Genomes of Alopecurus Grasses Shed Light on Weed Resistance

The genomes of two new Alopecurus grasses, blackgrass and orange/shortawn foxtail, have been sequenced by researchers from the Rothamsted Research, Earlham Institute, and the European Reference Genome Atlas (ERGA) initiative, revealing how similar weeds can dominate wheat fields that are geographically separated by over 5,000 miles.

Both blackgrass (Alopecurus myosuroides) and orange/shortawn foxtail (Alopecurus aequalis) are native to many regions across the Northern Hemisphere. However, blackgrass is a predominant agricultural weed in Western European winter wheat and barley, whereas orange foxtail has emerged as the dominant agricultural weed for similar crops in parts of China and Japan. Both weeds grow in grass crops and frequently out-compete cereal crops. Changes in cropping practices have not been effective in controlling the weeds, and both have evolved resistance to multiple herbicides.

The orange foxtail genome at 2.83 Gb is smaller than the blackgrass genome (3.572 Gb) and contained just over 33,750 protein-coding genes. The genome is assembled into a total of seven chromosome-level scaffolds, and most are complete with telomere sequences on one or both ends.

“When we compared the orange foxtail and blackgrass genomes to barley - a crop they grow in - we were surprised to find that the orange foxtail genome structure is more like barley than blackgrass. Such genomic rearrangements highlight areas of functional conservation or divergence that drive adaptations to specific environments or ecological niches,” said Rothamsted researcher Dr. Dana MacGregor, last author on the A. aequalis genome and co-author for the A. myosuroides genome.

For more details, read the news release in Rothamsted Research News.