Molecular Ecology (2000) 9, 229–232 © 2000 Blackwell Science Ltd SHORT COMMUNICATION The use of random amplified polymorphic DNA (RAPD) markers to identify strawberry varieties: a forensic application L. CONGIU,* M. CHICCA,* R. CELLA,*† R. ROSSI* and G. BERNACCHIA* *Department of Biology, University of Ferrara, via L. Borsari 46, 44100 Ferrara, Italy, †Department of Genetics and Microbiology, University of Pavia, via Ferrata 1, 27100 Pavia, Italy Abstract The random amplified polymorphic DNA (RAPD) technique was applied to settle a law- suit involving unauthorized commercialization of a patented strawberry variety of high economical relevance (‘Marmolada’®). Because of economical involvements, the molecular approach was added to the more traditional morphological examination in a double-blind test. All plants belonging to the patented variety were unambiguously identified (13 plants among a total of 31 plants examined). The results were accepted as evidence in the court. This study confirms that the RAPD technique is especially suitable for identification of asexu- ally reproduced plant varieties for forensic or agricultural purposes. Keywords: cultivar identification, DNA extraction, forensic, patented variety, RAPD, strawberry Received 24 April 1999; revision received 24 July 1999; accepted 24 July 1999 Introduction The identification of different varieties of plants is a relevant issue especially when it concerns commercially valuable species such as fruits. Frequently, the varieties obtained through genetic selection for commercial purposes involving high economical interests are protected by inter- nationally registered trademarks. Thus, the unauthorized commercialization of patented varieties leads to lawsuits requiring careful technical investigations. These expertises are mainly based on morphological characters and often do not yield clear answers concerning the identification of the plant variety under scrutinization. The molecular approach has proved itself an increas- ingly valuable tool in the identification of plant varieties (Morell et al. 1995). Some of the commercially desirable ones, such as strawberries, are reproduced by micropro- pagation; therefore all individuals belonging to a given variety share an identical genome. The lack of intravariety genetic variability greatly simplifies the task of identifica- tion because any difference between two given individuals unambiguously indicates that they belong to different varieties. In this field one of the most successful tech- niques is random amplified polymorphic DNA (RAPD) (Welsh & McClelland 1990; Williams et al. 1990) which has two main advantages: it allows random sampling of markers over whole genomic DNA and does not require any previous information on the genome of the organism under investigation. Here we present the results of a forensic application of RAPD markers to clarify whether some strawberry plants had been unauthorizedly commercialized. The law- suit involved an Italian patented variety, ‘Marmolada’®, registered in 1984 by the Consorzio Italiano Vivaisti (CIV), S. Giuseppe di Comacchio (Ferrara, Italy). The case was brought against farmers suspected of having reproduced and commercialized without permission this cultivar, of relevant economical value because it is highly resistant to cold weather, and therefore suitable for continental areas and out-of-season production by hydroponic cultures. This cultivar also shows high productivity and low sens- itivity to grey mould (Botrytis cinerea Pers. 1822). About one million strawberry plants were sequestered in a farm under suspicion to belong, on a morphological basis, to the ‘Marmolada’® variety, although the farmers claimed differently. To settle the lawsuit, the court needed un- ambiguous evidence of their identification. The RAPD technique was chosen because it had been successfully Correspondence: L. Congiu. Fax: + 39 49 249761; E-mail: col@dns.unife.it