Mapping of quantitative trait loci regulating nitrogen stress tolerance and leaf rust seedling resistance in two selected populations derived from crosses between exotic and elite barley - [kumulative Dissertation]

Ein Ziel der modernen Pflanzenzüchtungsforschung ist es, vorteilhafte exotische Allele aus Wildgerste in Kulturgerste zu übertragen, da diese mehrere gewünschte Eigenschaften bereitstellt. Die meisten dieser Merkmale (z.B. Ertrag) sind komplex und durch viele Gene bestimmt. Solche Gene werden durch quantitative Merkmalsloci (engl.: quantitative trait loci, QTL) repräsentiert, die molekular kartiert werden. Basierend darauf wurden in der vorliegenden Arbeit QTL für verschiedene Merkmale in Gerste kartiert. Die erste Kartierungspopulation war die Introgressionslinienpopulation 'S42IL' (mit zwei N-Stufen: Stress- und Normalbedingung), die zweite war die prä-NAM-Population 'HEB-5' (genestete Assoziationskartierung). In beiden Populationen wurden QTL detektiert, bei denen die exotischen Allele mit vorteilhaften Merkmalseigenschaften assoziiert waren. Die QTL lagen sowohl in bisher unbekannten als auch in bereits bekannten Genomregionen.One aim of modern plant breeding research is to introduce favorable exotic alleles from wild barley into cultivated barley, as this provides multiple desired characteristics. Most of these traits (e.g. yield) are complex and determined through multiple genes. Such genes are represented through quantitative trait loci (QTL) that are mapped molecularly. Under this theme multiple traits were mapped in barley in the present study. The first mapping population was the introgression line population 'S42IL' (with two N levels: stress and conventional condition), the second one was the pre-NAM population 'HEB-5' (nested association mapping). In both populations QTL were detected where exotic alleles were associated with favorable trait characteristics. The QTL lay in so far unknown as well as in already known genomic regions.vorgelegt von Schnaithmann, Floria

Genome-wide association analysis of grain yield-associated traits in a pan-European barley cultivar collection

A collection of 379 Hordeum vulgare cultivars, comprising all combinations of spring and winter growth habits with two and six row ear type, was screened by genome wide association analysis to discover alleles controlling traits related to grain yield. Genotypes were obtained at 6,810 segregating gene-based single nucleotide polymorphism (SNP) loci and corresponding field trial data were obtained for eight traits related to grain yield at four European sites in three countries over two growth years. The combined data were analyzed and statistically significant associations between the traits and regions of the barley genomes were obtained. Combining this information with the high resolution gene map for barley allowed the identification of candidate genes underlying all scored traits and superposition of this information with the known genomics of grain trait genes in rice resulted in the assignation of 13 putative barley genes controlling grain traits in European cultivated barley. Several of these genes are associated with grain traits in both winter and spring barley

Contrasting genetic regulation of plant development in wild barley grown in two European environments revealed by nested association mapping

Barley is cultivated more widely than the other major world crops because it adapts well to environmental constraints, such as drought, heat, and day length. To better understand the genetic control of local adaptation in barley, we studied development in the nested association mapping population HEB-25, derived from crossing 25 wild barley accessions with the cultivar 'Barke'. HEB-25 was cultivated in replicated field trials in Dundee (Scotland) and Halle (Germany), differing in regard to day length, precipitation, and temperature. Applying a genome-wide association study, we located 60 and 66 quantitative trait locus (QTL) regions regulating eight plant development traits in Dundee and Halle, respectively. A number of QTLs could be explained by known major genes such as PHOTOPERIOD 1 (Ppd-H1) and FLOWERING LOCUS T (HvFT-1) that regulate plant development. In addition, we observed that developmental traits in HEB-25 were partly controlled via genotype × environment and genotype × donor interactions, defined as location-specific and family-specific QTL effects. Our findings indicate that QTL alleles are available in the wild barley gene pool that show contrasting effects on plant development, which may be deployed to improve adaptation of cultivated barley to future environmental changes.</p

The Lantern Vol. 76, No. 1, Fall 2008

• Cruel • A Night in Three Parts • The Moment I Said It • To Know • I Will Never Skipskipskip a Rock • The Ravine • Untitled • Skeleton • Midnight Letter • Where Children Come From • Orphan of War • Ciega / Mezquita • The Other Side • Those Dancing Days are Gone • Cycling • The 2nd of July • The Tantric Semantics of Studying Abroad • A Three-Part Study in Musical Relations • Amway Man • Hard Luck Investigator • Spring • Interview With Poet Eleanor Wilnerhttps://digitalcommons.ursinus.edu/lantern/1173/thumbnail.jp

