Spain Maps the Olive Genome to Breed Better Trees

Spanish researchers say they have produced a genetic map of the olive and pinned down genes behind the fats, the antioxidants and the aroma compounds that end up in the oil, along with genes for tree vigor and early cropping. The work comes out of Oleagen, a three million euro project run from Andalusia that is now finishing. Here is what has been built, what it is for, and how long it takes to turn any of it into a tree you can plant.

What the project built

Oleagen is coordinated by the Genoma Espana foundation, the Andalusian institute for agricultural research and training, IFAPA, and Corporacion Tecnologica de Andalucia. The research team runs to 59 scientists in 12 groups, nine of them in Andalusia, at IFAPA’s Alameda del Obispo center in Cordoba, the Institute for Sustainable Agriculture, the Instituto de la Grasa of the Spanish research council and the universities of Cordoba, Malaga and Jaen.

Three things came out of it. A genetic map of the olive with markers that breeders can use. A database of genomic and agronomic information with a bioinformatics platform on top. And, the researchers say, the first proven method of genetically transforming an olive, which is the laboratory tool you need in order to test what a gene actually does.

• Genes involved in accumulating fatty acids in the fruit, which set the oil’s composition.
• Genes behind polyphenols, the antioxidants that make an oil bitter, pungent and stable.
• Genes behind the volatile compounds that give an oil its aroma.
• Genes for tree vigor, architecture and how soon a young tree starts to crop.

The material came from the world olive germplasm bank at Cordoba, which holds hundreds of cultivars collected from across the Mediterranean and beyond, and which is the real asset here. A map is only as good as the diversity you can read with it.

What it is for

The stated aim is commercial: varieties that make more oil, better oil or healthier oil, and trees that suit the way olives are increasingly grown. That last part is the one to watch. The list of traits includes small trees, fast entry into production and an architecture that suits dense hedgerow planting, because that is where new Spanish plantings are going.

Olive breeding is painfully slow. A seedling can take five to twelve years to fruit, so a conventional program spends a working lifetime on a couple of generations. Marker assisted selection changes that arithmetic: you screen seedlings as small plants for the markers you want and throw away most of them before they ever take up orchard space.

What it does not do

A genetic map is not a variety. Nothing from this project will be in a grove for years, and the traits that matter commercially are controlled by many genes at once, along with the soil, the water and the year. Genetic transformation, which is the part that makes headlines, is a research tool here rather than a product plan, and a transgenic olive would face a European regulatory wall that no one in this sector is in a hurry to walk into.

The honest summary is that Spain has built the instruments. Whether they produce a better bottle depends on what the industry asks the breeders for, and today it is mostly asking for yield per hectare and trees that fit a harvester.

Sources

• Olive Oil Times, Designing Better Olive Oil through Genetic Mapping
• Corporacion Tecnologica de Andalucia, Un proyecto pionero analiza el mapa genetico del olivo