Question

In a natural population of outbreeding plants, the variance of the total number of seeds per plant is 22. From the natural population, 40 plants are taken into the laboratory and developed into separate true- breeding lines by self-fertilization—with selection for high, low, or medium number of seeds—for 15 generations. The average variance in the fifteenth generation in each of the sets is about equal and averages 8.2 across all the sets. What is the broad-sense heritability for seed number in this population? (Show your intermediate calculations.)

Answer 1

The broad-sense heritability for seed number in the population is estimated to be approximately 37.27%, calculated using the genetic variance of 8.2 and the phenotypic variance of 22.

Step-by-step explanation:

To calculate the broad-sense heritability (H2) for seed number in this population, we use the following formula:

H2 = VG / VP

where VG is the genetic variance and VP is the phenotypic variance. The phenotypic variance is the initial variance observed in the natural population, so VP = 22. The genetic variance VG is estimated by the variance within the true-breeding lines after 15 generations of self-fertilization, which is 8.2.

Thus, the broad-sense heritability is:

H2 = 8.2 / 22

H2 = 0.3727 or 37.27%

The broad-sense heritability of seed number in this population is therefore estimated to be approximately 37.27%.