Blog Guinea grass reference genome to open new territories in forage breeding
A major step in the development of resilient guinea grass – a cornerstone in the Alliance of Bioversity International and CIAT’s tropical forages breeding program – has been reached with the release of the crop’s reference genome. It was sequenced by Corteva Agriscience using combined Pacbio HiFi, Bionano and Hi-C sequencing technologies and funded by Crops to End Hunger (CtEH). This reference genome will open a new era for breeding Guinea grass, a crucial tropical forage widely used for livestock feed in the tropics, and it will also benefit other breeding and research programs for genetically related species.
Guiness grass – a key forage for livestock
Guinea grass (Megathyrsus maximus), a perennial forage crop, ranks among the world’s largest sources of livestock feed, especially in tropical and subtropical regions. In Brazil alone, over 20 million hectares are dedicated to this resilient crop, which can thrive across diverse environmental conditions. This adaptability makes Guinea grass indispensable for livestock farmers in need of reliable forage.
But despite its global value, Guinea grass remains a semi-domesticated “orphan crop,” receiving limited investment. This creates an even greater need for public breeding initiatives to unlock its potential.
In this context and as part of its tropical forage crop breeding program, the Alliance focuses on developing improved Guinea grass varieties with enhanced resilience to challenges like drought, waterlogging, and low temperatures.
The power of a reference genome
The newly released reference genome provides a blueprint for the genetic makeup of Guinea grass, allowing researchers to identify and map genes linked to desirable traits. Previously, breeders faced significant challenges in identifying key genes due to the lack of a detailed genetic map. Now, with the genome sequence available, breeders can quickly locate genes associated with critical traits, enabling them to select the best candidates for breeding.
The reference genome functions much like a highly detailed map, showing the arrangement of DNA along chromosomes, complete with markers and alleles. This unprecedented level of detail in Guinea grass will empower The Alliance and breeders worldwide to make precise, data-driven decisions and expedite breeding cycles. This breakthrough will also benefit other breeding and research programs working on related species, as breeders often use reference genomes from closely related species when one is not yet available.
This genome sequencing initiative was made possible through the support of Corteva, leveraging their world-class plant genomics and reference assembly process, and funding from the Crops to End Hunger program, with financial backing from Germany through GIZ.
With the release of the reference genome, the next phase focuses on gene annotation—determining which genes are active under various conditions and pinpointing their exact locations within the genome. For gene annotation, the team is collaborating with the Earlham Institute, demonstrating that this methodology and CtEH-funded project are yielding further collaboration.
Gene annotation will enable marker-assisted selection and genomic selection, reducing the breeding cycle time and improving accuracy. The Alliance’s tropical forage breeding team uses advanced bioinformatics tools like CGIAR Breeding Analytics Pipeline, Bioflow, to analyze these genomic datasets and implement genomic selection.
