Which of the following growth substance act as a stimulant during nodule formation in leguminous plants? A. Ethylene B. ABA C. IAA D. Morphactin
Option C. Auxins are growth promoting phytohormones. Thimann, 1939, suggested that IAA is the stimulatory material for nodule formation because it is produced by Rhizobium. However, many soil microorganisms are capable of forming IAA without the production of nodule. Nodule formation appears to be a result of complex interplay between host plant and the bacterium.
