Black (stem) rust of wheat is caused by
- Alternaria solani
- Ustilago nuda
- Puccinia graminis
- Xanthomonas oryzae
Answer
(3) Puccinia graminis
Solution
Black (stem) rust of wheat is caused by the rust fungus Puccinia graminis (Basidiomycetes); as per NCERT, Puccinia is a well-known rust fungus.
∵ Alternaria solani causes early blight of potato, Ustilago nuda causes loose smut of wheat and Xanthomonas oryzae (a bacterium) causes bacterial blight of rice,
∴ the pathogen is Puccinia graminis.
Answer: (3)