Seed Science and Technology- ICAR JRF/SRF 2024

• Induction of Staminate Flowers in Gynoecious Lines: Gynoecious cucumber lines (Cucumis sativus) produce only pistillate (female) flowers, preventing natural selfing.
• Maintenance: Foliar application of Silver Nitrate ($AgNO_3$) or Silver Thiosulfate (STS) acts as a potent inhibitor of ethylene action, inducing transient male (staminate) flowers that produce viable pollen for self-pollination. (Correct answer: Option 1)

• Working Principles of Seed Cleaning and Separation Machinery:
• Specific Gravity Separator: Separates seed admixtures based on differences in specific density and terminal velocity in an air stream $\rightarrow$ effectively removes (I) Partially filled achenes / light, shriveled seeds.
• Indented Cylinder Separator: Employs centrifugal force and hemispherical pockets on a rotating drum to lift and separate particles based on length differences $\rightarrow$ removes (II) Broken caryopsis / short weed seeds.
• Dodder Mill (Velvet Roll Mill): Separates seeds utilizing contrasting surface roughness and texture differences via counter-rotating flannel/velvet cloth-covered rollers $\rightarrow$ removes (III) Rough surfaced admixture.
• Spiral Separator: Operates purely on gravitational acceleration and degree of roundness/centrifugal displacement $\rightarrow$ efficiently separates spherical seeds from flat or angular particles, isolating (IV) Splits in soybean.
• 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)

• Quality Declared Seed (QDS) System: Introduced by the Food and Agriculture Organization (FAO) in 1993.
• Objective: Provides an organized, low-cost seed quality assurance protocol for developing countries that do not have the institutional capacity for full conventional seed certification, requiring at least 10% of seed fields to be officially verified. (Correct answer: Option 4)