Old for new, using ancient genetic variation to supercharge wheat
A global, collaborative effort led by the Earlham Institute, UK and CIMMYT, Mexico sheds light on the genetic basis of biomass accumulation and efficiency in use of light, both of which are bottlenecks in yield improvement in wheat.
Wheat is responsible for half of global calories consumed either directly or as animal feed and we need to make a lot more of it in the coming decades. Now, an important paper marks a step change in how breeders might approach wheat breeding using previously untapped sources of variation to increase yields to meet demand.
The recent paper, “Elucidating the genetic basis of biomass accumulation and radiation use efficiency in spring wheat and its role in yield potential”, first-authored by Dr Ryan Joynson of EI’s Anthony Hall Group and Dr Gemma Molero of Matthew Reynold’s team at CIMMYT, presents a valuable step forward for researchers interested in increasing wheat yield potential: a crucial task if we are to sustainably feed the planet.
The research, funded through IWYP (International Wheat Yield Partnership) shines light on the role of radiation use efficiency (RUE, how sunlight is converted into plant mass) in increasing the yield potential of wheat: how we can increase plant biomass without sacrificing grain yield - a major challenge.
This research highlights:
- Identification of genomic regions affecting RUE and biomass accumulation in spring wheat
- How increases in RUE can be achieved through strategic integration of “exotic” wheat into breeding programmes
- Identification of common genomic regions affecting yield, biomass and radiation use efficiency
- Enrichment of genes related with photoprotection in genomic regions associated with RUE at various growth stages
- Identification of untapped variation in wheat that can be harnessed and used by scientists and breeders
Dr Ryan Joynson, co-first author on the paper, said, “It’s really gratifying to use my computational skills in such an applied project and to see this research being incorporated into important international breeding programmes.”
Thanks to Norman Borlaug’s green revolution, led from CIMMYT, the development and improvement of dwarf varieties of wheat have led to a drastic increase in wheat yields over the better half of the 21st century. Yet, this consistent increase has wavered in recent years.
Continually increasing wheat yields is challenging, increasingly so when we must more-than-double them if we are to sustainably feed 10 billion people by 2050, half of whom will rely on wheat as a staple for bread, noodles and more. At current rates, we are predicted to only get to 38% increased wheat yields by 2050, which would mean a significant shortfall.
The challenge is the well-known trade-off between things such as grain weight/number and biomass. How do we reduce the leafy portion of a plant, or the underground portion, enough to boost harvestable product such that other aspects, including radiation use efficiency (hence photosynthesis) and nutrient uptake, are not disrupted or diminished?
Alternatively, how do we increase biomass and the relative efficiency of photosynthesis, without reducing the harvestable portion of the crop - the grain?
Photosynthesis itself is pretty inefficient, so it must be possible to find a happy medium between less biomass, more grain, and more efficient photosynthesis - so where better to start than to identify genes and genetic regions underpinning all of these traits in elite lines of wheat?
By growing 150 types of wheat, then mapping the differences in growth to differences at the genetic level, it was possible to understand areas of commonality in desired traits for crop improvement.
A new resource for breeders
Through analysing new variation in elite wheat lines, while looking for the genetic markers underpinning and linking traits such as radiation use efficiency, biomass, yield, grain number, grain weight, etc., the researchers have provided an important resource for scientists and breeders to exploit.
Namely, markers for use in marker-assisted breeding, that will help increase desired outcomes - such as biomass, thousand grain weight and radiation use efficiency - while avoiding the trade-off between grain weight and grain number, or between biomass and harvest index.
The study represents the completion of two years of work looking at 150 wheat varieties, using a genome-wide association study to analyse 31 different traits. Among the genetic regions identified, several were found in specific regions common to grain yield, biomass and radiation use efficiency.
Another important aspect of the work was the investigation of the effect of sources of new variation into elite lines of wheat. Comparing elite wheat varieties alongside “exotic” lines such as landraces and synthetic wheat, the researchers pinpointed areas of interest for future breeding programmes, i.e. where we can introduce more variation into our best wheat varieties for desired outcomes.
Notes to editors.
Notes to editors
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About Earlham Institute
The Earlham Institute (EI) is a world-leading research Institute focusing on the development of genomics and computational biology. EI is based within the Norwich Research Park and is one of eight institutes that receive strategic funding from Biotechnology and Biological Science Research Council (BBSRC) - £5.43m in 2017/18 - as well as support from other research funders. EI operates a National Capability to promote the application of genomics and bioinformatics to advance bioscience research and innovation.
EI offers a state of the art DNA sequencing facility, unique by its operation of multiple complementary technologies for data generation. The Institute is a UK hub for innovative bioinformatics through research, analysis and interpretation of multiple, complex data sets. It hosts one of the largest computing hardware facilities dedicated to life science research in Europe. It is also actively involved in developing novel platforms to provide access to computational tools and processing capacity for multiple academic and industrial users and promoting applications of computational Bioscience. Additionally, the Institute offers a training programme through courses and workshops, and an outreach programme targeting key stakeholders, and wider public audiences through dialogue and science communication activities.