Whilst market demand for berries is increasing, gene erosion over the 70 years has meant that today’s cultivars are lacking in certain characteristics, according to Bruno Mezzetti, coordinator of the Horizon 2020 BreedingValue project.
“Several studies carried out on different crops have demonstrated that we have lost what we call allelic diversity; we have lost important genes. So the most advanced cultivars might look more ‘perfect’, but in reality they lack some characteristics,” Mezzetti told this publication.
He said the BreedValue project had been established to address this situation by recovering some lost genetic resources, with the ultimate aim of commercialising new high yielding, climate-resistant, high quality varieties.
“The aim is to establish a breeding programme between old germoplas and modern germoplas and generate new pre-breeding material - so new genetic resources that combine commercial and traditional traits that are important for the development of new cultivars,” he explained.
Smart screening tools
He was keen to emphasise that the methods employed do not involve gene editing or genetic modification but rather the use of advanced tools for high-throughput screening. “It is about genotyping and phenotyping the genetic material, through the application of marker assisted selection or new advanced genomic selection tools that help to predict the value of genetic resources in terms of delivering these important traits.”
For example, a new genomic selection tool developed during the project has been instrumental in predicting resistance to disease, according to Mezzetti.
“Powdery mildew caused by podosphaera aphanis is a major issue affecting fruit production. We have validated a genomic selection tool that, used in combination with the GWAS [Genome Wide Association Studies] approach, is a promising tool for predicting the resistance of genetic material to this disease,” he said.
He added that near-infrared spectroscopy is a promising tool for performing phenotyping without destroying the sample; 3D imaging and architectural phenotyping are valuable for predicting the yielding capacity of a plant; and metabolomics can help to identify the presence of compounds that contribute to nutritional and sensorial quality.
“It is about finding berry germplasm that has superior sweetness, more potent volatile compounds that are responsible for aroma, or an increased level of vitamin C, folates or other important biotic compounds, for example,” said Mezzetti.
Life cycle analysis tests sustainability attributes
In addition, the team is applying a new life cycle analysis tool.
“We are using life cycle analysis to assess the ecological benefit that new resilient cultivars can bring. This might be by reducing the use of herbicide or pesticide, or increasing yield, for example.”
The project started in 2021 with the identification and characterisation of all available genetic material for strawberries, blueberries and raspberries. This preliminary work demonstrated how different the old (pre 1960), modern (1960-2005) and new (2005 onwards) cultivars are in terms of their genetic variability.
“The new cultivars have a very different genetic background to the old cultivars we have tested. The idea is that we can recover several genes from the old cultivars that can improve the new cultivars, but we will need to keep most of the genetic background from the new cultivars as this is what, at the moment, is responsible for the traits that make these fruit competitive in the market,” said Mezzetti.
New varieties on the horizon
Using genomic tools, the project team has generated genetic resources or genotypes for new berry varieties, which it is testing through field trials and genomic, phenotyping and sensory analysis.
Since 2021, it has conducted a series of field trials in collaboration with 20 partners to test the pre-breeding material it has developed. The final field trial will be completed next month [June], and will be followed by analysis of the results, with the four-year project expected to complete by June 2025.
By then, Mezzetti said the project will have generated several patents - either for new varieties or new tools.
