Tree Improvement 101 - Module 3: Breeding Designs and Genetic Gain in Tree Improvement Programs
Webinar Details
When:
Apr 19, 2024 1:00 pm US/Eastern
Length: 01:00 (hh:mm)
Advance Registration NOT required.
View now on-demand.
Presenter(s):
- Carolyn "Carrie" Pike PhD - Regeneration Specialist, Reforestation, Nurseries, and Genetic Resources (RNGR) Program, USDA Forest Service - Eastern Region State, Private, and Tribal Forestry
- Trevor Walker - Assistant Professor of Forest Genetics, North Carolina State University
Virtual Event Format:
Group Viewing Available:
Module 3: This module will explore different types of selection in breeding programs.
We will unpack the concept of genetic gain and how its calculated using linear mixed models. We will also look at different breeding designs and how they are used to advance a population to the next generation.
Additional Information
Tree improvement programs rely on breeding to increase the amount of genetic gain within a breeding population. In the module we will investigate the concept of genetic gain, show ways it can be calculated, and describe different breeding approaches.
1. Genetic Gain:
- Genetic gain represents the improvement achieved in tree populations due to selective breeding.
- It quantifies the increase in desirable traits (e.g., growth rate, disease resistance) over successive generations.
- Factors influencing genetic gain:
- Selection Intensity: How rigorously superior trees are chosen.
- Heritability: The proportion of trait variation influenced by genetics.
- Population Size: Larger populations allow better selection.
- Breeding Value: The genetic contribution of an individual to its offspring.
- Linear mixed models are often used to calculate genetic gain.
- Breeding designs refer to the structured approaches used to enhance the genetic quality of tree populations. These designs guide how trees are selected, crossed, and propagated.
- Different breeding designs serve specific purposes and balance genetic diversity, heritability, and practical implementation.
- Some common breeding designs include:
- Advance Generation Breeding: Creating improved tree varieties populations over multiple generations through controlled crosses.
- Factorials: in this design, a set of mother genotypes are bred to a different set of father genotypes. This mating design may be used with dioecious trees.
- Diallels: In this design, the same set of genotypes is used as both maternal and pollen parents. This design only works with monoecious trees.
- Genetic Engineering (less commonly used): Introducing specific genes into tree populations.
In summary, breeding designs guide the practical implementation of tree improvement, while genetic gain measures the progress achieved through selective breeding efforts.
Learn More:
Woody Plant Seed Manual - Chapter 2: Genetic Improvement of Forest Trees (Clark W Lantz PhD)

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