Dissertation > Excellent graduate degree dissertation topics show

Genetic Map Construction and QTL Mapping for Important Agronomic Traits in Synthetic Hexaploid Wheat

Author: YuMa
Tutor: ZhengYouLiang
School: Sichuan Agricultural University
Course: Crop Genetics and Breeding
Keywords: wheat synthetic wheat genetic map QTL
CLC: S512.1
Type: PhD thesis
Year: 2013
Downloads: 92
Quote: 0
Read: Download Dissertation

Abstract


Most traits in wheat such as growling period, plant height, quality, phosynthesis associated traits, biotic stress and abiotic stress tolerance are generally controlled by multiple genes. Accurate phenotyping and genetic mapping are essential for marker-assisted selection and map-based cloning. And genetic maps are powerful tools for identification of such quantitative trait loci. Genetic variation in Common wheat is poorly, but highly in wild ancestral species of wheat. Therefore, utilization of genetic resources in wild ancestral species of wheat can break the bottleneck of yield breeding in common wheat. Synthetic hexaploid wheats offer breeder ready access to potentially novel genetic variations in wild ancestral species. In present study, we constructed genetic map for recombinant intercross lines (RILs) population derived from the cross of synthetic wheat, and performed QTL mapping for important agronomic traits, to identified novel genetic regions associated investigated traits in synthetic wheat. The major study and result were described as follows:1) Genetic map construction was conducted in a SC (SHW-L1×Chuanmai32) population which contains171lines derived from the cross of synthetic wheat SHW-L1. A total of1,862makers were assigned to21chromosomes and covered a total of3,766.9cM of genetic distance with an average of2.0cM between markers in map constriction. This map is essential to identify novel loci associated agronomic traits in SHW-L1. In addition, we also performed genotyping for SHW-L1, and its parents of AS60and AS2255through the markers located on the map. The genotypic analysis identified129loci were eliminated in SHW-L1, and these loci clustered in32genetic regions. It was suggested that D genomes of SHW-L1suffered more shake than AB genomes in allopolyploidization. These eliminated regions identification will help domestication research and genomic evolution research in wheat.2) QTL mapping for emergence date, tillering date, heading date, flowering date, maturation period, and growling period were performed through the high resolution map of SC population. We also conducted conditional QTL analysis for growling period and other investigated traits to determine the genetic relationships between growling period and its components. A total of30QTLs were identified in present study, which explained3.3-34.7%of the phenotypic variation,10of which explained the phenotypic variation higher than10%, and4of which were environments independent. Conditional analysis suggested that growling period were major effected by heading date, especially the major locus for heading date on2D, which also showed major effect on emergence date and maturation period. In addition, the effect of maturation period on growling period was lower. No significant effect of emergence date and tilling date on growling period were observed, and the effect or flowering date was not sure. This QTL mapping study and genetic relationship analysis between growling period and its components traits should be great practical value and theoretical value for wheat growling period breeding.3) QTL mapping for yield related traits were performed through the high resolution map of SC population. A total of30QTLs were detected in present study, which explained3.87-31.85%of the phenotypic variation,11of which explained the phenotypic variation higher than10%, and21of which were environments independently. For these QTLs,15alleles from synthetic wheat SHW-L1contributed positively to phenotypic variation, especially QTLs on1A,2D (wPt-730529-wPt-8134),4D (wPt-732586-wPt-73040),and6A(wPt-2216-rPt-6189), these environments independent QTLs should be great value for yield breeding in wheat.4) QTL mapping for uppermost internode length, spike length, and plant height were performed in ITMI (W7984×Opata85) and SC populations. We also conducted conditional QTL mapping for plant height and other two investigated traits. A total of40QTLs were identified in ITMI population, which explained2.5-33.3%of the phenotypic variation,15of which explained the phenotypic variation higher than10%, and7of which were detected in all investigated environments. A total of40QTLs were identified in ITMI population, which explained3.4-44.8%of the phenotypic variation,11of which explained the phenotypic variation higher than10%, and6of which were environments independently. Conditional QTL analysis suggests that:Most QTLs identified for UTL and SL were independent to PH, and PH were more independent to SL. The QTL identification and genetic relationship analysis will accelerate selection of suitable locus to improve the commercial wheat morphology to avoid the change of PH.5) QTL mapping for waterlogging tolerance was performed at seedling stage in ITMI population (W7984×Opata85) and SC population. The waterlogging tolerance waterlogging tolerance traits include total dry weight index (TDWI), shoot dry weight index (SDWI), and root dry weight index (RDWI). We also conducted conditional QTL analysis for total dry weight index with other two traits. A total of18QTLs were identified in ITMI population, which explained4.2-18%of the phenotypic variation,13of which explained the phenotypic variation higher than10%. For these QTLs,9alleles from synthetic wheat W7984contributed positively to phenotypic variation. A total of7QTLs were identified in ITMI population, which explained5.9-13.2%of the phenotypic variation,4of which explained the phenotypic variation higher than10%. For these QTLs,2alleles from synthetic wheat W7984contributed positively to phenotypic variation. These results indicated that SDWI showed tighter genetic correlation with TDWI than RDWI in both ITMI population and SC population. Several QTLs for RDWI were coordinated with SDWI to affect the expression of QTL for TDWI, and most of them showed suppression. Breakthrough these suppressed relationship will be notable improvement for waterlogging breeding in wheat.

