Resistenzzüchtung für den Ökologischen Landbau bei Getreide

Fazit Auch im Ökologischen Landbau gibt es Forschungsbedarf für Resistenzzüchtung, die Schwerpunkte sind aber teilweise andere als im konventionellen Bereich. Bei Ährenfusariosen kann der Ökologische Landbau die vielfältigen Bestrebungen der konventionellen Züchter nutzen, in dem er die Resistenz bei der Sortenwahl berücksichtigt. Bereits mittelanfällige Sorten könnten hier einen ausreichenden Schutz bieten. Bei Mutterkorn ist dringender Handlungsbedarf bei Roggen geboten, da hier mit Kulturmaßnahmen wenig Fortschritte zu erzielen sind. Die genetischen Unterschiede lassen gute Selektionsmöglichkeiten erwarten. Bei Triticale scheint aufgrund der bisherigen Ergebnisse wegen des geringen Befalls keine Züchtung erforderlich zu sein. Anders sieht es bei den Brandkrankheiten des Weizens aus. Wenn die Saatgutproduktion ganz oder teilweise unter ökologischen Bedingungen stattfinden soll, kann es zunehmend zu Problemen kommen, brandfreies Z-Saatgut zu produzieren. Dies zeigen die Erfahrungen aus Osteuropa, wo aus wirtschaftlichen Gründen kaum noch gebeizt wird und die Brandpilze als Schadursache rasch wieder oberste Priorität erlangt haben

Biometrical analysis of alternative plot types for selection in rye

Maximizing the efficiency of selection for yield and baking quality of winter rye (Secale cereale) requires reliable knowledge of the pertinent population parameters. Estimates of variances, heritabilities and genetic correlations from (1) large (~ 5 m²) drilled (LD) plots, (2) micro drilled (MD) plots, and (3) one-row plots of 4 spaced plants (SP) are reported. Thirty-eight single crosses of rye were grown at 2 locations for 2 years in LD, MD and SP plots replicated 2, 4 and 6 times, respectively. Genotypic differences were significant in all plot types for all agronomic and quality traits, although estimates of genetic variances were smaller in LD than MD or SP plots for grain yield, 32-spike weight and grains/spike. Heritabilities on an entry mean basis (0.62 to 0.95) were similar among plot types, but on a single plot basis estimates were lower for SP than for MD or LD plots. Genetic correlations were high between all 3 plot types, with correlations between LD and SP plots being approximately 1.0 for falling number, 1000-grain weight, and flowering date, 0.90 for grain yield, grains/spike, test weight and height, and 0.70 for tiller number. Based on the high heritabilities achieved in small plots and the close agreement between MD- or SP- with LD-plot performance it was concluded that greater use should be made of small plot types when selecting for yield and quality in winter ry

Verminderung gefährlicher Alkaloide in der Nahrungskette durch die züchterische Verbesserung der Mutterkorn-Resistenz von Roggen

Roggen ist als Fremdbefruchter besonders anfällig für einen Befall mit Mutterkorn, der durch eine Infektion mit dem Schadpilz Claviceps purpurea (Fr.) Tul. hervorgerufen wird. Ziele dieser Studie waren die Suche nach effektiven Resistenzträgern gegen Mutterkorn aus genetischen Ressourcen, die Untersuchung der Vererbung von selbstfertilen Roggenmaterialien sowie die Analyse der Wechselwirkungen von Wirtsgenotyp und Mutterkornpilz hinsichtlich der Zusammensetzung und Toxizität der Alkaloide. Zur Untersuchung der Anfälligkeit, von Wirtspflanzen war es notwendig mit CMS (Cytoplasmatic Male-Sterile) Material zu arbeiten. Über drei Jahre wurden an zwei bzw. drei Standorten 75 selbstfertile CMS-Linien und 126 CMS-Einfachkreuzungen sowie 90 Testkreuzungen mit Genetischen Ressourcen deutscher, polnischer und russischer Herkunft. unter ökologischen Bedingungen angebaut, künstlich inokuliert und auf Mutterkornresistenz geprüft. Die Genetischen Ressourcen zeigten nicht in allen Fällen signifikante genotypische Unterschiede. Vor allem im deutschen geprüften Material war keine Signifikanz nachweisbar. Die Linien hatten geringere Mutterkorngewichte als die CMS-Einfachkreuzungen und zeigten immer signifikante genotypische Varianzen, die Einfachkreuzungen in den meisten Fällen. Die Korrelation zwischen beiden Materialgruppen war nur in den ersten beiden Jahren signifikant (r=0,6-0,7; P=0,01). Der mittlere Gesamtalkaloidgehalt der Linien war bei niedrigeren Mutterkorngewichten um ca. 25 % höher als bei den Einfachkreuzungen. Die genotypischen Varianzen für Alkaloide waren bei allen Experimenten und Materialien nicht oder nur schwach signifikant. Die Alkaloidgehalte erwiesen sich als kaum vom geprüften Roggentyp abhängig; aber zeigten starke umweltbedingte Unterschiede. Die Ergebnisse zeigen dass auch im selbstfertilen Material eine gezielte Resistenzselektion möglich ist. Aufgrund quantitativer Vererbung der Resistenz und hoher Genotyp x Umwelt-Wechselwirkungen ist dies allerdings noch ein langer Weg

