Question

Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A) : Sweet potato is highly heterozygous with out-breeding habit.
Reason (R) : Self-incompatibility is evident in different sweet potato cultivars.
In light of the above statements, choose the correct answer from the options given below.

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• B. Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
• C. (A) is true but (R) is false.
• D. (A) is false but (R) is true.

Hint:

Sweet Potato Genetics (A): It's a hexaploid, highly heterozygous (diverse genes), and mainly out-breeds (cross-pollinates).
Self-Incompatibility (R): Sweet potato has a self-incompatibility system, meaning it usually can't self-pollinate.
Explanation: Self-incompatibility (R) forces out-breeding, which leads to and maintains high heterozygosity (A).

Answer 1

The Correct Option is A

Assertion (A): Sweet potato is highly heterozygous with out-breeding habit. This statement is true. Sweet potato (Ipomoea batatas) is a hexaploid (2n = 6x = 90) and is predominantly cross-pollinated (out-breeding), primarily by insects like bees. Due to its polyploid nature and out-breeding habit, sweet potato cultivars are typically highly heterozygous (possessing different alleles for many genes). Reason (R): Self-incompatibility is evident in different sweet potato cultivars. This statement is also true. Sweet potato exhibits a sporophytic self-incompatibility system. This means that pollen from a plant often cannot fertilize ovules of the same plant or other plants with the same S-alleles, thus enforcing out-crossing. Self-incompatibility is a common mechanism in many plant species to promote out-breeding and maintain heterozygosity. Is (R) the correct explanation of (A)? Yes, (R) is a correct explanation for the "out-breeding habit" part of (A) and contributes to the maintenance of high heterozygosity. Self-incompatibility (Reason R) is a primary genetic mechanism that enforces an out-breeding habit in sweet potato. This out-breeding, in turn, leads to and maintains a high level of heterozygosity (Assertion A) in the population. Therefore, both statements are true, and self-incompatibility (R) is a key reason for the out-breeding habit and consequent high heterozygosity (A) observed in sweet potato. Both (A) and (R) are true and (R) is the correct explanation of (A).