Antibiotic biocontrol — Streptomyces griseochromogenes is reported to show a potent curative effect against which plant disease?
-
ARice blast disease (Pyricularia oryzae/Magnaporthe oryzae)
-
BYellow blight of maize
-
CMilo disease of soybean
-
DEye spot of sugarcane
-
ELate blight of potato
Answer
Correct Answer: Rice blast disease (Pyricularia oryzae/Magnaporthe oryzae)
Explanation
Introduction / Context:Members of the genus Streptomyces produce many agriculturally important antibiotics. Streptomyces griseochromogenes is historically linked with an antibiotic effective against the rice blast fungus, a major pathogen of rice worldwide.
Given Data / Assumptions:
- Rice blast (caused by Pyricularia/Magnaporthe oryzae) threatens yield and requires integrated control.
- Antibiotics from Streptomyces have been explored for plant disease management.
- Blasticidin S is a well-known product associated with S. griseochromogenes.
Concept / Approach:Blasticidin S exhibits strong activity against rice blast, making S. griseochromogenes notable in the history of plant disease control. Recognizing pathogen–antibiotic pairings is useful in agribiotech and plant pathology exams.
Step-by-Step Solution:
Identify the antibiotic producer: S. griseochromogenes.Recall its primary agricultural application: control of rice blast.Select rice blast as the correct associated disease.Verification / Alternative check:Historical literature reports blasticidin S from S. griseochromogenes with efficacy against rice blast in paddy systems.
Why Other Options Are Wrong:
- Yellow blight of maize, soybean milo disease, and eye spot of sugarcane have different etiologies and control measures not centered on blasticidin S from this species.
Common Pitfalls:Confusing producers of polyoxins or kasugamycin with blasticidin S; multiple Streptomyces species yield distinct antifungals.
Final Answer:Rice blast disease (Pyricularia oryzae/Magnaporthe oryzae)