Question

Given below are two statements:
Statement (I): Bringing together two or more genes governing a single trait, especially resistance to disease is known as gene pyramiding
Statement (II) : The use of molecular markers greatly facilitates gene pyramiding as it minimises the need for disease tests and progeny test
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are true.
• B. Both Statement (I) and Statement (II) are false.
• C. Statement (I) is true but Statement (II) is false.
• D. Statement (I) is false but Statement (II) is true.

Hint:

Gene Pyramiding: Stacking multiple beneficial genes (e.g., for disease resistance) into one plant variety to enhance a trait.
Molecular Markers (Marker-Assisted Selection - MAS): DNA-based tools that help breeders identify plants carrying specific genes without always needing to grow them out and test them phenotypically (e.g., by disease exposure). This makes gene pyramiding faster and more efficient.

Answer 1

The Correct Option is A

Statement (I): Bringing together two or more genes governing a single trait, especially resistance to disease is known as gene pyramiding. This statement is true. Gene pyramiding is a plant breeding strategy that aims to combine multiple genes, each conferring resistance to a particular pathogen or pest (or contributing to a desirable complex trait), into a single cultivar. The goal is often to achieve more durable and broader-spectrum resistance than what a single resistance gene might provide. Statement (II): The use of molecular markers greatly facilitates gene pyramiding as it minimises the need for disease tests and progeny test. This statement is also true. Traditional gene pyramiding relies heavily on phenotypic screening (e.g., exposing plants to the disease to see if they are resistant) and extensive progeny testing, which can be time-consuming, labor-intensive, and sometimes unreliable if multiple genes mask each other's effects or if environmental conditions affect disease expression. Molecular markers (DNA sequences linked to the genes of interest) allow breeders to directly select for the presence of desired resistance genes in individual plants, even in the absence of the pathogen. This is called Marker-Assisted Selection (MAS). MAS significantly speeds up the pyramiding process, improves accuracy, and can reduce the reliance on extensive phenotypic screening, thus minimizing (though not always completely eliminating) the need for some disease tests and progeny tests. Since both statements are true and accurately describe gene pyramiding and the role of molecular markers in it, option (1) is correct. Both Statement (I) and Statement (II) are true.