The Lantern Vol. 75, No. 1, Fall 2007

• Black Cat • Divorce • The Picture in the Basement • An Ode to the \u2750s Housewife; or Go Go Sylvia Plath • Paradise from a Clock • The Fifth • Moveable Feast • Deathbed • July 17th • Words • Autobiography • The Raving • The Dream Hater • The Moon Rose Late • Tree, the Big, Very Old One in the Middle of Campus • Apple Bit • Sub Atomic Romance • God Came • Extinction • Ski Masks and Knee Caps • Of Silhouettes and Dominoeshttps://digitalcommons.ursinus.edu/lantern/1171/thumbnail.jp

New loci and candidate genes in spring two-rowed barley detected through meta-analysis of a field trial European network

This study contributes new knowledge on quantitative trait loci (QTLs) and candidate genes for adaptive traits and yield in two-rowed spring barley. A meta-analysis of a network of field trials, varying in latitude and sowing date, with 151 cultivars across several European countries, increased QTL detection power compared to single-trial analyses. The traits analysed were heading date (HD), plant height (PH), thousand-grain weight (TGW), and grain yield (GY). Breaking down the analysis by the main genotype-by-environment trends revealed QTLs and candidate genes specific to conditions like sowing date and latitude. A historical look on the evolution of QTL frequencies revealed that early selection focused on PH and TGW, likely due to their high heritability. GY selection occurred later, facilitated by reduced variance in other traits. The study observed that favourable alleles for plant height were often fixed before those for grain yield and TGW. Some regions showed linkage in repulsion, suggesting targets for future breeding. Several candidate genes were identified, including known genes and new candidates based on orthology with rice. Remarkably, the deficiens allele of gene Vrs1, appears associated to higher GY. These findings provide valuable insights for barley breeders aiming to improve yield, and other agronomic traits

New loci and candidate genes in spring two-rowed barley detected through meta-analysis of a field trial European network

Key message: A dense genome-wide meta-analysis provides new QTLs, reveals breeding history trends and identifies new candidate genes for yield, plant height, grain weight, and heading time of spring barley. Abstract: This study contributes new knowledge on quantitative trait loci (QTLs) and candidate genes for adaptive traits and yield in two-rowed spring barley. A meta-analysis of a network of field trials, varying in latitude and sowing date, with 151 cultivars across several European countries, increased QTL detection power compared to single-trial analyses. The traits analysed were heading date (HD), plant height (PH), thousand-grain weight (TGW), and grain yield (GY). Breaking down the analysis by the main genotype-by-environment trends revealed QTLs and candidate genes specific to conditions like sowing date and latitude. A historical look on the evolution of QTL frequencies revealed that early selection focused on PH and TGW, likely due to their high heritability. GY selection occurred later, facilitated by reduced variance in other traits. The study observed that favourable alleles for plant height were often fixed before those for grain yield and TGW. Some regions showed linkage in repulsion, suggesting targets for future breeding. Several candidate genes were identified, including known genes and new candidates based on orthology with rice. Remarkably, the deficiens allele of gene Vrs1 appears associated with higher GY. These findings provide valuable insights for barley breeders aiming to improve yield and other agronomic traits.</p

Identification of quantitative trait loci for leaf-related traits in an IBM Syn10 DH maize population across three environments

Leaf-related traits (leaf length, leaf width, leaf area and leaf angle) are very important for the yield of maize (Zea mays L) due to their influence on plant type. Therefore, it is necessary to identify quantitative trait loci (QTLs) for leaf-related traits. In this report, 221 doubled haploid lines (DHLs) of an IBM Syn10 DH population were provided for QTL mapping. In total, 54 QTLs were detected for leaf-related traits in single environments using a high-density genetic linkage map. Among them, only eight common QTLs were identified across two or three environments, and the common QTLs for the four traits explained 4.38%-19.99% of the phenotypic variation. qLL-2-1 (bin 2.09), qLW-2-2 (bin 2.09), qLW-6-3(bin 6.07) and qLA-5-2 (bin 2.09) were detected in previous studies, and qLL-1-1, qLAr-1-1, qLAr-2-1 and qLA-7-1 may be new QTLs. Notably, qLW-6-3 and qLA-5-2 were found to be major QTLs explaining 19.99% and 10.96% of the phenotypic variation, respectively. Interestingly, we found three pairs of QTLs (qLW-2-2 and qLAr-2-1, qLW-8-1 and qLL-8-2, qLL-3-3 and qLAr-3-3) that control different traits and that were located on the same chromosome or in a nearby location. Moreover, nine pairs of loci with epistatic effects were identified for the four traits. These results may provide the foundation for QTL fine-mapping and for an understanding of the genetic basis of variation in leaf-related traits