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Vegetable Speed Breeding
https://www.petiolepro.com/blog/a-comprehensive-guide-to-speed-breeding-with-examples/
A Comprehensive Guide to Speed Breeding (with Examples)
by Maryna Kuzmenko
Speed breeding is an innovative approach in plant science that aims to accelerate the development of new crop varieties. This method, originally developed by NASA for space agriculture, has found significant applications in terrestrial crop improvement programs.
1. Historical Context of Speed Breeding
Origins and Early Development
Speed breeding, a revolutionary technique in plant science, has its roots in space exploration. The concept was initially developed by NASA in the 1980s as part of their Controlled Ecological Life Support Systems (CELSS) program. The primary goal was to find efficient ways to grow crops in space, where resources are limited and time is of the essence.
NASA’s Contribution
1980s: NASA scientists begin experimenting with accelerated plant growth cycles.
1992: First successful implementation of extended photoperiods to speed up wheat breeding.
Dr. Gary Stutte, a principal investigator for NASA, played a crucial role in these early experiments. His team demonstrated that by manipulating light cycles, they could significantly reduce the time between wheat generations.
Transition to Terrestrial Applications
While the initial focus was on space agriculture, researchers quickly recognized the potential for terrestrial applications.
Key Milestones
Late 1990s: Australian scientists, inspired by NASA’s work, begin adapting the technique for Earth-based crop improvement.
2001: Dr. Lee Hickey and his team at the University of Queensland start developing speed breeding protocols for various crops.
2007: First published results demonstrating the successful application of speed breeding in wheat.
The technique has undergone significant refinement since its inception:
2010-2015: Development of optimized light spectra and intensities for different crop species.
2017: Publication of a landmark paper in Nature Plants, detailing a standardized speed breeding protocol.
2018-present: Integration with other breeding technologies like genomic selection and CRISPR gene editing.
Global Adoption and Impact
Speed breeding has gained traction worldwide, with research institutions and companies adopting the technique:
Europe: John Innes Centre in the UK becomes a hub for speed breeding research.
Asia: IRRI (International Rice Research Institute) adapts the technique for rice breeding.
Africa: ICRISAT incorporates speed breeding in its legume improvement programs.
Current State and Future Outlook...
Optimizing protocols for a wider range of crop species
Reducing energy costs and improving sustainability
Integrating artificial intelligence for more efficient breeding decisions
2. Theoretical Foundations of Speed Breeding
Plant Physiology Principles
Photoperiodism
Key Physiological Processes
Photosynthesis
Extended light periods increase daily photosynthetic accumulation. Optimized light spectra enhance photosynthetic efficiency.
Role of phytohormones in heat tolerance in soybean. Hormones enhance seed germination, stem elongation, and enhanced photosynthetic pigments...
Hormonal Regulation...
(e.g., gibberellins, auxins)...
Circadian Rhythms...
Genetic Considerations...
Genetic Factors in Accelerated Breeding...
Flowering Time Genes...
Vernalization Requirements...
Photoperiod Sensitivity...
Genetic Stability and Variation...
Physiological Stress Management...
Heat Stress...
Oxidative Stress...
Nutrient Stress...
Theoretical Models
Crop Growth Models...
Gene Network Models...
Interdisciplinary Connections
Chronobiology...
Biophysics...
Computational Biology...
