Consider the following techniques/ phenomena: 1. Budding and graftin

Consider the following techniques/ phenomena:

  • 1. Budding and grafting in fruit plants
  • 2. Cytoplasmic male sterility
  • 3. Gene silencing

Which of the above is/are used to create transgenic crops?

1 only
2 and 3
1 and 3
None
This question was previously asked in
UPSC IAS – 2014
The correct answer is B) 2 and 3. Transgenic crops are created through genetic engineering, which involves introducing or altering genes in a plant.
1. Budding and grafting in fruit plants: These are methods of asexual (vegetative) propagation used to combine traits from different plants or propagate desired varieties. They do not involve introducing foreign genes to create a transgenic organism. This is not used to create transgenic crops.
2. Cytoplasmic male sterility: While CMS itself is a biological phenomenon used in hybrid breeding, genetic engineering techniques *can* be used to introduce or restore male sterility genes (like the barnase/barstar system), thereby creating transgenic plants with engineered CMS. In this context, the concept is linked to the creation of transgenics for breeding purposes.
3. Gene silencing: Techniques like RNA interference (RNAi) are methods of gene silencing where the expression of a specific gene is inhibited. These techniques are widely used in genetic engineering to modify plants, for example, to reduce levels of undesirable compounds, improve nutritional value, or confer resistance. Using gene silencing to modify a plant *creates* a transgenic crop.
Creating transgenic crops involves techniques for gene isolation, vector construction, gene transfer (e.g., Agrobacterium-mediated transformation, gene gun), and selection of transformed cells/plants. Gene silencing is a tool used in the genetic modification process. While CMS is a trait, the methods to engineer it into a plant fall under genetic engineering techniques used for creating transgenics.