Question

Knot like bodies known as 'nodules' found in the root of groundnut plant are produced by

• A. Azospirillum
• B. Azotobacter
• C. Pseudomonas
• D. Rhizobium

Answer 1

The correct option is D Rhizobium

Ground nut is a leguminous crop. Rhizobium are rod shaped gram negative bacteria, whose infection in roots causes nodule formation in roots of leguminous plants. Azospirillum and Acetobacter are also important nitrogen fixers but they are not associated with roots of leguminous plants. Azotobacter is free living and Azospirillum is associated with roots of grasses. Pseudomonas is a denitrifying bacteria.

So, the correct answer is 'Rhizobium'