Genetic Mapping of the Common and Dwarf Bunt Resistance Gene Bt12 Descending From the Wheat Landrace PI119333

Common bunt (CB), caused by Tilletia caries and T. foetida, and dwarf bunt (DB), caused by T. controversa, are particularly destructive diseases of wheat grown under organic (low-input) production conditions and negatively affect both grain yield and quality. A total of 16 race specific bunt resistance genes have been proposed to date. Thereof, only Bt9 and Bt10 have been mapped so far. A mapping and two validation populations comprising 176 recombinant inbred lines were evaluated for CB and DB in artificially inoculated field trials. The mapping population was derived from the cross of the Bt12 carrier PI119333 and the susceptible cultivar ‘Rainer’. The population was genotyped with the Illumina 15 K SNP chip and the major QTL QBt.ifa-7DS representing Bt12 was identified on chromosome 7DS, explaining 39% and 14% of the phenotypic variation for CB and DB resistance, respectively. Selected SNP markers were turned into Kompetitive Allele-Specific (KASP) markers and used to validate Bt12 in two independent validation populations. These markers can be used for introgressing Bt12 into regionally adapted elite breeding material

Breeding for organic agriculture: evaluation of common bunt resistance in three winter wheat populations derived from M822123, PI178383 and PI560841-bcl

Weizensteinbrand (Tilletia caries, T. laevis) zählt weltweit zu den bedeutendsten Weizenkrankheiten. Genetische Resistenz ist der vielversprechendste Ansatz zur Kontrolle von Weizensteinbrand in der ökologischen Landwirtschaft. Zurzeit sind die meisten europäischen Winterweizensorten anfällig, allerdings wurde Steinbrandresistenz in exotischem Material wie türkischen Landrassen gefunden. Drei Winterweizenpopulationen aus Kreuzungen zwischen drei exotischen, steinbrandresistenten Eltern (M822123, PI178383, PI560841-bcl) und zwei österreichischen Sorten (Rainer, Midas) mit jeweils 100 bis 130 Genotypen wurden 2015 nach künstlicher Inokulation des Saatguts auf Resistenz gegen Weizensteinsteinbrand in einem Feldversuch geprüft. Zusätzlich wurden 20 Sorten, die zurzeit in Österreich für die Produktion von Biowinterweizen verwendet werden, sowie 57 Bio-Zuchtstämme auf Weizensteinbrandresistenz getestet. Ziel der Studie war, die Kartierungspopulationen hinsichtlich ihres Resistenztyps, Anzahl an Resistenzgenen und Verwendungsmöglichkeiten zu charakterisieren. 75% der Genotypen, die von M822123 beziehungsweise PI178383 abstammen, wurden als resistent klassifiziert und nur 17.65% von PI560841-bcl. Diese Ergebnisse weisen darauf hin, dass die Resistenz von M822123 und PI178383 auf zwei voneinander unabhängig segregierenden Resistenzgenen basiert. Die Resistenz von PI560841-bcl ist quantitativ und basiert auf zahlreichen Resistenzgenen. Die Resistenzgene von M822123 und PI178383 sind in Österreich wirksam und Genotypen beider Kartierungspopulationen sind sehr interessant für Züchtungsprogramme. Eine Genotypisierung dieser Kartierungspopulationen wird empfohlen, um die Resistenzgene zu kartieren und molekulare Marker für die Verwendung in ökologischen Weizenzüchtungsprogrammen zu entwickeln. Alle untersuchten Sorten waren hoch anfällig. Resistentes Züchtungsmaterial konnte identifiziert werde und zeigt die erfolgreiche Einkreuzung von Resistenzgenen in angepasstes Material.Common bunt (Tilletia caries, T. laevis) is one of the most destructive wheat diseases worldwide. Host resistance is the most promising approach to control common bunt in organic agriculture. Currently, most European winter wheat cultivars are susceptible, but bunt resistance was identified in exotic material, such as Turkish landraces. Three winter wheat mapping populations derived from biparental crosses between three exotic sources of bunt resistance (M822123, PI178383, PI560841-bcl) and two susceptible Austrian cultivars (Rainer, Midas) each consisting of 100 to 130 genotypes were screened for common bunt resistance in an artificially seed-inoculated field trial in 2015. Furthermore, 20 cultivars currently used in organic winter wheat production in Austria and 57 organic breeding lines were tested for common bunt resistance. The aim of this study was to evaluate the mapping populations with regard to their type of resistance, number of resistance genes and possible applications. 75% of the genotypes derived from M822123 and PI178383 were classified as resistant and only 17.65% from PI560841-bcl. Results therefore suggest that resistance of M822123 and PI178383 is mediated by two independently segregating major resistance genes. Resistance of PI560841-bcl is of quantitative nature with several minor genes involved. The resistance genes of M822123 and PI178383 are effective in Austria and genotypes of both mapping populations are extremely interesting for practical breeding programs. Genotyping of these mapping populations is recommended in order to map resistance genes and develop molecular markers for the application in resistance breeding programs. All tested cultivars were found to be highly susceptible. Resistant breeding lines could be identified and demonstrate the successful introgression of resistance genes into adapted lines.submitted by Julia Friederike HagenguthZusammenfassung in deutscher SpracheUniversität für Bodenkultur Wien, Masterarbeit, 2016(VLID)193548

Cultivation Systems, Light Intensity, and Their Influence on Yield and Fruit Quality Parameters of Tomatoes

The yield and fruit quality parameters of tomatoes are influenced by environmental conditions, and cultivation systems play an important role in improving quality, apart from breeding. We examined five breeding lines and one cultivar in five cultivation systems for yield and fruit quality parameters. The cultivation systems include a single-glazed greenhouse with and without supplementary LED interlighting; a double-glazed greenhouse with and without supplementary LED interlighting; and an organic cultivation system on the field with a rainout shelter. Plants and fruits grown in the double glazing system showed significantly lower values for plant height, yield, DM, TSS, fructose, glucose, antioxidant capacity (DPPH, TEAC), TPC, calcium, phosphorus, and manganese content than in the single-glazed greenhouse, which can be explained by the lower light transmittance. However, it could be seen that the additional LED interlighting could lower the negative effect on yield and quality traits due to double glazing