Rootstock variety identification

Variety identification in grapevine grafting is not only important in the case of the scion, but also for the rootstock. The choice of rootstock variety can be decisive due to its compatibility with certain soil types and interactions with the graft.

Usually, grapevine varieties are identified by morphological characteristics such as leaf shape and size, as well as the type and density of hairs on the shoot tips and leaves, i.e. they require the presence of green tissue. Since rootstocks are traded as cuttings, their identification by morphological characteristics based on green tissue is naturally not possible. By extracting the genomic DNA of the variety sample to be analyzed and performing an RAPD reaction (randomly amplified polymorphic DNA) with this DNA as a template, this PCR-based random amplification of DNA fragments and their subsequent gel electrophoretic separation can be used to determine the variety present or to check for unintentional mixing of different batches. This is important, for example, for post-control cultivation within the framework of the “Rebenpflanzgutverordnung” (Vine Planting Material Ordinance), where samples of rootstocks are tested for their correct variety classification. For this purpose, DNA samples are isolated from cuttings from rootstock plantations and thus checked for identity and purity.