Question

Match the LIST-I with LIST-II and choose the correct answer from the options given below: \[ \begin{array}{|l|l|} \hline \textbf{LIST I (Common powdery mildews)} & \textbf{LIST II (Causal organism)} \\ \hline A.\ \text{Powdery mildews of barley} & I.\ \text{Cercosphaera leucotricha} \\ B.\ \text{Powdery mildews of peas} & II.\ \text{Uncinula necator} \\ C.\ \text{Powdery mildews of grape vines} & III.\ \text{Erysiphe polygoni} \\ D.\ \text{Powdery mildews of apple} & IV.\ \text{Erysiphe graminis var. hordei} \\ \hline \end{array} \]

• A. A - I, B - II, C - III, D - IV
• B. A - I, B - III, C - II, D - IV
• C. A - I, B - II, C - IV, D - III
• D. A - IV, B - III, C - II, D - I

Hint:

Mnemonic: {Barley–hordei}, {Pea–polygoni}, {Grape–Uncinula}, {Apple–leucotricha}. Match host cues to species epithets.

Answer 1

The Correct Option is D

Step 1: Identify host–pathogen pairings for prevalent powdery mildews.
Barley powdery mildew is primarily associated with *Erysiphe graminis var. hordei*, a host-specific strain targeting cereals.
Pea powdery mildew is commonly attributed to *Erysiphe polygoni* in horticultural literature for legumes.
Grape powdery mildew originates from *Uncinula necator*, a widely recognized pathogen in vineyards globally.
Apple powdery mildew is caused by the organism historically classified as *Sphaerotheca* or *Podosphaera leucotricha*. In the provided list, it is represented as *Cercosphaera leucotricha*, denoting the identical disease entity for matching purposes.
Step 2: Execute the matching process.
A (barley) → IV (*Erysiphe graminis var. hordei*).
B (peas) → III (*Erysiphe polygoni*).
C (grape vines) → II (*Uncinula necator*).
D (apple) → I (*Cercosphaera leucotricha*).
Step 3: Finalize the conclusion.
The accurate correspondence is A - IV, B - III, C - II, D - I, aligning with option (4).