Question:
Given below are two statements, one is labelled as Assertion (A) and other is labelled as Reason (R).
Assertion (A) : Nucellar embryony has been a major obstacle in citrus breeding
Reason (R) : Nucellar embryos arise from somatic cells of the nucellus, they are asexual progenies and not required by the breeder.
In light of above statements, choose the most appropriate answers from the options given below.
Given below are two statements, one is labelled as Assertion (A) and other is labelled as Reason (R).
Assertion (A) : Nucellar embryony has been a major obstacle in citrus breeding
Reason (R) : Nucellar embryos arise from somatic cells of the nucellus, they are asexual progenies and not required by the breeder.
In light of above statements, choose the most appropriate answers from the options given below.
Assertion (A) : Nucellar embryony has been a major obstacle in citrus breeding
Reason (R) : Nucellar embryos arise from somatic cells of the nucellus, they are asexual progenies and not required by the breeder.
In light of above statements, choose the most appropriate answers from the options given below.
Show Hint
To identify zygotic seedlings from nucellar clones, breeders use morphological markers (like trifoliate leaves if a trifoliate male parent is used) or molecular markers (like SSRs or PCR) to screen seedlings early.
Updated On: Jul 23, 2026
- Both (A) and (R) are correct and (R) is the correct explanation of (A)
- Both (A) and (R) are correct but (R) is not the correct explanation of (A)
- (A) is correct but (R) is not correct
- (A) is not correct but (R) is correct
Show Solution
Verified By Collegedunia
The Correct Option is A
Solution and Explanation
Step 1: Understanding the Concept:
Nucellar embryony is a form of apomixis where maternal embryos develop directly from somatic cells of the nucellus surrounding the embryo sac.
In citrus breeding, this trait presents both unique advantages for rootstock propagation and major challenges for hybridization.
Step 2: Detailed Explanation:
Let us analyze the assertion and reason:
Assertion (A): "Nucellar embryony has been a major obstacle in citrus breeding"
This statement is correct.
When breeders cross different citrus varieties to create new hybrids, they want the zygotic (hybrid) embryo to develop.
However, in polyembryonic maternal parents, the somatic nucellar embryos often develop faster and crowd out the fragile zygotic embryo.
This makes it difficult for breeders to recover true hybrid seedlings, as most of the sprouted plants end up being maternal clones.
Reason (R): "Nucellar embryos arise from somatic cells of the nucellus, they are asexual progenies and not required by the breeder."
This statement is correct.
Because nucellar embryos develop from somatic maternal tissue without fertilization, they are genetically identical to the female parent (clones).
They do not contain any new genetic combinations.
For a breeder trying to select novel, improved genotypes, these maternal clones are redundant and complicate the selection process.
This biological fact is precisely why nucellar embryony is a major obstacle in breeding programs.
Thus, (R) is the correct explanation of (A).
Step 3: Final Answer:
Both (A) and (R) are correct, and (R) is the correct explanation of (A).
This corresponds to Option (A).
Nucellar embryony is a form of apomixis where maternal embryos develop directly from somatic cells of the nucellus surrounding the embryo sac.
In citrus breeding, this trait presents both unique advantages for rootstock propagation and major challenges for hybridization.
Step 2: Detailed Explanation:
Let us analyze the assertion and reason:
Assertion (A): "Nucellar embryony has been a major obstacle in citrus breeding"
This statement is correct.
When breeders cross different citrus varieties to create new hybrids, they want the zygotic (hybrid) embryo to develop.
However, in polyembryonic maternal parents, the somatic nucellar embryos often develop faster and crowd out the fragile zygotic embryo.
This makes it difficult for breeders to recover true hybrid seedlings, as most of the sprouted plants end up being maternal clones.
Reason (R): "Nucellar embryos arise from somatic cells of the nucellus, they are asexual progenies and not required by the breeder."
This statement is correct.
Because nucellar embryos develop from somatic maternal tissue without fertilization, they are genetically identical to the female parent (clones).
They do not contain any new genetic combinations.
For a breeder trying to select novel, improved genotypes, these maternal clones are redundant and complicate the selection process.
This biological fact is precisely why nucellar embryony is a major obstacle in breeding programs.
Thus, (R) is the correct explanation of (A).
Step 3: Final Answer:
Both (A) and (R) are correct, and (R) is the correct explanation of (A).
This corresponds to Option (A).
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