The "missing link" 'Blaue Zimmettraube' reveals that 'Blauer Portugieser' and 'Blaufränkisch' originated in Lower Styria

Parent offspring analysis already revealed genetic relationships for 'Blauer Portugieser' and 'Blaufränkisch', sharing at each locus one allele with 'Grüner Silvaner' and 'Weisser Heunisch', respectively. The missing second progenitor of 'Blauer Portugieser' and 'Blaufränkisch' is a recently rediscovered black grapevine, called 'Blaue Zimmettraube'. It was found in the largest German wine growing area Rheinhessen. The same cultivar was detected as a single vine in Friuli, Italy and named Sbulzìna. The 'Blaue Zimmettraube', bearing female flowers, and thus the female parent in the crosses, was cultivated in the 19th century in Lower Styria together with 'Grüner Silvaner' and 'Weisser Heunisch'. Because the 'Blaue Zimmettraube' did not exist in Austria and red wine production was fairly rare in that country before 1800, it is suspected that the cradle of 'Blauer Portugieser' and 'Blaufränkisch' is in Lower Styria. Furthermore, according to chlorotype analysis, it turned out that 'Blauer Gänsfüsser' is the male parent of 'Blaue Zimmettraube' and thus the 'Blaue Zimmettraube' represents a veritable "missing link". To prove the genetic relationships the nine GrapeGen06-markers and additional forty microsatellite markers were applied. Likelihood analysis with allele frequencies of 22 SSR-markers from 772 cultivars revealed a very high degree of probability that the proposed parents are consistent, due to rare alleles inherited from 'Blaue Zimmettraube'. To investigate on the geographical origin of 'Blauer Portugieser' and 'Blaufränkisch' historical Austrian and Styrian references were consulted.