Multi-Layer Inkjet Printed Contacts to Si

Ag, Cu, and Ni metallizations were inkjet printed with near vacuum deposition quality. The approach developed can be easily extended to other conductors such as Pt, Pd, Au, etc. Thick highly conducting lines of Ag and Cu demonstrating good adhesion to glass, Si, and printed circuit board (PCB) have been printed at 100-200 deg C in air and N2 respectively. Ag grids were inkjet-printed on Si solar cells and fired through the silicon nitride AR layer at 850 deg C, resulting in 8% cells. Next generation inks, including an ink that etches silicon nitride, have now been developed. Multi-layer inkjet printing of the etching ink followed by Ag ink produced contacts under milder conditions and gave solar cells with efficiencies as high as 12%

Multi-Layer Inkjet Printed Contacts for Silicon Solar Cells: Preprint

Ag, Cu, and Ni metallizations were inkjet printed with near vacuum deposition quality. The approach developed can be easily extended to other conductors such as Pt, Pd, Au, etc. Thick highly conducting lines of Ag and Cu demonstrating good adhesion to glass, Si, and printed circuit board (PCB) have been printed at 100-200 C in air and N2 respectively. Ag grids were inkjet-printed on Si solar cells and fired through the silicon nitride AR layer at 850 C, resulting in 8% cells. Next generation inks, including an ink that etches silicon nitride, have now been developed. Multi-layer inkjet printing of the etching ink followed by Ag ink produced contacts under milder conditions and gave solar cells with efficiencies as high as 12%

Direct-Write Contacts: Metallization and Contact Formation; Preprint

Using direct-write approaches in photovoltaics for metallization and contact formation can significantly reduce the cost per watt of producing photovoltaic devices. Inks have been developed for various materials, such as Ag, Cu, Ni and Al, which can be used to inkjet print metallizations for various kinds of photovoltaic devices. Use of these inks results in metallization with resistivities close to those of bulk materials. By means of inkjet printing a metallization grid can be printed with better resolution, i.e. smaller lines, than screen-printing. Also inks have been developed to deposit transparent conductive oxide films by means of ultrasonic spraying

The identification of QTL controlling ergot sclerotia size in hexaploid wheat implicates a role for the Rht dwarfing alleles

The fungal pathogen Claviceps purpurea infects ovaries of a broad range of temperate grasses and cereals, including hexaploid wheat, causing a disease commonly known as ergot. Sclerotia produced in place of seed carry a cocktail of harmful alkaloid compounds that result in a range of symptoms in humans and animals, causing ergotism. Following a field assessment of C. purpurea infection in winter wheat, two varieties ‘Robigus’ and ‘Solstice’ were selected which consistently produced the largest differential effect on ergot sclerotia weights. They were crossed to produce a doubled haploid mapping population, and a marker map, consisting of 714 genetic loci and a total length of 2895 cM was produced. Four ergot reducing QTL were identified using both sclerotia weight and size as phenotypic parameters; QCp.niab.2A and QCp.niab.4B being detected in the wheat variety ‘Robigus’, and QCp.niab.6A and QCp.niab.4D in the variety ‘Solstice’. The ergot resistance QTL QCp.niab.4B and QCp.niab.4D peaks mapped to the same markers as the known reduced height (Rht) loci on chromosomes 4B and 4D, Rht-B1 and Rht-D1, respectively. In both cases, the reduction in sclerotia weight and size was associated with the semi-dwarfing alleles, Rht-B1b from ‘Robigus’ and Rht-D1b from ‘Solstice’. Two-dimensional, two-QTL scans identified significant additive interactions between QTL QCp.niab.4B and QCp.niab.4D, and between QCp.niab.2A and QCp.niab.4B when looking at sclerotia size, but not between QCp.niab.2A and QCp.niab.4D. The two plant height QTL, QPh.niab.4B and QPh.niab.4D, which mapped to the same locations as QCp.niab.4B and QCp.niab.4D, also displayed significant genetic interactions

DArT markers tightly linked with the Rfc1 gene controlling restoration of male fertility in the CMS-C system in cultivated rye (Secale cereale L.)

The Rfc1 gene controls restoration of male fertility in rye (Secale cereale L.) with sterility-inducing cytoplasm CMS-C. Two populations of recombinant inbred lines (RIL) were used in this study to identify DArT markers located on the 4RL chromosome, in the close vicinity of the Rfc1 gene. In the population developed from the 541×2020LM intercross, numerous markers tightly linked with the restorer gene were identified. This group contained 91 DArT markers and three SCARs additionally analyzed in the study. All these markers were mapped in the distance not exceeding 6 cM from the gene of interest. In the second mapping population (541×Ot1-3 intercross), only 9 DArT markers located closely to the Rfc1 gene were identified. Five of these DArT markers were polymorphic in both populations