Development of stable RAPD markers for the identification of grapevine rootstocks and the analysis of genetic relationships

The use of the RAPD technique was investigated on a set of 30 grapevine (Vitis ssp.) rootstock cultivars. The DNA was extracted directly from woody canes using a CDAB technique. The screening of 21 decamer oligonucleotides allowed the selection of six primers used for the analysis. They revealed a high level of polymorphism among the rootstocks. Twenty bands, intense and easy to score, were chosen as markers. Identification of 23 out of the 30 rootstocks was obtained with only two primers (opP17 and opAO9). The addition of one primer (opA20) allowed the identification of the complete set of rootstocks. Based on simple matching coefficient calculated from RAPD data, a tree was generated. It clearly reflected the genetic relationships between the rootstocks. The stability of the markers was tested in very diverse conditions. The main factor of variability was the origin of the Tag polymerase. Given a preliminary screening step, RAPD markers proved to be very stable and useful for identification purpose since they are quick and easy to use.