Related Dissertations

  1. Genetic Model Analysis and QTL Mapping of Agronomic and Quality Traits in Soybean,S565.1
  2. Functional Analysis of Proteins Encoded by RNA2 of Wheat Yellow Mosaic Virus,S435.121
  3. Pathogenic Differentiation and Genetic Diversity of Wheat Sharp Eyespot in Henan Province,S435.121
  4. The Identificationand Rapdanalysis of Wheat Root Lesion Pathogens in Henan Province,S435.121
  5. Nitrogen Regulation and Management on High-yield Wheat-maize Rotation System,S512.1
  6. Genetic Analysis and Molecular Mapping of QTL for Rice Black-Streaked Dwarf Disease Resistance in Rice,S511
  7. Effect of Nitrogenapplication Patterns on Variation of Soil Nitrate-N and Grain Yield of Wheat and Maize,S512.11
  8. Genetic Segregation Analysis and QTL Mapping as Well as Association Analysis for Panicle Angle Trait in Japonica Rice (Oryza Sativa L.),S511.22
  9. Study on Nitrogen Accumulation Characteristics of Winter Wheat with Yield of 10t/ha, Diagnosis and Nitrogen Application Technologies,S512.1
  10. Optimization of Fermentation Conditions of Recombinant Lipoxygenase for the Production in Wheat Flour,TS201.25
  11. Study on Extraction,purification and Antioxidant Activity of Wheat Germ Polysaccharides,TS210.1
  12. Characterization of Mineral Phosphate-Solubilizing Bacterium K3 and Colonization under Different Soil,S144.9
  13. Design and Implementation of the Growing Visualization System for Wheat Population,S512.1
  14. New Methodology for Mapping Resistance Trait Loci in Crop Cultivar Population,S336
  15. Trajectory Analysis of Wheat Aphids During Long-distance Migration Using HYSPLIT Model,S433
  16. Genetic Structure of the Wheat Powdery Mildew Populations from Henan, Hubei and Chongqing Province (City),S435.121
  17. Cloning 1Dx5 Gene from the Xinjiang Wheat Variety and Constructing Its Expression Vector,S512.1
  18. Studies on Regulating Effect of Nitrogen Rates on Starch Granule Distribution in Grain of Wheat,S512.1
  19. Accumulation of High Molecular Weight Glutenin Subunits in Wheat Grain as Regulated by Nitrogen Rate,S512.1
  20. Effects of Pre-Anthesis Drought Hardening on Grain Yield and Quality Formation in Wheat under Post-Anthesis Drought and Its Physiological Mechanism,S512.1
  21. Difference in Development between Culm and Tiller Roots and Their Contribution to Grain Yield and Quality in Wheat (Triticum Aestivum L.),S512.1

CLC: > Agricultural Sciences > Crop > Cereal crops > Wheat > Wheat
© 2012 www.DissertationTopic.Net  Mobile