Agronomy Plant Genetics and Breeding

Question 1

What is a hybrid variety in crop production?

Accepted Answer

The F1 offspring of two inbred parent lines

Answer

A hybrid variety is the first-generation (F1) offspring produced by crossing two genetically distinct inbred parent lines, exhibiting hybrid vigor.

Question 2

What is 'heterosis' (hybrid vigor) in plant breeding?

Accepted Answer

Superior performance of F1 hybrids over parental averages

Answer

Heterosis refers to the superior performance of F1 hybrid offspring compared to the average of their parent inbred lines.

Question 3

Which breeding method is most commonly used to develop new inbred lines for hybrid corn production?

Accepted Answer

Selfing (self-pollination) for multiple generations

Answer

Repeated self-pollination over 6–8 generations produces highly homozygous inbred lines used as parents in hybrid seed production.

Question 4

What does the term 'quantitative trait' mean in plant genetics?

Accepted Answer

A trait controlled by many genes showing continuous variation

Answer

Quantitative traits like yield and plant height are controlled by many genes with small individual effects and show continuous variation in populations.

Question 5

Backcrossing in plant breeding is primarily used to do what?

Accepted Answer

Transfer a single trait into an elite variety while preserving its background

Answer

Backcrossing involves repeated crosses to the recurrent (elite) parent to recover its genome while retaining a desired trait from the donor parent.

Agronomy Practice Test

Agronomy Practice Test

Agronomy Plant Genetics and Breeding