Lecture 8

  1. What is the Coefficient of Variation?
    is a measure of the relative variability of given populations

    CV = (σ/µ) x 100
  2. What is Heritability?
    • Heritability is the proportion of the observed variation in a progeny that is inherited
    • If genetic variation in a progeny is large in relation to the environmental variation, the heritability will be high
    • In other words, the trait is highly controlled by genetic factors and less by environmental factors
  3. How is Heritability estimated?
    • are based on partitioning the observed variance of a quantitative trait into genetically and environmentally controlled components
    • H = (VP - VE) / VP
  4. What is environmental variance?
    Phenotypic differences among individuals of the same genotype (Ve) caused by: Soil factors, Pest factors and climate factors
  5. Broad sense Heritability definition:
    (H) is estimated from the total genetic variance, without taking into consideration the components of genetic variance.
  6. Narrow sense Heritability definition:
    (h2)—takes into account the genetic variance components.
  7. Why use heritability estimates?
    • Determine relative importance of genetic effects (parent to offspring)
    • Determination of selection method
    • Predict gain from selection
  8. What is genetic gain?
    Expected gain in the mean of a population for a quantitative character by one generation of selection of a specified % of the desired individuals
Card Set
Lecture 8
plant breeding