Using SCC8, SCF27 and VMC7f2 markers in grapevine breeding for seedlessness via marker assisted selection.

We used molecular markers associated with seedlessness in grapes, namely SCC8, SCF27 and VMC7f2, to improve the efficiency of seedless grapevine breeding via marker assisted selection (MAS). DNA from 372 F1 hybrid progeny from the cross between seeded "Alphonse Lavallée" and seedless "Sultani" was amplified by PCR using three markers. After digestion of SCC8 marker amplification products by restriction enzyme BgIII, 40 individuals showed homozygous SCC8+/SCC8+ alleles at the seed development inhibitor (SdI) locus. DNA from 80 of the progeny amplified with the SCF27 marker produced bands; 174 individuals had 198-bp alleles of the VMC7f2 marker associated with seedlessness. In the second year, based on MAS, 183 F1 hybrids were designated as seedless grapevine candidates because they were positive for a minimum of one marker. Twenty individuals were selected as genetic resources for future studies on seedless grapevine breeding because they carried alleles for the three markers associated with seedlessness. The VMC7f2 SSR marker was identified as the marker most associated with seedlessness.

Amplified fragment length polymorphism analysis of grapevine rootstock genotypes in Turkey.

Amplified fragment length polymorphism (AFLP) technique was used to assess genetic relationships among 20 grapevine rootstocks in Turkey. Discrimination of the rootstocks with 10 primer combinations yielded 1366 bands on AFLP gels; 65% of them were polymorphic. The rootstocks revealed two main clusters; one of them comprised two (Malégue and Harmony) and the other 18 genotypes. The Ber x Rip hybrids Cosmo 2 and Cosmo 10 formed a group with a high internal similarity ratio (0.909); they also formed a group with other Ber x Rip hybrids, 5C, 8B, SO4, and 420A Mgt, with a similarity ratio higher than 0.690 (subcluster II). Rootstock 5BB was placed in another subcluster (subcluster III). Among five Ber x Rup rootstocks, 110R-99R (0.853) and 1103P-140Ru (0.837), which were located in different subclusters, formed a dual group, as expected. Rootstock 779P, which had almost 0.800 similarity with the dual group of 110R-99R, formed another group. The 44-53 Malégue and Harmony rootstocks formed a group with the lowest similarity ratio (0.668) (subcluster I) and 41B-Fercal formed another dual group with a high similarity ratio (0.813). The distinction capacity of single- and double-EcoRI-MseI primers was evaluated; primers AC/CTA, TC/CAC, AG/CTC, and AG/CAG discriminated the 20 rootstocks, with a similarity value below 0.910. The best primers for discrimination of rootstock varieties were AG/CAG and AG/CTC, while the primers TC/CAC and AC/CTA could also be useful for clonal discrimination of genotypes.

Multiple origins of cultivated grapevine (Vitis vinifera L. ssp. sativa) based on chloroplast DNA polymorphisms.

The domestication of the Eurasian grape (Vitis vinifera ssp. sativa) from its wild ancestor (Vitis vinifera ssp. sylvestris) has long been claimed to have occurred in Transcaucasia where its greatest genetic diversity is found and where very early archaeological evidence, including grape pips and artefacts of a 'wine culture', have been excavated. Whether from Transcaucasia or the nearby Taurus or Zagros Mountains, it is hypothesized that this wine culture spread southwards and eventually westwards around the Mediterranean basin, together with the transplantation of cultivated grape cuttings. However, the existence of morphological differentiation between cultivars from eastern and western ends of the modern distribution of the Eurasian grape suggests the existence of different genetic contribution from local sylvestris populations or multilocal selection and domestication of sylvestris genotypes. To tackle this issue, we analysed chlorotype variation and distribution in 1201 samples of sylvestris and sativa genotypes from the whole area of the species' distribution and studied their genetic relationships. The results suggest the existence of at least two important origins for the cultivated germplasm, one in the Near East and another in the western Mediterranean region, the latter of which gave rise to many of the current Western European cultivars. Indeed, over 70% of the Iberian Peninsula cultivars display chlorotypes that are only compatible with their having derived from western sylvestris populations.