Question

Which of the following is NOT a serious limitation for conserving the plant genetic resources under in-vitro repositories?

• A. Genetic stability may be compromised over time due to accumulation of somaclonal variations.
• B. High cost associated with establishment and maintenance of in-vitro collections.
• C. Limited capacity to conserve large collections compared to field genebanks.
• D. Vulnerability to catastrophic events such as power outages or equipment failure.

Hint:

In-vitro systems are highly valued specifically because they overcome the massive spatial and land constraints of field genebanks.
Therefore, space and capacity are major advantages of in-vitro conservation, not limitations.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
In-vitro conservation involves conserving plant tissues, cells, or organs under sterile, controlled artificial environments in laboratory culture tubes or vessels.
This method is primarily utilized for vegetatively propagated crops, recalcitrant-seeded species, and sterile plants.

Step 2: Detailed Explanation:
Let us evaluate each of the statements to identify which one is NOT a limitation:
- Option (A): Prolonged subculturing of plant tissues in-vitro exposes them to physiological and chemical stresses, which can induce mutations, chromosomal rearrangements, and epimutational shifts.
This phenomenon, known as somaclonal variation, compromises the genetic integrity of conserved accessions, making genetic instability a major limitation of in-vitro repositories.
- Option (B): Setting up and running tissue culture laboratories requires expensive specialized equipment, constant chemical supplies, and skilled scientific personnel, creating high operational costs.
Thus, high cost is indeed a serious limitation.
- Option (C): In-vitro conservation is highly space-efficient.
Thousands of plant accessions can be stored in small test tubes on a single culture shelf in a single room.
By comparison, a field genebank requires hectares of arable land, intensive manual labor, and exposes plants to weather and pests.
Therefore, in-vitro systems actually have a much higher capacity to conserve large collections per unit space compared to field genebanks.
Stating that in-vitro repositories have "limited capacity" compared to field genebanks is inaccurate, making this a non-limitation.
- Option (D): Since tissue cultures are entirely dependent on strictly controlled temperatures, light cycles, and airflow, any power failure or equipment malfunction can cause catastrophic, irreversible loss of the entire collection.
Thus, vulnerability to infrastructure failure is a major limitation.

Step 3: Final Answer:
Limited capacity to conserve large collections compared to field genebanks is NOT a limitation of in-vitro conservation.