Potential gain from selection for yield stability in two grain sorghum populations

Area of Science:

• Agricultural Science
• Plant Breeding
• Genetics

Background:

• Achieving maximum crop yield in unpredictable environments necessitates selecting genotypes with consistent performance.
• Several genotype stability parameters exist but are rarely used for selection due to low heritability.

Purpose of the Study:

• To compare the relative efficiency of indirect selection using different stability parameters and indices for improving sorghum yield.
• To evaluate the effectiveness of stability parameters, mean yield, and their combinations for genotype selection.

Main Methods:

• Evaluated 200 S1 families from two sorghum populations across four dry-land environments over two years.
• Assessed stability parameters: coefficient of regression (b), deviation from regression (S d (2)), and AMMI principal components scores (PC).
• Developed and compared indices combining mean yield with stability parameters and indices based on yield in specific environments.

Main Results:

• Individual stability parameters showed low heritability and low genetic correlation with mean yield, resulting in low indirect selection efficiency.
• Indices combining mean yield with stability parameters demonstrated increased selection efficiency across all environments.
• Indices incorporating fewer environments (mean productivity, rank summation, selection index) were more resource-efficient than those using all environments.

Conclusions:

• While individual stability parameters are inefficient for indirect selection, indices combining them with mean yield enhance selection for high yield across environments.
• The development of effective selection indices is crucial for improving crop performance in variable agricultural conditions.
• Resource allocation in breeding programs should consider the efficiency of different index-based selection strategies.