Coriander is one of the world’s most popular aromatic herbs, with a rich history dating back thousands of years. However, the genetics of this popular and versatile aromatic herb have have not received full attention.
It’s in salads. It’s in soup. It’s on top of chicken in a restaurant. It has been known to hide in sandwiches, or nestle on the top of a curry.
Coriander is one of the world’s most popular aromatic herbs, with a rich history dating back thousands of years. It has been so widely used for so long it’s difficult to establish exactly where it originates, although its story probably began in Western Asia or Southern Europe, where it still grows wild.
These days it is cultivated as a crop all over the world and is found in all kinds of cuisines. It can be used fresh (every part of the plant is edible) or as whole or ground seeds, and it lends itself equally well to sweet and savoury dishes.
However, despite its popularity and versatility, the genetics of this aromatic herb have not received full attention.
Traditionally, plant breeding involves crossing plants, growing the offspring to maturity, measuring desired traits, and selecting parents for the next generation.This gathers desirable alleles while keeping the background of the cultivar.
While this approach does improve performance, it’s slow. It usually takes more than a decade to bring a new commercial variety to market.
Breeders can speed things up with molecular breeding. Using marker-assisted selection (MAS) to find DNA markers associated with traits allows earlier - and potentially off-season - selection. Gene editing, which directly introduces desired traits, is even faster.
Both of these methods are now common in staple crops like wheat, but their potential benefits for herbs have been under-explored.
One of the key aspects is accelerating the breeding cycle by selecting parents using DNA markers rather than relying solely on phenotypic measurements.
Charles Dickinson, a PhD student at the Earlham Institute, is a CASE student with the Norwich Research Park Biosciences Doctoral Training Partnership (NRPDTP), meaning he collaborates with an industry partner on his PhD project.
He is working with seed specialist and plant breeder Elsoms Seeds to explore potential ways to accelerate breeding new coriander varieties.
“I was doing a Master’s in plant breeding at the John Innes Centre, and as part of that, I did a research project on wheat,” he says.
“Since I was already really interested in applying what I’d learned in a breeding context, when I saw the project with Elsoms it immediately appealed to me, especially because it had an industry angle.”
He is working with high-quality genome assemblies to improve understanding of biological variation in coriander.
“Ideally, by the end of my PhD we’ll have developed a panel of genetic markers that a breeding company like Elsoms can use in their programmes. We'd also like to have a clearer characterisation of coriander’s genetic diversity, which would help breeders identify untapped varieties or geographic regions.
“Along the way, we're also producing high-quality genomic resources - useful not just for breeders, but for the wider research community too.”
Charles Dickinson is a PhD student at the Earlham Institute on the Norwich Research Park Biosciences Doctoral Training Partnership (NRPDTP)
One key trait of interest to Charles is bolting - the plant’s transition from its vegetative stage to flowering. This change renders the leaves unusable and delaying it would improve crop yield. His goal is to delay bolting through molecular breeding.
“It’s not necessarily about doing something completely different, just doing it faster.” he says. “One of the key aspects is accelerating the breeding cycle by selecting parents using DNA markers rather than relying solely on phenotypic measurements. That’s a big time-saver."
So far, Charles has been working closely with the Earlham Institute’s Technical Genomics team to generate a high-quality reference genome using long-read sequencing technology and analyse biological variation using a diversity panel with many different lines of coriander.
This panel was grown in field trials and the lines with promising late-bolting traits were selected. Genome-wide association studies for bolting time identified several candidates for future gene editing.
“Understanding genetic diversity in coriander opens up new possibilities,” says Charles. “You can discover interesting varieties or traits from regions that haven’t yet been explored in breeding programs.”
Next steps for Charles include testing the candidate genes he has found in field trials and breeding populations to evaluate their effectiveness, refining trait mapping, and developing a general workflow for trait discovery in under-resourced crops.
