Roots are the main channel for water and nutrient uptake in plants. Optimization of root architecture provides a viable strategy to improve nutrient and water uptake efficiency and maintain crop productivity under water-limiting and nutrient-poor conditions. We know little, however, about the genetic control of root development in wheat, a crop supplying 20% of global calorie and protein intake. To improve our understanding of the genetic control of seminal root development in wheat, we conducted a high-throughput screen for variation in seminal root number using an exome-sequenced mutant population derived from the hexaploid wheat cultivar Cadenza. The screen identified seven independent mutants with homozygous and stably altered seminal root number phenotypes. One mutant, Cadenza0900, displays a recessive extra seminal root number phenotype, while six mutants (Cadenza0062, Cadenza0369, Cadenza0393, Cadenza0465, Cadenza0818 and Cadenza1273) show lower seminal root number phenotypes most likely originating from defects in the formation and activation of seminal root primordia. Segregation analysis in F2 populations suggest that the phenotype of Cadenza0900 is controlled by multiple loci whereas the Cadenza0062 phenotype fits a 3:1 mutant:wild-type segregation ratio characteristic of dominant single gene action. This work highlights the potential to use the sequenced wheat mutant population as a forward genetic resource to uncover novel variation in agronomic traits, such as seminal root architecture.
Bibliographical noteFunding Information:
We would like to thank Dr Jonathan Atkinson, Prof Malcolm Bennett, Chloe Riviere and Guiditta Giordani for technical advice and assistance in the setting up the high-throughput 2D root screen and Andrew Davis for help with root imaging. This research is supported by the UK Biotechnology and Biological Sciences Research Council (BBSRC) Designing Future Wheat program (BB/ P016855/1), a Royal Society FLAIR award (FLR\R1\1918500) to OS, a BBSRC DTP award to RK, the Chief Scientist of the Israel Ministry of Agriculture and Rural Development grant (#12-01-0005), and the U.S. Agency for International Development Middle East Research and Cooperation grant (# M34-037).
Copyright © 2019 Shorinola et al.
- Forward Genetics