ECCB 310 Final Exam Review

Dwarf Mistletoe Infestation

  • Hemlock Dwarf Mistletoe (Arceuthobium tsugense)
    • Infests 21% of western and mountain hemlocks in the Pacific Northwest.
    • Severe infestations lead to:
    • Growth loss
    • Reduction in wood quality
    • Tree mortality
    • Genetic resistance varies among trees.

Tree Improvement Program Steps

  • Focus on developing a program in coastal British Columbia to breed for:
    • Resistance to dwarf mistletoe
    • Increased volume in western hemlock.
1. Plus Tree Selection
  • Method Comparison
    • Baseline Method: Involves identifying superior candidates.
    • Subjective Method: Based on visual assessment and expert opinion.
  • Rationale for Selection:
    • Choose based on situations requiring rapid evaluation or subjective recommendations.
  • Testing for Resistance:
    • Test plus trees via inoculation of grafts.
    • Assume this process reduces plus trees to 50; affects selection dynamics.
2. Breeding Orchard Establishment
  • Steps to establish a breeding orchard include:
    • Determine genetic diversity and representativeness of sampled trees.
    • Factors affecting choice:
    • Environmental conditions
    • Pest and disease pressures.
3. Mating Design Selection
  • Identify mating designs to be employed:
    • Examples of Mating Designs:
    • Mass mating
    • Tester mating
    • Diallel mating.
    • Consider advantages (e.g., maximizing genetic gain) and disadvantages (e.g., complexity).
4. Progeny Tests Layout
  • Factors to consider:
    • Number of Locations: For environmental robustness.
    • Number of Blocks: To account for variability.
    • Plot Type: Options include rectangular, row, or single-tree plots.
    • Special tests: To assess specific traits or responses to treatments.
    • Analyze advantages and disadvantages for each plot type.
Seed Orchard Development
  • Development plan for seed orchards:
    • Design focused on minimizing pollen contamination and optimizing production.
    • Evaluate advantages and disadvantages, such as high genetic gain vs. operational complexity.
    • Forward-looking plans for breeding goals.

Genetic Engineering of Trees

  • Requirements for Genetic Engineering:
    • Necessary Components:
    • A) Genes to insert
    • B) Regulatory elements
    • C) Method to insert genes
    • D) Regeneration techniques for whole plants.
Selectable Markers
  • Examples:
    • A) GUS
    • B) nptII (neomycin phosphotransferase II)
    • C) bar (phosphinothricin acetyltransferase)
    • D) green fluorescent protein.
Transformation Methods
  • Methods Used:
    • A) Agrobacterium-mediated transformation
    • D) Microprojectile bombardment.
Agrobacterium Functionality
  • Can:
    • A) Insert any DNA sequence
    • B) Cause crown gall tumors
    • C) Transfer its own DNA.
Microprojectile Bombardment
  • Mechanism:
    • B) Coated gold particles with DNA are shot into the nucleus.
Round-up Resistance Mechanisms
  • Achievable via:
    • B) Using EPSPS genes from Agrobacterium.
    • C) Inserting GOX gene for degradation of round-up.
Genetic Changes Needed for Bacterial Genes
  • Changes Required:
    • A) Use of a bacterial promoter
    • B) Codon usage changes.
Bt Genes in GMOs
  • Characteristics:
    • A) Encode a protoxin versus a toxin.
    • D) Cause pores in insect guts.
Plant Disease Resistance
  • Most Commonly Planted GMOs:
    • Fungal resistant trees.
    • Most common gene for virus resistance: C) Virus coat protein.
Oxalate Oxidase Genes in Chestnuts
  • These genes help increase resistance by:
    • A) Degrading oxalic acid and B) Preventing acidification.

Seed Harvesting and Stratification

  • Importance of timing:
    • A) Immature seeds have reduced germination.
    • B) Risks from animals.
Measuring Seed Maturity
  • Methods:
    • B) Monitoring changes in color
    • D) Determining specific gravity by weight and volume.
Seed Stratification Requirements
  • Requirements Include:
    • B) Variable lengths depending on species.
    • C) Cold storage required.

Seedling Production: Bare Root vs. Container Grown

  • Advantages of Bare Root:
    • A) Lower production cost.
    • B) Less shipping complexity.
  • Advantages of Container Grown:
    • B) Flexibility in poor soil locations.

Molecular Markers

  • Good Marker Characteristics:
    • A) Distributed throughout the genome
    • D) Co-dominant.
Polymorphism Examples
  • Examples of Polymorphism:
    • A) Restriction Fragment Length Polymorphism
    • B) Simple Sequence Repeat.
Progeny Test Evaluation
  • Purpose:
    • A) Genetic evaluation to rogue existing orchards.
    • C) Typically planted in representative locations.

Clonal Seed Orchards

  • Develop via vegetative propagation.
  • Measure regularly to rogue poor trees.
Family Forestry
  • Involves large-scale deployment of full-sib families but does not achieve the same gains as open-pollinated seed.
Seed Production Areas (SPAs)
  • A) Natural stands that are improved by thinning.
Directed Seed Collections
  • Progeny tests guide selection of the best trees for seed collections.