Allele-aware chromosome-level genome assembly and efficient transgene-free genome editing for the autotetraploid cultivated alfalfa
Researchers have assembled the genome of alfalfa and established a protocol for editing it with the CRISPR-Cas9 system, providing key resources for research into and molecular breeding of this important crop.
The complexity of the alfalfa genome coupled with the plant’s self-incompatibility has made it a difficult crop to breed.
To assemble its genome, a team led by researchers at Lanzhou University in China exploited a new sequencing approach known as consensus circular sequencing. Together with a method called chromosome conformation capture, this enabled them to generate a high-quality assembly that included the allelic variation throughout the genome.
The team then used this to guide the construction of a CRISPR-Cas9 system to knock down a specific target gene. As a proof-of-concept, they disabled the PDS gene and showed that the mutation was inherited in the following generation. These tools will be valuable in efforts to improve this important crop.
- Nature Communications 11, 2494 (2020). doi: 10.1038/s41467-020-16338-x