1) and 18.1% (border no. 2). In a second experiment the rate of cross pollination within plots was estimated from non-spiny plants grown in mixture with spiny plants. The outcrossing rate was about 63% in 2004, but about 30% in 2005. Isolating or covering flowers by bags or cloth should be considered in pedigree breeding

Tomaten für den ökologischen Anbau im Freiland - Züchtungsmethodik und regionale Sortenentwicklung

Tomaten sind in Deutschland das wichtigste Gemüse. Im Erwerbsanbau werden nicht einmal 10% des Bedarfs erzeugt. Ein wesentlicher begrenzender Faktor für die Ausweitung der Tomatenproduktion sind Probleme im Freilandanbau durch die Kraut- und Braunfäule (Phytophthora infestans). Ziel ist die Züchtung von Sorten für den ökologischen Anbau im Freiland. 2008 wurden die besten Zuchtlinien im Vergleich mit Standardsorten in Mittel- und Norddeutschland geprüft. Die Ergebnisse für Ertrag, Frühzeitigkeit, Ernteperiode und Fruchtqualität waren positiv. Die besten Linien decken ein Spektrum von 20-40 g Fruchtgewicht ab. Ausgewählte Sorten von „Wildtomaten“ wurden in einer für den Erwerbsgartenbau entwickelten Anbauweise demonstriert. Die Korrelation von Feldresistenz gegen Phytophthora mit niedrigem Fruchtgewicht bleibt ein begrenzender Faktor. Vier Kreuzungen „großfrüchtig / geringe Feldresistenz“ x „kleinfrüchtig / hohe Feldresistenz“ wurden in der F2- Generation analysiert. Die Korrelation von Ertrag und Fruchtgewicht war in drei Kreuzungen positiv. Die Korrelation von Fruchtzahl und Fruchtgewicht war nur in zwei Fällen negativ; Kreuzungen ohne negative Korrelation zwischen Fruchtzahl und Fruchtgewicht könnten Selektionsmöglichkeiten für ein höheres Ertragspotenzial bieten. Phytophthora-Infektionen traten witterungsbedingt unerwartet wenig auf. Daher muss in weiterführenden Untersuchungen geklärt werden, ob großfrüchtige Genotypen generell eine geringere Phytophthora-Feldresistenz aufweisen. Schäden durch die Dürrfleckenkrankheit (Alternaria solani) konnten bonitiert werden. Pre-Breeding Material zur züchterischen Bearbeitung wichtiger Eigenschaften wurde gesichert. Der züchterische Bedarf wurde mit Fachleuten aus Züchtung, Jungpflanzenproduktion, Tomatenproduktion, Naturkost Großhandel, Beratung und Saatguthandel diskutiert. Hemmnisse der Verbreitung ökologischer Sorten sind 1) das Saatgutrecht, 2) zu kleine Zuchtprogramme und 3) ungenügende Vermarktungsstrukturen

Diversity analysis of Ethiopian mustard breeding lines using RAPD markers

Ethiopian mustard (Brassica carinata A. Braun) is an oilseed crop less known to the other parts of the world. Utilization of the available germplasm of B. carinata for different breeding purposes requires information on genetic diversity. Random amplified polymorphic DNA (RAPD) was employed to characterize the genetic diversity of 22 B. carinata inbred lines derived from accessions collected from eight different geographic areas in Ethiopia and one from Sweden. Forty-three primers were used for amplification. The resulting RAPD pattern was analysed with respect to size and distribution of fragments, reproducibility, genetic diversity and informativeness of the marker for genotype specific amplification. In total, 371 bands were amplified of which 239 (65%) were polymorphic. Band size ranged from 300 to 4000 kb. The number of bands generated by each primer varied from 3 to 15 with an average of 8.6, while number of polymorphic bands varied from 1 to 12 with an average of 5.6. RAPD patterns were reliably reproducible between replicates. Genetic similarity (GS) calculated from the marker data using Jaccard`s similarity coefficient (JCS) ranged from 0.34 to 0.84. Using cluster analysis based on unweighted pair-group method with arithmetic average (UPGMA) and principal coordinate analysis (PCoA), the 21 Ethiopian inbred lines were grouped into three subgroups and the single genotype introduced from Sweden formed a separate group. The clustering pattern failed to show a clear correspondence between geographic and molecular diversities within the Ethiopian gene pool. Generally, RAPD differentiation was higher for the exotic genotype, thus formation of a gene pool distinct from the Ethiopian gene pool could be possible through introduction. Based on the genetic relatedness, selective parental combinations were earmarked as potential parents for the future breeding work. The RAPD assay generated genotype-specific products in 14 of the genotypes studied which could be used as DNA fingerprint for variety identification

Evaluierung von Saflor-Akzessionen für den Ökologischen Landbau

In Deutschland werden im Ökologischen Landbau trotz vorhandener Nachfrage nach Speiseöl nur sehr wenige Ölpflanzen angebaut. Saflor oder Färberdistel ist dabei als eine sinnvolle Alternative zu Raps bzw. Sonnenblumen anzusehen, es liegen jedoch bislang nur wenige Untersuchungen zur Anbauwürdigkeit vor. 741 Saflorherkünfte wurden 2002 auf ihre Anbaueignung unter hiesigen Klimabedingungen zweiortig geprüft. 2003 wurden 65 daraus ausgelesene, überlegene Herkünfte in einer dreiortigen Leistungsprüfung getestet. Es zeigte sich neben einer sehr großen Variabilität des verwendeten Materials, dass sich vorrangig europäische Formen durch eine gute Kornausbildung und höhere Samenerträge auszeichneten. Zwischen beiden Jahren bestand keine Beziehung in den Samenerträgen der 65 Herkünfte

