East Malling Research to Fingerprint UK National Fruit Collection

Scientists at EMR will use DNA markers called microsatellites, to produce individual profiles for each tree. This will help curators to verify the uniqueness of material in these collections. It will also assist in the identification of trees previously unnamed after traditional morphological comparisons. Detection of duplicates and incorrectly named accessions will enable streamlining of the UK's National Fruit Collection, help to reduce costs and allow duplicated plants to be replaced by other accessions.

EMR has already fingerprinted the first half of the 545 pears and 200 cherries of the National Fruit Collection. Two previously unknown pairs of identical pear accessions were identified as Vermont Beauty and Southworth, and Jean de Witte and Blickling, and scientists confirmed that another accession identified as Achan was in fact Autumn Bergamot. An unexpected finding was the discovery of a high level of triploid pears at 20%, compared to the 5-10% expected. This has implications for conventional breeding, for which triploid plants have limited use. Interestingly, of the first batch of 100 cherries fingerprinted, only 50% were found to be unique.

The collection is being verified using a set of reference microsatellite markers approved in collaboration with other international groups. The UK’s national collection will therefore be directly comparable with those from other countries.

On completion, examination of the diversity of material within the collection could help to detect significant gaps in varieties or groupings. In addition, through the application of more involved analyses, scientists could determine how distinct e.g. the perry, Asian and European (Pyrus) pears in the collection are from each other, or the extent to which apple and pear cultivars have captured the range of variation in wild relatives.

Emma-Jane Allen, Imperial College’s scientific curator of the collections said “Genetic fingerprinting of the apple and pears will allow a substantial increase in the efficiency of curating these collections. We also hope that the fingerprints will reveal information about the relationships between apple and pear varieties conserved in the National Fruit Collections.”