Rapid Ragi: A speed breeding protocol for finger millet.

Area of Science:

• Agricultural Science
• Plant Breeding
• Genomics

Background:

• Climate change necessitates resilient, nutritious crops like finger millet (ragi) for global food security.
• Rapid development of improved and adapted finger millet cultivars is crucial.
• Genomics-assisted breeding and rapid generation advancement are key modern techniques.

Purpose of the Study:

• To develop a repeatable and cost-effective speed breeding protocol for finger millet.
• To optimize agronomic and physiological conditions for accelerated early generation advancement.

Main Methods:

• Modulated photoperiod (9 hours), temperature (29°C ± 2°C), and humidity (70%).
• Controlled plant density (105 plants/1.5 sq. ft.), nutrient application (0.17% Hoagland's No. 2 solution), and irrigation.
• Harvesting at physiological maturity.

Main Results:

• Reduced finger millet maturity time by 28-54 days across different maturity groups.
• Validated the protocol in segregating populations, enabling 4-5 generations per year compared to 1-2 under field conditions.
• Demonstrated a repeatable and cost-effective speed breeding approach.

Conclusions:

• The developed speed breeding protocol significantly shortens the breeding cycle, leading to increased genetic gain.
• Facilitates rapid development of recombinant inbred lines (RILs).
• Enables high-throughput phenotyping and early generation genotyping for accelerated selection processes.