Genotyping of grapevine and rootstock cultivars using microsatellite markers

Sixty-six grapevine and rootstock cultivars from an Austrian germplasm collection were genotyped using the following 10 microsatellite loci: VVS1, VVS2, VVS3, VVS4 (THOMAS and SCOTT 1993), VVS29 (THOMAS, pers. comm.), VVMD5, VVMD7 (BOWERS et al. 1996), VVMD28, VVMD32 and VVMD36 (BOWERS and MEREDITH, pers, comm.). All cultivars except those which are thought to be closely related (e.g. Portugieser blau and Portugieser grun) provided unique allelic profiles. A phenogram based on pairwise similarity values revealed the separation of rootstock cultivars from the Vitis vinifera varieties. The probability for the presence of null alleles was estimated from heterozygote deficiencies and null alleles were statistically excluded at 9 of the 10 loci. In order to demonstrate the distinctive power of the microsatellite markers investigated, gene diversity (GD) values were calculated. For both grapevine and rootstock cultivars we estimated a GD range from 0.70 to 0.91, while GD values for grapevines only range from 0.52 to 0.87 and values for rootstocks from 0.29 to 0.86.