Comprehensive Study Notes for ECCB 310 Exam

Hemlock Dwarf Mistletoe Impact

  • Hemlock dwarf mistletoe (Arceuthobium tsugense) affects 21% of western and mountain hemlocks in the Pacific Northwest.
  • Severe infestations lead to:
    • Growth loss
    • Reduced wood quality
    • Tree mortality
  • Variability in genetic resistance exists.

Tree Improvement Program Steps for Coastal British Columbia

  1. Assessment of Plus Trees

    • Methodology: Employ Plus tree selection for identifying resistant trees.
    • Rationale: It focuses on phenotypic characteristics but relies on subjective and baseline comparisons.
    • Selection Process: Testing for resistance through graft inoculation reduces selected plus trees to 50 due to susceptibility.

  2. Establishment of Breeding Orchard

    • Identify optimal sites for breeding orchards based on environmental factors and genetic diversity.
    • Considerations include:
      • Soil type
      • Local climate
      • Genetic backgrounds of the trees.

  3. Mating Design Selection

    • Choose appropriate mating designs (i.e., factorial, complementary) based on breeding goals.
    • Evaluate advantages:
      • Increases genetic diversity.
      • Allows for targeted trait enhancement.
    • Disadvantages include complexity in management.

  4. Progeny Testing Layout

    • Design Considerations:
      • Number of test locations and blocks
      • Plot types (rectangular, single-tree, etc.)
      • Potential special tests for specific traits.
    • Evaluate reasons for chosen layout to ensure validity and assessment accuracy.

  5. Development of Seed Orchard

    • Formulate plans for seed orchards focusing on:
      • Genetic diversity
      • Maintenance procedures
      • Design for optimal seed production.
    • Future Planning: Set long-term goals for seed yield and genetic improvements over generations.

Genetic Engineering of Trees

Components for Genetic Engineering
  • Requirements include:
    • A) Genes to insert
    • B) Regulatory elements
    • C) Methods to introduce genes
    • D) Plant regeneration methods.
Selectable Markers Examples
  • A) GUS
  • B) neomycin phosphotransferase II (nptII)
  • C) Phosphinothricin acetyl transferase (bar)
  • D) Green fluorescent protein.
Transformation Methods
  • Methods comprising:
    • A) Agrobacterium-mediated transformation
    • B) Microprojectile bombardment
    • C) Polymerase chain reaction (PCR)
    • D) Southern blot hybridization.
Characteristics of Agrobacterium tumefaciens
  • Affects plant DNA and can result in tumor formation; inserts functional genes into the plant genome.
Microprojectile Bombardment Details
  • Involves using gold particles to shoot DNA into cells, allowing stable transformations.
Achieving Roundup Resistance
  • Strategies include:
    • A) Using mammalian EPSPS genes
    • B) Inserting Agrobacterium EPSPS genes
    • C) Introducing GOX gene
    • D) Using genes from Bacillus thuringiensis.
Bacterial Gene Adjustment in Plants
  • Common adaptations involve:
    • A) Bacterial promoters for expression
    • B) Codon usage changes for plant compatibility.
Bacillus thuringiensis Gene Traits
  • Produce protoxin forms which are toxic to specific insect species without harming mammals.

Seed and Nursery Management

Significance of Seed Harvest Timing
  • Factors to consider:
    • A) Immature seeds decrease germination chances
    • B) Mature seeds are vulnerable to predation
    • C) Recovery difficulties once seeds are shed.
Measurement of Seed Maturity
  • Methods include:
    • A) Monitoring transitions in seed color
    • B) Floating conifer cones in liquids for viability testing.
Seed Stratification Essentials
  • Best practices include:
    • C) Cold storage of dry seeds
    • D) Involves initial soaking in water before storage.
Seedling Advantages
Bare root seedlings
  • Advantages:
    • A) Lower production costs
    • B) More effective shipping logistics.
Container grown seedlings
  • Advantages:
    • B) Functionality on poor soils
    • C) Flexibility regarding planting times.
Molecular Markers in Tree Improvement
Desired Characteristics
  • Good characteristics include:
    • A) Widespread genome distribution
    • D) Co-dominant traits.
Progeny Tests Utility
  • Utility in genetic evaluation and rogueing existing seed orchards by analyzing performance data.
Seed Production Areas (SPA)
  • Nature of SPAs involves:
    • A) Management of tree phenotypes for improved protential.
    • D) Application in tree improvement programs, particularly in southeastern U.S.
Final Notes on Seed Collection and Genetic Gain
  • Directed collections aim to exploit genetic gains effectively whilst ensuring high selection intensity.
Breeding and Selection Metrics
  • Example Calculation:
    • Expected Gain: Calculated from the mean comparison between selected populations and base populations for trait enhancement.