Dokument: The genetics and association of photosynthesis parameters and flag leaf morphology in barley and their use for breeding
| Titel: | The genetics and association of photosynthesis parameters and flag leaf morphology in barley and their use for breeding | |||||||
| URL für Lesezeichen: | https://docserv.uni-duesseldorf.de/servlets/DocumentServlet?id=74413 | |||||||
| URN (NBN): | urn:nbn:de:hbz:061-20260914-111434-3 | |||||||
| Kollektion: | Dissertationen | |||||||
| Sprache: | Englisch | |||||||
| Dokumententyp: | Wissenschaftliche Abschlussarbeiten » Dissertation | |||||||
| Medientyp: | Text | |||||||
| Autor: | Gao, Yanrong [Autor] | |||||||
| Dateien: |
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| Beitragende: | Prof. Dr. Stich, Benjamin [Gutachter] PD. Dr. Matsubara, Shizue [Gutachter] | |||||||
| Dewey Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik » 580 Pflanzen (Botanik) | |||||||
| Beschreibung: | Meeting the demands of a growing global population requires substantial increases in crop yield, with optimization of photosynthesis recognized as a key strategy. However, natural genetic variation in photosynthesis and its integration into breeding remain underexplored, constrained by difficulties in high-throughput field phenotyping, strong environmental sensitivity, and complex genetic control. Leaf morphology, particularly flag leaf size, is also a major determinant of photosynthetic capacity and assimilate supply to grains, yet its genetic architecture in barley is not well understood.
This thesis addresses these gaps by combining physiological phenotyping, quantitative genetics, and genomic prediction to assess the potential of incorporating photosynthesis-related parameters into barley breeding for yield. First, we compared gas exchange-based and chlorophyll fluorescence-based techniques and showed that chlorophyll fluorescence reliably detects genetic variation in Photosystem II (PSII) parameters under controlled conditions. In the field, chlorophyll fluorescence of barley inbred lines reflected variation in carbon assimilation observed in climate chambers, confirming its value as a proxy for photosynthetic performance. Strong genotype × environment interactions and developmental stage effects indicated that single time-point measurements are insufficient, underscoring the need for time-series, high-throughput phenotyping to robustly characterize photosynthesis (Chapter 2). Using both a diverse panel of barley inbred lines and a large recombinant inbred line (RIL) population, we found significant, developmentally dynamic correlations between photosynthesis parameters (e.g. Fvʹ/Fmʹ, NPQt) and yield-related traits, highlighting the temporal nature of the photosynthesis–yield relationship (Chapters 2–3). Heritabilities of photosynthesis traits ranged from low to moderate, and dynamic QTL across development revealed a highly polygenic and complex genetic architecture. Genomic prediction outperformed QTL-based approaches, and prediction ability for yield improved when photosynthesis parameters were integrated into genomic prediction models (Chapter 3). In parallel, genetic analysis of flag leaf size in a double round-robin barley population (HvDRR) revealed substantial heritability for flag leaf length and width and identified 24 consensus QTL, including 17 novel loci. Fine mapping of qHvDRR-FLS-8 indicated shared effects on multiple leaves, and cellular analysis showed that variation in epidermal cell number primarily underlies differences in leaf size (Chapter 4). Overall, this thesis demonstrates considerable exploitable variation in photosynthesis-related traits and flag leaf morphology in barley and proposes a framework for integrating these traits into genomic prediction pipelines, offering a promising avenue to support future crop yield improvement and food security. | |||||||
| Lizenz: |  Dieses Werk ist lizenziert unter einer Creative Commons Namensnennung 4.0 International Lizenz | |||||||
| Fachbereich / Einrichtung: | Mathematisch- Naturwissenschaftliche Fakultät » WE Biologie » Genetik | |||||||
| Dokument erstellt am: | 14.09.2026 | |||||||
| Dateien geändert am: | 14.09.2026 | |||||||
| Promotionsantrag am: | 09.12.2025 | |||||||
| Datum der Promotion: | 10.06.2026 |
