Question

Sharbati Sonora variety of wheat was obtained by

• A. Crossing with wild varieties of wheat
• B. Hybridization between wild varieties of wheat
• C. X-ray treatment
• D. Irradiation with gamma rays

Hint:

Sharbati Sonora is a classic example of physical mutagenesis in India.
It was developed from the Mexican red wheat variety 'Sonora 64' using gamma-ray irradiation to produce desirable amber-colored grains.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Mutation breeding is a valuable crop improvement technique where genetic variations are artificially induced using physical or chemical mutagens.
Sharbati Sonora is a historic mutant variety of wheat developed in India during the Green Revolution.

Step 2: Detailed Explanation:
During the mid-1960s, Mexican dwarf wheat varieties like 'Sonora 64' were introduced to India.
Although highly productive, 'Sonora 64' possessed red-colored grains, which were less preferred by Indian consumers who favored amber-colored grains for making chapati.
Dr. M. S. Swaminathan and his team at the Indian Agricultural Research Institute (IARI) subjected the red grains of 'Sonora 64' to mutation breeding.
They used physical mutagens, specifically gamma-ray irradiation, to induce genetic mutations.
This targeted mutation altered the pigment biosynthesis pathway, yielding an amber-seeded mutant variety named Sharbati Sonora.
Hence, this variety was obtained directly via irradiation of the parent variety with gamma rays.

Step 3: Final Answer:
Sharbati Sonora wheat variety was obtained by irradiation with gamma rays.