Science1 publisher2 min readPublished
Genome study maps camelina's wild relatives as a diversity source for breeders of the oilseed
GIFS and AAFC researchers have mapped a fourth Camelina subgenome, work they say makes wild relatives' diversity easier to breed into the oilseed. Better yield or oil from that diversity has not yet been shown.
The Scientist · Science desk
What happened
- Lead author Raju Chaudhary said camelina has very low genetic diversity despite new interest in developing it as a modern crop, and that the team set out to increase it.
- Andrew Sharpe of GIFS named food, animal feed and potential biofuel as the crop's three main agricultural product opportunities.
- The account lists yield stability, oil quality, stress tolerance and adaptation to Western Canadian production systems as traits the added diversity could support.
- The project grew out of Chaudhary's PhD at USask with Isobel Parkin of AAFC and builds on her earlier work on camelina genome evolution and diversity.
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Why it matters
- constraint Growers and processors hoping for steadier camelina yields or better oil cannot plan on them from this paper, because the step from gene expression to field traits is still untested.
- capability Breeders can now plan wild-by-crop crosses against known genome structures for the donor species, the step Sharpe says makes the transfer easier.
- precedent Sharpe pitches the approach at crops with limited genetic resources, so camelina's results will be a test case for other crops that get less attention than wheat and canola.
The new science is in the paper's title: "A fourth subgenome of the Camelina genus reveals gene dominance is influenced by chromosomal proximity" [3]. Raju Chaudhary, a GIFS research associate and one of the lead authors [2], did not claim the crop's history is settled. "The evolution of this crop is interesting, as well as a mystery," he said [6].
The second half of that title is the part with a path to breeding. The team worked out how the structure of the camelina genome affects gene expression. The account calls this a step toward understanding how specific traits can be selected and improved [4]. "We have provided a broad picture of how the proximity of the chromosomes in the nucleus contributes to gene expression," Chaudhary said. "Exploring how these interactions influence important traits in the plant and how we can use that knowledge to improve the crop will be the next step." [5]
His second sentence sets the limit of the result. The study connects where chromosomes sit inside the nucleus to which genes are switched on. It does not yet connect either one to a trait a grower would see in the field. Chaudhary places that work in the future [5].
The case that breeders can use the wild species comes from Andrew Sharpe, a senior research scientist at GIFS who contributed to the paper [7]. "There are limited resources for breeders to use to generate new camelina varieties," he said. "With this knowledge, we have a pretty good idea about the structure of genomes for other wild camelina species, which have much more diversity in them, and it means it's now actually easier to transfer that diversity into crop camelina." [8] He did not put a figure on "much more diversity", and the published account does not say how many wild species or lines the team sequenced [8].
I think the claim holds in the narrow form Sharpe gives it. "Easier" is a statement about the cost of future crosses. Knowing the donor species' genome structure is a reasonable basis for that statement. Whether wild variation reaches a variety a farmer can buy depends on crosses and seasons of field testing that come after this paper. Sharpe called the output "foundational resources" for scientists and breeders [14].
He also argued the approach matters beyond this one crop. "This research can have really big implications for the applied side, like breeding, especially in crops which have more limited genetic resources," Sharpe said [10]. "A lot of effort has been spent on wheat and canola, of course, but not as much on these other crops." [11]
What to watch
- The first reported crosses between wild Camelina species and crop camelina, and whether the wild material carries over without hurting yield.
- Follow-up work from Chaudhary's group tying the chromosome-proximity effect on gene expression to specific plant traits.
- Field data on yield stability or oil quality in Western Canadian systems from camelina lines with wild ancestry.