Seed Science and Technology- ICAR JRF/SRF 2024

• Two-Line Hybrid Seed Production: A hybrid breeding system that eliminates the need for maintainer (B) lines by utilizing environmentally sensitive genic male sterility (EGMS—TGMS or PGMS) or functional male sterility.
• Commercial Feasibility: Successfully established and commercially exploited in Brinjal (Solanum melongena) utilizing functional male sterility (positional sterility/exserted stigma) or TGMS systems. (Correct answer: Option 1)

• Assertion (A) is True: Seed vigour testing provides a more sensitive and reliable estimate of field emergence and stand establishment under suboptimal or stressful environmental conditions than standard laboratory germination testing.
• Reason (R) is True: Standard germination tests are conducted under strictly controlled, optimum moisture, aeration, and temperature conditions in the laboratory, which mask physiological deterioration that becomes evident only under field stress.
• Relationship: Because standard germination tests evaluate potential germination only under ideal conditions, they fail to reveal early cellular degradation and decline in vigour that dictate field performance; thus, Reason (R) correctly explains Assertion (A).
• Conclusion: Both (A) and (R) are true and (R) is the correct explanation of (A) (Option 1).

Correct option: (1) Both (A) and (R) are true and (R) is the correct explanation of (A)

• Physiological Disorders and Nutrient Interactions in Seed Crops:
• Pea (Pisum sativum): Susceptible to hollow heart and bleaching; high nitrogen application leads to bleaching of pea seeds and reduces storability $\rightarrow$ (I)
• Turnip (Brassica rapa): Boron deficiency leads to brown heart (water core/rot) in cruciferous root crops $\rightarrow$ (II)
• Bean (Phaseolus vulgaris): Manganese deficiency causes marsh spot characterized by necrotic brown spots on internal cotyledon surfaces $\rightarrow$ (III)
• Beetroot (Beta vulgaris): Boron deficiency leads to heart rot and internal black spot $\rightarrow$ (IV)
• Systematic Match: (A)-(I), (B)-(II), (C)-(III), (D)-(IV) corresponds to Option 4.

Correct option: (4) (A) - (1), (B)~ (I), (C) - (ill), (D)- (V)