Marker-assisted breeding for Downy mildew, Powderey mildew and Phylloxera resistance at FEM

Il programma di miglioramento genetico per le resistenze a stress biotici ha avuto inizio presso la Fondazione Edmund Mach (FEM) nel 2010. Inizialmente è stata condotta una caratterizzazione sia genotipica che fenotipica di materiali acquisiti da altri programmi di breeding e di materiale selvatico raccolto in New Jersey. Sia i genotipi conosciuti nei database internazionali che i genotipi sconosciuti, imparentati e non, sono stati impiegati come linee parentali nel processo di introgressione e di piramidazione di loci di interesse. Una volta pianificati e ottenuti gli incroci, la valutazione delle progenie è avvenuta seguendo un processo di Marker-Assisted Selection: dapprima è avvenuta la selezione fenotipica in serra in base al tipo di malattia e al numero di loci attesi per la medesima malattia; successivamente si è proceduto con lo screening molecolare in base ai loci specifici attesi nei parentali. Cinque sono i loci Run/Ren associati alla resistenza all'oidio presenti nel programma FEM; riguardo ai loci associati alla resistenza alla peronospora, quattro Rpv sono ben rappresentati nel piano di incroci. Ad oggi il 26% delle F1 è piramidizzato per quattro loci di resistenza

Studi sui tratti di qualità negativa nelle nuove viti mediamente resistenti alle malattie fungine

The varieties of vines tolerant to the main fungal diseases are the object of growing interest because they require fewer treatments for the production of quality grapes. These varieties are considered qualitatively unsuitable especially for some characteristics such as the foxy aroma, the level of anthocyanin diglucosides and the level of methyl alcohol in wines. In the three-year period 2016-2018, from a population of 74 medium resistant varieties placed in a single collection, in Marlengo (BZ), young leaves were taken for DNA analysis; annually 2 surveys of the OIV 452 453, 455 and 456 descriptors were carried out, and, at 18° Brix, sombunches were collected for the analysis of different metabolites. Nano-vinifications were carried out for 32 genotypes. Genotypes with different levels of stacked loci associated with resistance to downy and powdery mildew were detected, with different resistance behaviors over the years. Only some genotypes have aromas of foxy and only 20% of the genotypes analyzed have levels of anthocyanin diglucosides higher than the levels required by current legislation. Some vinifications showed methanol levels higher than the legal limit set. High percentages of genotypes respected the legal levels of metabolites required by current regulations and only genotypes with the presence of V. labrusca showed the aroma of foxy

Fine mapping of the major Fusarium head blight resistance QTL Fhb1 in wheat : identification of near-isogenic lines with recombinations in the QTL region

Weizen ist eine der wichtigsten Kulturpflanzen. Jedoch ist die Ertragsfähigkeit häufig limitiert durch das Auftreten von Schadorganismen. Die Ährenfusariose, vor allem hervorgerufen durch Fusarium graminearum, ist eine der verheerendsten Krankheiten von Weizen und anderen Kulturpflanzen. Neben negativen Effekten auf Ertrag und Saatgutqualität, stellt die Produktion von Mykotoxinen eine Gefahr dar für die Gesundheit von Tier und Mensch. Deshalb ist die Entwicklung von resistenten Sorten ein erklärtes Ziel von Züchtern und Pflanzenwissenschaftlern. Die genetischen Resistenzmechanismen sind bis dato unbekannt, trotz vieler Studien und intensiven Züchtungsstrategien gegen die Ährenfusariose. Viele Quantitative Trait Loci (QTL) wurden identifiziert, welche mit der Resistenz assoziiert sind, aber kein verantwortliches Gen wurde bis jetzt kloniert. Ein QTL, nämlich Fhb1 auf Chromosom 3B, wurde als vielversprechend befunden und für markergestützte Selektion verwendet. Das Ziel dieser Masterarbeit war die Selektion von nah-isogenen Linien (NILs) mit Rekombinationen in der Fhb1 QTL-Region für die Feinkartierung und um die Genklonierung zu unterstützen. Zunächst wurden 2080 NILs in der F2 Generation für die Fhb1-Region untersucht mit zwei flankierenden molekularen Markern (XGWM493 und XBARC133). Dadurch wurden 121 Linien mit Rekombinationen zwischen diesen Markern identifiziert, die meisten davon waren heterozygot für einen von diesen Markern. In einem zweiten Selektionsprozess in der F3 Generation wurden 85 NILs identifiziert, welche homozygot und rekombinant in der Fhb1-Region sind. Die vermeintliche Fhb1-Region der rekombinanten Linien wurde weiter charakterisiert mit Hilfe von zwei weiteren Markern, UMN10 und Snp3BS-8, durch welche sich fünf verschiedene Haplotypen erkennen ließen. Diese Linien stellen eine wichtige genetische Ressource für ein weiteres Feinkartieren dar, um die QTL-Region detailiert zu beschreiben und das Klonieren von Resistenzgenen zu ermöglichen.Wheat is one of the most important crops. However, the productivity is often limited by the occurrence of pest organisms. Fusarium head blight (FHB), which is mainly caused by Fusarium graminearum, is one of the most devastating diseases affecting wheat and other gramineous crop species. Besides negative effects concerning yield and seed quality, the production of mycotoxins poses a hazard to human and animal health. Therefore, the development of resistant cultivars is a declared goal for many breeders and plant scientists. The genetic resistance mechanisms are still largely unknown, despite various studies and intensive breeding strategies against FHB. Numerous quantitative trait loci (QTL) have been identified to be associated with the resistance trait, but none of the underlying genes has been cloned yet. One major QTL, namely Fhb1 on chromosome 3B, was found to be most promising and has thus been used for marker-assisted breeding. The aim of the master thesis at hand was the selection of near-isogenic lines (NILs) with recombinations in the Fhb1 region for the fine mapping of the QTL and finally to support gene cloning. Initially, 2080 NILs in the F2 generation for the Fhb1 region were screened using two molecular markers (XGWM493 and XBARC133) flanking the Fhb1 QTL. Thus, 121 lines with recombinations between the two markers were identified with most of the lines heterozygous for one of the markers. In a second selection step in the F3 generation, 85 NILs were identified to be homozygous and recombinant in the Fhb1 region. The putative Fhb1 region of the recombinant lines was further characterized using two additional markers, UMN10 and Snp3BS-8, allowing the separation of the lines in five haplotypes. These lines serve as an essential genetic resource for subsequent fine mapping, in order to narrow down this large QTL region and to facilitate cloning of the Fhb1 resistance gene(s).submitted by Verena GratlZsfassung in dt. SpracheWien, Univ. für Bodenkultur, Masterarb., 2015(VLID)108348