3. Detailed Methodology of Speed Breeding
3.1 Environmental Control Setup
3.1.1 Growth Chamber Specifications
Temperature range: 22°C ± 3°C
Relative humidity: 60-70%
CO2 concentration: 400-450 ppm
3.1.2 Lighting System
Light intensity: 400-600 μmol m⁻² s⁻¹ (PAR)
Photoperiod: 22 hours light / 2 hours dark
Light spectrum: Full spectrum LED with enhanced blue and red wavelengths
3.2 Plant Growth Media and Nutrition
3.2.1 Soil Mixture
70% peat moss, 20% vermiculite, 10% perlite
pH adjusted to 6.0-6.5
3.2.2 Nutrient Solution
Modified Hoagland’s solution
EC (Electrical Conductivity): 1.5-2.0 mS/cm
Application: Daily fertigation or automated drip system
3.3 Speed Breeding Protocol
3.3.1 Seed Preparation
Surface sterilization with 1% sodium hypochlorite solution
Pre-germination on moist filter paper for 24-48 hours
3.3.2 Planting
Transfer pre-germinated seeds to growth media
Maintain plant density at 100-150 plants/m²
3.3.3 Growth Phases Management
Vegetative phase: 14-21 days
Reproductive phase: 28-35 days
Seed maturation: 14-21 days
3.3.4 Pollination Techniques
Self-pollinating crops: Gentle shaking of plants to promote pollen dispersal
Cross-pollinating crops: Manual cross-pollination using fine brushes
3.3.5 Seed Harvesting
Monitor seed moisture content (target: 15-20%)
Hand-harvest mature seeds
Rapid drying at 35°C for 24-48 hours
3.4 Data Collection and Monitoring
3.4.1 Growth Parameters
Plant height: Measure every 7 days
Leaf area: Use portable leaf area meter bi-weekly
Biomass: Fresh and dry weight at key growth stages
3.4.2 Reproductive Development
Days to flowering
Number of flowers/inflorescences
Seed set rate
3.4.3 Yield Components
Number of seeds per plant
Thousand grain weight
Total yield per plant/unit area
3.5 Quality Control Measures
3.5.1 Genetic Purity
Molecular marker analysis for key traits
Phenotypic screening for off-types
3.5.2 Seed Quality Assessment
Germination tests: Standard and accelerated aging
Vigor tests: Electrical conductivity and tetrazolium
3.6 Troubleshooting Common Issues
3.6.1 Plant Stress Symptoms
Leaf chlorosis: Adjust nutrient solution or light intensity
Stunted growth: Check for root health and adjust environmental parameters
3.6.2 Poor Seed Set
Increase air circulation to promote pollen dispersal
Adjust temperature during flowering (species-specific)
3.6.3 Pest and Disease Management
Regular monitoring for early detection
Integrated pest management strategies adapted for controlled environments
3.7 Safety Considerations
3.7.1 Personal Protective Equipment...
3.7.2 Electrical Safety...
3.7.3 Chemical Safety...
Chapter 4: Case Studies and Future Directions in Speed Breeding
4.1 Introduction to Advanced Speed Breeding Techniques
4.2 Case Studies in Major Crops
4.2.1 Time Savings Across Various Crops
A comprehensive study from Lovely Professional University in India provided valuable insights into the application of speed breeding across multiple crop species. The researchers found that speed breeding can achieve 4-6 generations per year in various crops, compared to 1-2 generations using conventional methods. This significant increase in generational turnover has profound implications for accelerating crop improvement programs.
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Timeline comparison of speed breeding with other breeding techniques. Source: Nischay Chaudhary & Rubby Sandhu, 2024Timeline comparison of speed breeding with other breeding techniques. Source: Nischay Chaudhary & Rubby Sandhu, 2024
For wheat and barley, maintaining temperatures around 20-22°C allowed for up to eight generations per year, a remarkable improvement over traditional field-based breeding. In soybean studies, using a 10-hour photoperiod with specific light conditions resulted in plants maturing in just 77 days, enabling five generations per year. This rapid cycling through generations allows breeders to quickly incorporate and test new traits.
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Speed breeding coupled with modern breeding techniques. Source: Nischay Chaudhary & Rubby Sandhu, 2024Speed breeding coupled with modern breeding techniques. Source: Nischay Chaudhary & Rubby Sandhu, 2024
Rice breeding also saw significant advancements, with optimized seedling tray conditions and thinning processes achieving a germination rate of 95-100%. Perhaps most impressively, when coupled with genomic selection, speed breeding reduced the wheat breeding cycle from 3-7 years to just 1-2 years, dramatically shortening the time to develop new varieties...
4.2.2 Comprehensive Crop Studies...
4.6 Conclusion
Speed breeding, enhanced by AI and other advanced technologies, represents a significant leap forward in crop improvement. The case studies from India and elsewhere demonstrate its potential to dramatically reduce breeding cycles and accelerate the development of crops adapted to changing environmental conditions. As we move forward, addressing challenges related to sustainability, genetic diversity, and regulatory compliance will be crucial to fully realizing the benefits of these advanced breeding techniques. The future of agriculture looks brighter and more efficient, thanks to the innovative approaches of speed breeding and its integration with cutting-edge technologies.
