Question

Match List-I with List-II:
\includegraphics[width=0.6\linewidth]{25.png Choose the correct answer from the options given below:

• (A) - (III), (B) - (IV), (C) - (II), (D) - (I)
• (A) - (IV), (B) - (III), (C) - (I), (D) - (II)
• (A) - (IV), (B) - (III), (C) - (II), (D) - (I)
• (A) - (III), (B) - (IV), (C) - (I), (D) - (II)

Hint:

Flor's Gene-for-gene model (Flax rust) and Painter's mechanisms of insect resistance (Antibiosis, Antixenosis, Tolerance) are two of the most frequently asked historical milestones in agricultural entrance exams.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Plant breeding, plant pathology, and entomology have been shaped by several key concepts and hypotheses proposed by pioneering scientists.
These include genetic models of host-pathogen interactions, genetic diversity, and insect-host relationships.

Step 2: Detailed Explanation:
Let us correlate the scientific concepts with the investigators who proposed them:
1. Horizontal resistance (A):
J. E. Vander Plank introduced the concepts of "vertical" (race-specific, oligogenic) and "horizontal" (non-race-specific, polygenic) resistance in his classical work on plant disease epidemiology.
Thus, (A) matches with (IV).
2. Gene-for-gene hypothesis (B):
Harold H. Flor proposed this hypothesis based on his studies on flax rust (Melampsora lini).
He postulated that for each gene conditioning resistance in the host, there is a complementary gene conditioning virulence in the pathogen.
Thus, (B) matches with (III).
3. Law of parallel variation (C):
N. I. Vavilov formulated the "Law of Homologous Series in Variation."
He noted that closely related plant species and genera show parallel patterns of genetic variation.
Thus, (C) matches with (I).
4. Mechanism of insect resistance (D):
R. H. Painter is widely regarded as the father of host plant resistance to insects.
He classified the mechanisms of insect resistance into three categories: non-preference (antixenosis), antibiosis, and tolerance.
Thus, (D) matches with (II).

Step 3: Final Answer:
The correct matching sequence is (A)-(IV), (B)-(III), (C)-(I), and (D)-(II). This corresponds to option (B).