Broad Heritability Using Breeder's Equation Calculator

Breeder's Equation:

\[ H^2 = \frac{\text{var}(G_{Aa}, G_{aa}, G_{AA})}{\text{var}(P_{aa}, P_{AA}, P_{Aa})} \]

Genotype of (Aa) Allele:

Genotype of (aa) Allele:

Genotype of (AA) Allele:

Phenotype of (aa) Allele:

Phenotype of (AA) Allele:

Phenotype of (Aa) Allele:

Broad Sense Heritability (H²):

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1. What is Broad Sense Heritability?

Broad Sense Heritability reflects all the genetic contributions to a population's phenotypic variance including additive, dominant, and epistatic effects. It represents the proportion of phenotypic variance attributable to genetic variance.

2. How Does the Calculator Work?

The calculator uses the Breeder's Equation:

\[ H^2 = \frac{\text{var}(G_{Aa}, G_{aa}, G_{AA})}{\text{var}(P_{aa}, P_{AA}, P_{Aa})} \]

Where:

\( G_{Aa} \) — Genotype value of heterozygous individual
\( G_{aa} \) — Genotype value of recessive homozygous individual
\( G_{AA} \) — Genotype value of dominant homozygous individual
\( P_{aa} \) — Phenotype value of recessive homozygous individual
\( P_{AA} \) — Phenotype value of dominant homozygous individual
\( P_{Aa} \) — Phenotype value of heterozygous individual

Explanation: The equation calculates the ratio of genetic variance to phenotypic variance, providing a measure of how much of the phenotypic variation is due to genetic factors.

3. Importance of Heritability Calculation

Details: Understanding heritability is crucial for plant and animal breeding programs, evolutionary biology studies, and genetic research. It helps predict response to selection and understand the genetic architecture of traits.

4. Using the Calculator

Tips: Enter genotype and phenotype values for all three genotypic classes (AA, Aa, aa). Ensure all values are valid numerical inputs representing the respective measurements.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between broad and narrow sense heritability?
A: Broad sense heritability includes all genetic variance (additive, dominant, epistatic), while narrow sense heritability only includes additive genetic variance.

Q2: What are typical heritability values?
A: Heritability ranges from 0 to 1. Values close to 1 indicate strong genetic control, while values close to 0 indicate environmental factors dominate.

Q3: When is this equation most useful?
A: This approach is particularly useful in controlled breeding experiments and genetic studies where genotype and phenotype data are available for different genetic classes.

Q4: Are there limitations to this calculation?
A: This method assumes normal distribution of traits and may be less accurate for traits with complex inheritance patterns or strong environmental interactions.

Q5: How does this relate to selection response?
A: Higher heritability values generally predict stronger response to selection in breeding programs, as more of the phenotypic variation is genetically determined.