Question

Arrange the following classes of seeds in ascending order of their genetic purity percentage:
A. Certified seed
B. Breeder seed
C. Foundation seed
D. Nucleus seed

• A. D, C, A, B
• B. A, C, B, D
• C. C, A, B, D
• D. A, B, C, D

Hint:

Seed multiplication pedigree and genetic purity standards:
1. Nucleus Seed: $100\%$ pure (highest)
2. Breeder Seed: $100\%$ pure (golden yellow tag)
3. Foundation Seed: $\ge 99.5\%$ pure (white tag)
4. Certified Seed: $\ge 99.0\%$ pure (azure blue tag)
Ascending order is Certified $<$ Foundation $<$ Breeder $<$ Nucleus.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
In seed technology, a structured seed multiplication chain (pedigree system) is used to maintain genetic identity and purity across generations.
Each class of seed must meet specific minimum genetic and physical purity standards set by certification agencies.

Step 2: Detailed Explanation:
Let us look at the genetic purity standards for each class of seed in the multiplication chain:
A. Certified seed:
This is the progeny of foundation seed and is distributed to farmers for commercial crop production.
Its genetic purity standard is the lowest among the four classes, typically required to be at least 99.0% to 99.5% depending on the crop.
C. Foundation seed:
This is the progeny of breeder seed and is produced under the supervision of seed certification agencies.
Its minimum genetic purity standard is higher than certified seed, usually required to be at least 99.5% to 99.8%.
B. Breeder seed:
This is the progeny of nucleus seed and is produced directly by the originating breeder.
It is used to produce foundation seed and is required to have 100% genetic purity.
D. Nucleus seed:
This is the initial, hand-selected seed produced by the originating plant breeder.
It represents the highest level of genetic purity, maintained at an absolute 100% genetic purity, and is used to produce breeder seed.

Step 3: Final Answer:
Arranging the classes of seeds in ascending order (lowest to highest) of their genetic purity:
Certified seed (A) $<$ Foundation seed (C) $<$ Breeder seed (B) $\le$ Nucleus seed (D).
This sequence corresponds to the order A, C, B, D, which is Option (B).