DNA fingerprinting was performed as described in Bergamini et al. (2013). Briefly, genomic DNA was extracted from young leaf tissue using Qiagen DNeasy Plant Mini Kit (Qiagen, Valencia, CA) on liquid nitrogen-frozen leaf samples, after homogenization by Qiagen Tissue Lyser (Qiagen, Valencia, CA), according to the manufacturer instruction protocol. Purified DNA was used as template in a PCR amplification for genotyping using 60 nuclear SSR loci ISV2, ISV3, ISV4, VVS2 (Thomas and Scott 1993), VVMD5, VVMD7, VVMD25, VVMD27, VVMD28, VVMD32 (Bowers et al. 1996, 1999b) VrZAG62, VrZAG79, VrZAG21, VrZAG112 (Sefc et al. 1999) and VMCNG4b9 (Vitis Microsatellite Consortium), VChr-1b, -2b, -3a, -4a, -5b, -5c, -6a, -7b, -8b, -9a, -10b, -11b, -12a, -13a, -15a, -16a, -17a, -18a, -19a (Cipriani et al. 2008) and VVI-b01, -b23, -b63, -b66, -b94, -f52, -h54, -i51, -m10, -m11, -m25, -n54, -n61, -n94, -o55, -p25b, -p37, -p77, -r09, -s21, -s58, -s63, -u04, -v37, -v61, -v69 (Merdinoglu et al. 2005). A set of chloroplast specific microsatellite loci primers was also employed: ccSSR-5, ccSSR-14, ccSSR-23 (Chung and Staub 2003), cpSSR10 (Weising and Gardner 1999), NTCP8 (Bryan et al. 1999). Chlorotypes definitions are defined following Arroyo-Garcia et al. (2006). The cycling profiles were as reported in Bergamini et al. (2013). PCR reactions were conducted in 10 μl volume containing 25 ng of genomic DNA, 5 pmol of each forward and reverse primer and 5 μl of QIAGEN Fast Cycling PCR Master Mix 2X. Three or more primer pairs were carefully combined to co-amplify in a single reaction and each forward primer was labeled with WellRED dyes, D2-PA (black), D3-PA (green) or D4-PA (blue), at the 5′end. Amplicons were analysed on a CEQ™ 8000 Series Genetic Analysis System, automatically sized using a CEQ DNA Size Standard Kit 400 (Beckman Coulter S.p.A., Milan, Italy), and then visually inspected and manually recorded.