In conclusion, these studies demonstrate the significant progress being made in stress breeding across various crops. By combining traditional breeding techniques with cutting-edge technologies and data analysis, researchers are paving the way for more resilient and productive crops in the face of climate change.
Videoshttps://www.youtube.com/watch?v=XB3H4Kg66ho
Speed Breeding: A Powerful Tool to Accelerate Crop Research & Breeding - Dr. Lee Hickey
https://www.youtube.com/watch?v=e7xbk24Dmsw
Speed Breeding in Vegetables crops By Dr SSDey IARI_feb26,20
https://www.youtube.com/watch?v=QAUJqmOkmKk
Speed Breeding: space-inspired technology driving crop improvement
https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1414860/full
Front. Plant Sci., 10 July 2024; Sec. Plant Breeding Volume 15 - 2024 |
Technology of plant factory for vegetable crop speed breeding
He, R., et al.
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Sustaining crop production and food security are threatened by a burgeoning world population and adverse environmental conditions. Traditional breeding methods for vegetable crops are time-consuming, laborious, and untargeted, often taking several years to develop new and improved varieties. The challenges faced by a long breeding cycle need to be overcome. The speed breeding (SB) approach is broadly employed in crop breeding, which greatly shortens breeding cycles and facilities plant growth to obtain new, better-adapted crop varieties as quickly as possible. Potential opportunities are offered by SB in plant factories, where optimal photoperiod, light quality, light intensity, temperature, CO2 concentration, and nutrients are precisely manipulated to enhance the growth of horticultural vegetable crops, holding promise to surmount the long-standing problem of lengthy crop breeding cycles. Additionally, integrated with other breeding technologies, such as genome editing, genomic selection, and high-throughput genotyping, SB in plant factories has emerged as a smart and promising platform to hasten generation turnover and enhance the efficiency of breeding in vegetable crops. This review considers the pivotal opportunities and challenges of SB in plant factories, aiming to accelerate plant generation turnover and improve vegetable crops with precision and efficiency.
https://www.biorxiv.org/content/10.1101/161182v1.full.pdf
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Watson, A., Ghosh, S., Williams, M. J., Cuddy, W. S., Simmonds, J., Rey, M. D., et al. (2018). Speed breeding is a powerful tool to accelerate crop research and breeding. Nat. Plants 4, 23–29. doi: 10.1038/s41477-017-0083-8
https://www.mdpi.com/2079-7737/11/2/275
Breeding More Crops in Less Time: A Perspective on Speed Breeding
by Kajal Samantara, K., et al.
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Abstract
Breeding crops in a conventional way demandss considerable time, space, inputs for selection, and the subsequent crossing of desirable plants. The duration of the seed-to-seed cycle is one of the crucial bottlenecks in the progress of plant research and breeding. In this context, speed breeding (SB), relying mainly on photoperiod extension, temperature control, and early seed harvest, has the potential to accelerate the rate of plant improvement. Well demonstrated in the case of long-day plants, the SB protocols are being extended to short-day plants to reduce the generation interval time. Flexibility in SB protocols allows them to align and integrate with diverse research purposes including population development, genomic selection, phenotyping, and genomic editing. In this review, we discuss the different SB methodologies and their application to hasten future plant improvement. Though SB has been extensively used in plant phenotyping and the pyramiding of multiple traits for the development of new crop varieties, certain challenges and limitations hamper its widespread application across diverse crops. However, the existing constraints can be resolved by further optimization of the SB protocols for critical food crops and their efficient integration in plant breeding pipelines.
3S’s Approaches for Crop Improvement and Genetic gain Vegetable Crops
Singh, S., et al.
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http://archive.scholarstm.com/id/eprint/120/1/137-Article%20Text-258-1-10-20220920.pdf
Vegetable Breeding Strategies
Ghuge, M., et al.
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https://www.frontiersin.org/articles/10.3389/fpls.2021.620420/pdf
Next-generation breeding strategies for climate-ready crops
Razzaq, A., et al.
[ PDF ]