In stability analysis, β = 0 indicates:

Correct option is D

What is Stability Analysis?
Stability analysis in plant breeding assesses how consistently a genotype performs across different environments (locations, seasons, management).
The most commonly used model is the Eberhart and Russell (1966) model, which evaluates genotype × environment interaction.
�� Key Parameters in Stability Analysis:
Mean Performance – The average yield or trait value across environments.
Regression Coefficient (β) – Measures responsiveness of a genotype to changing environments.
Deviation from Regression (S²d) – Measures predictability.
�� Interpretation of β (Beta):
β = 1.0: Average responsiveness → genotype is stable and responsive to environmental change (average stability).
β > 1.0: High responsiveness → performs better in favorable environments (below average stability in poor conditions).
β < 1.0: Low responsiveness → suited for poor or unfavorable environments (above average stability in poor environments).
β = 0: No response to environmental change → the genotype’s performance does not vary at all across environments.
This condition is termed absolute stability.
�� Explanation of Options:
(a) Average stability – ❌ This corresponds to β = 1
(b) Above average stability – ❌ For β < 1, suited to poor environments
(c) Below average stability – ❌ For β > 1, suited to rich environments
(d) Absolute stability – ✅ Correct, means performance is constant across all environments (β = 0)