Das Projekt "Allele mining in wild barley: finding new exotic genes which control flowering time in the barley nested association mapping (NAM) population HEB-25" wird vom Umweltbundesamt gefördert und von Universität Halle-Wittenberg, Institut für Agrar- und Ernährungswissenschaften, Professur für Pflanzenzüchtung durchgeführt. During the first phase of the priority program SPP1530, we have developed HEB-25 (Halle exotic barley), the first barley nested association mapping (NAM) population world-wide (Schnaithmann et al. 2014, Maurer et al. submitted). HEB-25 is ideally suited to study, both, biodiversity present in wild barley and to serve as a source of exotic alleles for barley breeding. So far, HEB-25 was genetically characterized with a 9k Infinium iSELECT chip and used to map novel as well as previously known QTLs/genes with high precision, which regulate FTi and other agronomic traits. By the start of the second SPP phase, the Pillen lab will have access to exome capture data of HEB-25, which will allow to align the allelic sequences of the 26 HEB parents for more than 20,000 high confidence barley gene models and to study their inheritance in HEB lines. The exome capture sequence data is also useful to define exotic haplotypes and to study their gene function in HEB-25 with a, so far, unmatched genetic resolution in genome-wide association studies (GWAS). During the second phase of the SPP, we aim to dig deeper into the wealth of functional diversity we previously identified in HEB-25. In this regard, we have set up the following three work packages (WP), which are jointly coordinated by Dr. Kumlehn and Prof. Pillen. WP 1: Cloning and characterizing exotic alleles of a novel FTi QTL. In WP 1, a novel HEB-25 QTL on chromosome 4H will be isolated and characterized, where the exotic barley donor alleles cause late flowering phenotypes across and within the 25 HEB families compared to the recipient parent Barke. By cloning newly identified exotic FTi QTL alleles, we will raise the understanding of FTi regulation to improve the genetic architecture of crop plants via knowledge based breeding. WP 2: Allele mining for exotic haplotypes of known FTi genes. In WP 2, barley transformants, stably over-expressing a set of 12 wild barley alleles of known functional FTi genes will be generated, which caused extreme early or late flowering phenotypes in HEB-25. Subsequently, FTi effects and additional pleiotropic effects of the selected transformants will be characterized in greenhouse and field experiments. By transformation of an elite barley genotype with functional wild barley alleles of approved FTi regulating genes, we will study modification of FTi towards crop improvement by altering the expression or function of individual genes either by genetic modification or by mutation. WP 3: HEB-YIELD: A crosstalk between FTi and abiotic stress tolerance in HEB-25. In WP 3, a set of 48 HEB lines will be selected, segregating at four important FTi genes (Ppd-H1, denso, Vrn-H1 and Vrn-H3). (abridged text)
Das Projekt "BARLEY-NAM - Locating exotic genes that control agronomic traits under stress in a wild barley nested association mapping (NAM) population" wird vom Umweltbundesamt gefördert und von Universität Halle-Wittenberg, Institut für Agrar- und Ernährungswissenschaften, Professur für Pflanzenzüchtung durchgeführt. Delivering sustainable food production in the face of climate change requires a revolution in breeding crops that deliver high and sustainable yield under fluctuating disadvantageous environmental conditions. The ancestral wild germplasm of modern crops contains allelic variants that can achieve this goal, yet modern crops are becoming increasingly depleted in biodiversity. The two key obstacles to successful exploitation of wild germplasm are finding the wild-derived alleles needed and testing them in the field. The BARLEY-NAM project will use wild barley (Hordeum vulgare ssp. spontaneum) as a model and apply novel genomic and breeding tools to improve agronomic performance of elite barley under abiotic and biotic stresses. For this, we will apply the nested association mapping (NAM) approach using the first cereal NAM population, HEB-25. HEB-25 comprises 1,420 BC1S3 lines, sub-divided into 25 families, originating from crosses of the elite barley cultivar Barke with 25 different wild barley donors. The HEB-25 lines will first be assessed for allele content at 21,643 genes (every known high-confidence barley gene), employing state-of-the-art exome capture and next generation sequencing. Second, all HEB lines will be cultivated in field trials in Germany, Scotland and Israel to assess agronomic performance under nitrogen deficiency, drought and pathogen attack. Yield components and nutrient content will be scored, as well as resistance against the major barley diseases leaf rust, yellow rust and net blotch. In addition, agronomic performance will be modelled by non-invasive remote sensing technology to establish phenotype predictions. Third, the collected data sets will be archived and further processed in a central data warehouse, built around a custom web-accessible relational database. Fourth, genotype and phenotype data of HEB-25 will be combined in a genome-wide association scan (GWAS) to identify wild barley alleles that improve plant performance under stress. Fifth, to validate the identified trait-improving exotic alleles, segregating high-resolution progeny will be developed from the HEB lines. The BARLEY-NAM project will be beneficial in two directions. On the one hand, the genes and gene variants regulating agronomic traits in barley will be defined at a level of detail unprecedented for the crop and this will inform future strategies for parallel improvement in wheat and rye. On the other hand, trait-improving wild barley alleles will be available for application in future barley breeding. This will lead to new barley cultivars with improved performance and extend the biodiversity and sustainability of the elite barley gene pool.