An international research project, involving the University of Adelaide, has discovered the gene responsible for a rare form of wheat that grows three ovaries per flower instead of one.
Researchers say this could help wheat farmers increase their grain yield and improve the efficiency of hybrid seed production.
The special trait of growing three ovaries per flower was discovered in a spontaneously occurring mutant of common bread wheat, but the genetic changes that led to the new trait were not clear.
A team led by groups at the University of Maryland and University of Adelaide, and including researchers from the United States, Australia, Canada, the United Kingdom and New Zealand, created a highly detailed map of the multi-ovary wheat’s DNA and compared it to regular wheat.
They found a complex genome rearrangement in the multi-ovary wheat was associated with the ‘switching on’ of a normally dormant WUSCHEL-D1 (WUS-D1) gene, and when active early in flower development, the gene enlarged the flower-building tissues, enabling them to produce extra female reproductive organs.
“Pinpointing the genetic basis of this trait offers a path for breeders to incorporate it into new wheat varieties, potentially increasing the number of grains per spike and overall yield,” said co-senior author Vijay Tiwari, Associate Professor of Plant Sciences at the University of Maryland.
“By employing a gene editing toolkit, we can now focus on further improving this trait for enhancing wheat yield and improving breeding technologies to develop cost-effective hybrid wheat.”
This breakthrough emerged from an international collaboration that brought together experts from multiple disciplines to unravel the complex genetic and developmental basis of this wheat mutant.
The study, published in PNAS, also reveals new insights into the biology of yield-related traits in wheat.
“Identifying WUS-D1 as a regulator of ovary formation in wheat reveals new opportunities to improve yield by increasing the number of cells in the developing floral structures,” University of Adelaide Associate Professor Scott Boden said.
“These findings also demonstrate exciting links between floral development in wheat and other major cereals, such as maize, rice and barley.”
The research team hopes their finding could lead to new wheat varieties that grow more grains per plant, contributing to the huge increases in food supply required at the global scale for the world’s growing population.