Restructuring of colloidal aggregates in shear flow: Coupling interparticle contact models with Stokesian dynamics

A method to couple interparticle contact models with Stokesian dynamics (SD) is introduced to simulate colloidal aggregates under flow conditions. The contact model mimics both the elastic and plastic behavior of the cohesive connections between particles within clusters. Owing to this, clusters can maintain their structures under low stress while restructuring or even breakage may occur under sufficiently high stress conditions. SD is an efficient method to deal with the long-ranged and many-body nature of hydrodynamic interactions for low Reynolds number flows. By using such a coupled model, the restructuring of colloidal aggregates under stepwise increasing shear flows was studied. Irreversible compaction occurs due to the increase of hydrodynamic stress on clusters. Results show that the greater part of the fractal clusters are compacted to rod-shaped packed structures, while the others show isotropic compaction.Comment: A simulation movie be found at http://www-levich.engr.ccny.cuny.edu/~seto/sites/colloidal_aggregates_shearflow.htm

Extending the rapeseed gene pool with resynthesized Brassica napus II: Heterosis

Hybrid breeding relies on the combination of parents from two differing heterotic groups. However, the genetic diversity in adapted oilseed rape breeding material is rather limited. Therefore, the use of resynthesized Brassica napus as a distant gene pool was investigated. Hybrids were derived from crosses between 44 resynthesized lines with a diverse genetic background and two male sterile winter oilseed rape tester lines. The hybrids were evaluated together with their parents and check cultivars in 2 years and five locations in Germany. Yield, plant height, seed oil, and protein content were monitored, and genetic distances were estimated with molecular markers (127 polymorphic RFLP fragments). Resynthesized lines varied in yield between 40.9 dt/ha and 21.5 dt/ha, or between 85.1 and 44.6% of check cultivar yields. Relative to check cultivars, hybrids varied from 91.6 to 116.6% in yield and from 94.5 to 103.3% in seed oil content. Mid-parent heterosis varied from −3.5 to 47.2% for yield. The genetic distance of parental lines was not significantly correlated with heterosis or hybrid yield. Although resynthesized lines do not meet the elite rapeseed standards, they are a valuable source for hybrid breeding due to their large distance from present breeding material and their high heterosis when combined with European winter oilseed rape

Optimierungsansätze zur Verbesserung von Nachhaltigkeit, Ressourceneffizienz und Tierwohl in ökologischen und konventionellen Betrieben im Netzwerk Pilotbetriebe

In a network of organic and conventional pilot farms with dairy and/or arable production in Germany (www.pilotbetriebe.de) aspects of sustainability, resource efficiency, animal health and welfare and economic aspects are analysed. This is based on on-farm assessments and on whole farm modelling. In the first interdisciplinary workshops on the project farms results were presented and scenarios were developed in a participatory approach by scientists, consultants and farmers to improve N, P and land use efficiency as well as dairy health and welfare. Typical areas of action to optimize sustainability in these aspects were identified on the farms, e.g., complete accounting of manure N (N balance), enrichment of crop rotations with clover grass and cover crops (humus balance), improving forage quality (productivity, nutritional imbalances), improvement of housing conditions and grazing access (animal health and welfare). Systematic integration and detection of interconnectedness of environmental performance of production, animal welfare, resource efficiency and productivity result in a new quality in development of farm concepts

Limits on diffuse fluxes of high energy extraterrestrial neutrinos with the AMANDA-B10 detector

Data from the AMANDA-B10 detector taken during the austral winter of 1997 have been searched for a diffuse flux of high energy extraterrestrial muon-neutrinos, as predicted from, e.g., the sum of all active galaxies in the universe. This search yielded no excess events above those expected from the background atmospheric neutrinos, leading to upper limits on the extraterrestrial neutrino flux. For an assumed E^-2 spectrum, a 90% classical confidence level upper limit has been placed at a level E^2 Phi(E) = 8.4 x 10^-7 GeV cm^-2 s^-1 sr^-1 (for a predominant neutrino energy range 6-1000 TeV) which is the most restrictive bound placed by any neutrino detector. When specific predicted spectral forms are considered, it is found that some are excluded.Comment: Submitted to Physical Review Letter

Extent and structure of linkage disequilibrium in canola quality winter rapeseed (Brassica napus L.)

Linkage disequilibrium was investigated in canola quality winter rapeseed to analyze (1) the prospects for whole-genome association analyses and (2) the impact of the recent breeding history of rapeseed on linkage disequilibrium. A total of 845 mapped AFLP markers with allele frequencies ≥0.1 were used for the analysis of linkage disequilibrium in a population of 85 canola quality winter rapeseed genotypes. A low overall level of linkage disequilibrium was found with a mean r2 of only 0.027 over all 356,590 possible marker pairs. At a significance threshold of P = 2.8 × 10−7, which was derived by a Bonferroni correction from a global α-level of 0.1, only 0.78% of the marker pairs were in significant linkage disequilibrium. Among physically linked marker pairs, the level of linkage disequilibrium was about five times higher with more than 10% of marker pairs in significant linkage disequilibrium. Linkage disequilibrium decayed rapidly with distance between linked markers with high levels of linkage disequilibrium extending only for about 2 cM. Owing to the rapid decay of linkage disequilibrium with distance association analyses in canola quality rapeseed will have a significantly higher resolution than QTL analyses in segregating populations by interval mapping, but much larger number of markers will be necessary to cover the whole genome. A major impact of the recent breeding history of rapeseed on linkage disequilibrium could not be observed