Question

For estimation of mid-parent heterosis, the genotypes included in the trials are-
A. F1 hybrids
B. Female parents
C. Male parents
D. Check variety
E. Top cross hybrid
Choose the correct answer from the options given below:

• A. A, B and D only
• B. A, B and C only
• C. A, B and E only
• D. B, C and D only

Hint:

Heterosis Types:
1. Mid-parent Heterosis: F\( _1 \) vs Average of Parents ($P_1$, $P_2$).
2. Better-parent Heterosis (Heterobeltiosis): F\( _1 \) vs Superior Parent ($P_s$).
3. Standard Heterosis: F\( _1 \) vs Commercial Check Variety.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
Heterosis, or hybrid vigor, is the superiority of an F\( _1 \) hybrid over its parents. There are different ways to measure this, depending on which "standard" or "parent" is used for comparison.

Step 2: Key Formula or Approach:
The formula for Mid-parent Heterosis ($H_{mp}$) is:
\[ H_{mp} = \frac{F_1 - MP}{MP} \times 100 \]
Where $MP$ (Mid-Parent Value) = $\frac{P_1 + P_2}{2}$.
Detailed Explanation:

• Requirement for Estimation: To calculate the mid-parent value, one must grow and record the performance of the female parent (B) and the male parent (C) in the same environment as the hybrid.

• F1 Hybrid (A): The hybrid itself must be grown to provide the $F_1$ value for comparison.

• Other Terms:
- Check Variety (D) is used to estimate Standard Heterosis or Economic Heterosis.
- Top Cross Hybrid (E) is a specific type of cross used to test combining ability, not for standard heterosis estimation.
Final Answer:
To estimate mid-parent heterosis, the essential genotypes are the F\( _1 \), the Female parent, and the Male parent.
Therefore, A, B, and C only are required.
The correct option is (B).