Wheat provides 20% of the total calories and protein content for the world's population and is a staple for more than 2.5 billion people around the world. However, the production system for this grain is currently facing several challenges that demand immediate solutions. How can wheat productivity increase in order to feed a population that will reach 9 billion in 2050 and at the same time deal with limited farmland and the harsh effects of climate change? Not to mention the threat of pests, for which it is necessary to find sustainable means instead of using harmful products.
The importance of this grain in the world's diet makes the search for the solutions to these challenges a matter of great urgency. In recently published research in the journal Nature Genetics, an international scientific team, including University of Cordoba researcher Carlos Guzmán, looked into the validity of genomic selection to improve wheat on a genetic level in order to cope with these problems.
"We are talking about testing whether it is possible to use information available in the genome to predict how productive a variety of wheat will be, if it will be drought- or heat-resistant and what quality its grain will have," explains Guzmán, who participated in the study via his work as head of the Chemistry and Wheat Quality Laboratory at the International Maize and Wheat Improvement Center (abbreviated to CIMMYT in Spanish) in Mexico.
According to the researcher, "thanks to this study, it will be possible to speed up improvement programs in order to develop new varieties of wheat, with less field work and less lab work."
The main aim of the study was to verify how precise the predictions done with genomic selection were for each characteristic of wheat. The results were quite varied. "For instance, the level of prediction was very good to determine resistance to certain diseases and grain quality but results were lower when attempting to predict yield," explains Carlos Guzmán.
Another aim was to find out which chromosomal regions of the DNA are associated with a specific characteristic in order to identify which gene or gene group needs to be worked with to improve each characteristic. Moreover, the identified chromosome regions turned out to be consistent over several geographical areas, meaning these results could be applied to other wheat improvement programs.
Though research has already been done in this area, this research project has the widest scope that has been done to date, due to the extent of the wheat populations and the diverse environments used to measure certain characteristics, such as field performance. In this specific case, experimental trials in over ten countries were used. The wide range of these countries include Canada, Mexico, India, Morocco and Sudan, leading to more precise results.
"The next step will be to see how we can integrate the genomic selection tool into a real wheat improvement program such as the International Maize and Wheat Improvement Center," reveals Carlos Guzmán. This program is one of the most important ones in the world. It is estimated that over 50% of the varieties of wheat grown around the world originally came from, or partly from, the International Maize and Wheat Improvement Center.
This program seeks to obtain varieties of wheat that are more productive, more disease-resistant, more tolerant to climate change and that produce grains that make flour suitable for making a range of different products. This can be done by genetic crossing and improvement. In addition to increasing wheat production, research is also being done to improve its nutritional content, given that most people who have wheat as a staple in their diet get insufficient iron and zinc.
The next research projects will focus on improving genomic selection technology and finding new ways to predict yield. According to the researcher, "this tool will not do away with field testing but it will help reduce it, which will lower costs and save time."
Philomin Juliana, Jesse Poland, Julio Huerta-Espino, Sandesh Shrestha, José Crossa, Leonardo Crespo-Herrera, Fernando Henrique Toledo, Velu Govindan, Suchismita Mondal, Uttam Kumar, Sridhar Bhavani, Pawan K. Singh, Mandeep S. Randhawa, Xinyao He, Carlos Guzman, Susanne Dreisigacker, Matthew N. Rouse, Yue Jin, Paulino Pérez-Rodríguez, Osval A. Montesinos-López, Daljit Singh, Mohammad Mokhlesur Rahman, Felix Marza, Ravi Prakash Singh. Improving grain yield, stress resilience and quality of bread wheat using large-scale genomics. Nature Genetics. DOI: 10.6084/m9.figshare.8940257.v1