How breeders manage to grow 6 generations in a year: The Speed Breeding revolution

At the University of Queensland springs a growing revolution: Speed Breeding

NASA experiments to grow wheat in space were the inspiration for University of Queensland scientists to develop the world’s first ‘speed breeding’ procedures here on planet Earth. UQ Queensland Alliance for Agriculture and Food Innovation (QAAFI) Senior Research Fellow Dr Lee Hickey said the NASA experiments involved using continuous light on wheat which triggered early reproduction in the plants.

Speed breeding wheat under lights. UQ PhD student Amy Watson and Dr Lee Hickey.

Dr Lee Hickey in his speed breeding lab at University of Queensland, 20 June 2016.

At the very start of 2018, precisely on Jan. the 1st, was published in Nature Plants an article detailing the ins and outs of this method: “By using speed breeding techniques in specially modified glasshouses we can grow six generations of wheat, chickpea and barley plants, and four generations of canola plants in a single year – as opposed to two or three generations in a regular glasshouse, or a single generation in the field,” Dr Hickey said.

Dr Hickey was part of the team from the UQ School of Agriculture that began trialling speed breeding techniques to cut the length of plant breeding cycles more than 10 years ago.  

He said the level of interest in speed breeding led to his collaborators at the John Innes Centre and the University of Sydney to write the Nature Plants paper, which outlines all the protocols involved in establishing speed breeding systems and adaptation of regular glasshouse facilities.

UQ PhD student Amy Watson was a co-first author of the paper and conducted some of the key experiments that documented the rapid plant growth and flexibility of the system for multiple crop species.

Controlling all environmental conditions from seedling to maturation and from temperature to daylight time

Increasing the period of illumination through supplemental lighting greatly shortens crop generation time. Accelerating the maturation of grains enables as well to gain a dozen days. Increasing plant density proved pretty efficient to help the plant grow faster: "Wheat and barley genotypes were grown in 100-cell trays under both speed breeding and 12-hour day-neutral photoperiod conditions in the glasshouse. This equated to a density of approximately 900 plants per m2. Generation time was shorter than for plants grown at lower density".

Speed breeding accelerates generation time of major crop plants for research and breeding.

a, Compared to a glasshouse with a natural variable photoperiod (10–16 hours), where only 2–3 generations of wheat, barley, chickpea and canola can be achieved per year (right), speed breeding enables 4–6 generations of these crops to be grown in a year (left). These values are representative of relatively rapid cycling cultivars of each crop. b, Harvesting of immature spikes and drying them in an oven/dehydrator (~3 days) enables faster seed to seed cycling compared to the normal seed ripening process, which takes about 15 days, although it comes with a loss of grain weight.

Speed breeding opens the door to amazing possibilities

The article states that development under speed breeding was normal although accelerated, and the harvested seeds from speed-bred plants were completely viable.  Additionally, seed production (g per plant) was also similar between speed-breeding and control conditions in canola and chickpea. Hence, this method shows a great potential to accelerate cereal research and cultivar improvement when combined with modern breeding technologies.

One minute to compare Wheat growing under greenhouse conditions and Speed Breeding conditions.

Accelerated plant growth and development under speed breeding (left) compared to control conditions(right). Canola (B. napus cv. Bravo), pictured at 50 days post-sowing.

The publication demonstrates that speed breeding in fully enclosed, controlled-environment growth chambers can accelerate plant development for research purposes, including phenotyping of adult plant traits, mutant studies and transformation. 

UQ scientists, in partnership with Dow AgroSciences, have used the technique to develop the new ‘DS Faraday’ wheat variety due for release to industry in 2018. “DS Faraday is a high protein, milling wheat with tolerance to pre-harvest sprouting,” Dr Hickey said. “We introduced genes for grain dormancy so it can better handle wet weather at harvest time – which has been a problem wheat scientists in Australia have been trying to solve for 40 years,” Dr Hickey said. “We’ve finally had a breakthrough in grain dormancy, and speed breeding really helped us to do it.”

Other uses of the speed breeding have been reported, such as Dr Lee Hickey and PhD candidate Adnan Riaz, from the Queensland Alliance for Agriculture and Food Innovation who would use it to study ancient wheat varieties. see full article here: http://www.abc.net.au/news/rural/2016-03-30/ancient-wheat-genes-key-to-future/7281866

Dr Hickey believes the sky is the limit for the new technology and he is now investigating the integration of speed breeding with other modern crop breeding technologies.

“It could also have some great applications in future vertical farming systems, and some horticultural crops,” Dr Hickey said. 

Editor's point of view

Published in Plant Nature on January 2nd 2018, we decided to broadcast this news since such Speed Breeding Techniques could be pretty useful for  our relations in vegetal research.

Every research department in Plant science is running after time, mainly breeders, and accelerating nursery growth may be an option to consider. Such processes need more evaluation, and the services and tools we provide help R&D departments plan such experiments and analyze every environmental condition under the angle of the team's research objectives.

Feel free to contact us to know more about these techniques: contact(at)doriane.com

Sources:

https://plantae.org/what-were-reading-january-12th-edition/

https://www.nature.com/articles/s41477-017-0083-8

http://www.abc.net.au/news/rural/2016-06-20/lee-hickey-in-his-speed-breeding-lab/7525898

http://www.australasianscience.com.au/article/issue-september-2016/russian-revolution-could-save-aussie-wheat.html

http://www.globallnews.com/2018/01/growing-plants-with-speed-breeding-could-be-the-key-to-feed-the-worlds-exploding-population/

http://www.abc.net.au/news/rural/2016-03-30/ancient-wheat-genes-key-to-future/7281866

Original video here : https://www.nature.com/articles/s41477-017-0083-8

Rent or buy the full article : https://www.nature.com/articles/s41477-017-0083-8.epdf