Given below are a few statements regarding gene actions observed in plants.

A. In terms of pollination, self-pollinated species often exhibit additive gene action.
B. Non-additive gene action is less prevalent in cross-pollinated species.
C. Simply inherited (qualitative, oligogenic) traits predominantly exhibit non-additive and epistatic gene action.
D. Genetic fixation of superior genes will be more difficult with dominance gene action.

Which one of the following options represents the combination of all correct statements?

Correct option is B

Sol.

• A is correct: Self-pollinated species typically show additive gene action, as homozygosity is high, and traits accumulate in an additive manner.

• B is incorrect: Non-additive gene action is actually more prevalent in cross-pollinated species due to heterozygosity and interactions like dominance and epistasis.

• C is correct: Simply inherited qualitative traits often show non-additive and epistatic interactions, influencing phenotype expression.

• D is correct: Genetic fixation of superior genes is harder under dominance gene action because heterozygotes mask recessive alleles, slowing selection progress.

Information Booster:

• Additive gene action involves cumulative effects of alleles and is more easily fixed through selection.

• Non-additive gene action includes dominance and epistasis, often complicating breeding efforts in cross-pollinated species.

• Qualitative traits controlled by few genes often show epistatic interactions affecting trait expression.

• Dominance can mask recessive alleles, affecting the rate of genetic gain in breeding programs.