Speed breeding short-day crops by LED-controlled light schemes

Area of Science:

• Agricultural Science
• Plant Biology
• Genetics

Background:

• Plant breeding is crucial for agricultural production, but long crop generation times hinder cultivar development.
• Existing speed breeding protocols are primarily for long-day crops, leaving a gap for short-day varieties.
• Developing new crop varieties is essential to address global food security challenges posed by population growth and climate change.

Purpose of the Study:

• To develop and validate a rapid speed breeding protocol for short-day crops.
• To demonstrate the efficacy of a customized LED lighting system for accelerating crop generation cycles.
• To enable multiple crop generations annually for key agricultural species.

Main Methods:

• Developed a speed breeding protocol utilizing light-emitting diodes (LEDs) with adjustable light intensity and quality.
• Optimized photoperiod (10 hours) and light spectrum (blue-enriched, far-red-deprived) for soybean, rice, and amaranth.
• Evaluated flowering and maturation times under the developed speed breeding conditions.

Main Results:

• Achieved up to five generations per year for soybean, with flowering in ~23 days and maturity in ~77 days.
• Demonstrated successful speed breeding for rice (flowering in ~60 days) and amaranth (flowering in ~35 days).
• Observed that specific light spectrum adjustments, including far-red light, influenced flowering time in rice and amaranth but not soybean.

Conclusions:

• A novel, rapid speed breeding system using tailored LED lighting is effective for short-day crops.
• This protocol accelerates crop development cycles without requiring advanced techniques like embryo rescue.
• The system's adaptability to multi-storey tray cultivation facilitates integration with genomics for enhanced breeding rates.