First strawberry map to lead to better flavour?

The wild strawberry (Fragaria​) map built by researchers at East Malling Research (EMR) and the University of Reading in the UK should lead to greater efficiencies in strawberry breeding.

"It will provide a foundation for the development of a map for the genetically complex commercial strawberry (Fragaria x ananassa), ultimately achieved through the integration of molecular techniques like marker assisted selection,"​ report the scientists.

Strawberries are commonly used by food makers in a range of products, as a flavour for milk based yoghurts and drinks to the manufacture of confectionery items and pie and pastry fillings.

And good flavour in strawberry fruit is an attribute, gaining increasing importance in the production of strawberries. It is possible that the flavour of modern strawberry varieties has been sacrificed to an extent as a result of intensive production, and the tendency towards optimising yields, fruit shape and colour, and breeding resistance to pests and diseases.

So far 67 DNA markers and 23 genes controlling characteristics of potential commercial importance have been located on the wild strawberry map, that could provide a framework for the design of improved flavour profiles.

"The two species also differ widely in traits potentially important for strawberry breeding, for example, fruit size, runnering, everbearing, plant architecture and aromatic composition (flavour),"​ say the scientists.

Wild strawberry plants from a cross between Fragaria vesca​ (the woodland strawberry) and Fragaria nubicola​ (a wild Asian strawberry), provided a model system for the UK team to study inheritance.

Wild strawberry is diploid, plants that have two copies of every chromosome and the cultivated strawberry is octoploid, it has eight copies of every chromosome.

According to the researchers, their work has already been adopted as the reference map by strawberry research groups in Spain, France and the US, and could lead to the creation of a worldwide strawberry genetic research network.

The US is the world's leading producer of strawberries for both the fresh and frozen markets. Total production averaged over 800,000 tons from 1996 to 2002 with about 25 per cent of that going to the frozen market.

Spain is the second largest producing country with most of its production used by the fresh market with Poland coming in as third largest producer, although the second leading frozen strawberry producer.

Although Japan produces slightly more than 200,000 tons annually, but consumes almost all of its production in fresh form and imports additional supplies to fulfill its domestic demand.

Demand levels have dropped in recent years. The US government estimates that in 2002/03, fresh strawberry production for selected major producers was estimated at 1,800,652 metric tons, an increase of less than one per cent over the 2001/02 level.

Frozen strawberry production during the same time span dropped 6 per cent to 396,696 tons for the same countries.