M. Labra

Analysis of SSR and AFLP Markers to Detect Genetic Diversity Among Selected Clones of Grapevine (Vitis vinifera L.) cv. Keshmeshi

To assess the genetic differences between clones of grapevine (Vitis vinifera L.) cv. Keshmeshi, ten selected clones from a clonal selection programme were analysed by 23 Simple Sequence Repeats (SSR) and seven AFLP primer combinations. No intra-varietal differences between the clones could be detected by SSRs, whereas eight out of the 499 AFLP fragments generated by the seven primer combinations were polymorphic. The number of markers ranged from 44 (E34-M34) to 97 (E31-M32), with an average of 71.3 fragments per primer combination. Cluster analysis based on the AFLP data separated all the clones of Keshmeshi in two groups. The first group included nine white berry skin clones without any genetic differences, and the second group with only a red berry skin clone. AFLP could only distinguish the red berry clone of Keshmeshi from other white berry clones.

Genetic introgression of hybrid Rhododendron x intermedium Tausch is habitat mediated: Evidences from south-eastern Alps (Italy)

Hybridization between Rhododendron ferrugineum L. and R. hirsutum L. in south-eastern Alps was examined in order to (i) evaluate the breeding direction and the extent of backcrossing between hybrids and the parental species, (ii) define which processes facilitate speciation and maintain species identities and (iii) clarify the role of rock geochemistry in hybridization events. Individuals of three hybrid populations were analysed by morphological and molecular markers. The internal transcribed spacer and trnH–psbA distinguished the parental species and F1 hybrids while only the simple sequence repeat markers recognized genotype classes: F, H, F1, F2, BxF (backcross to R. ferrugineum) and BxH (backcross to R. hirsutum). Combining morphological and molecular data, we found that the tested populations had complex genetic structure: the F1 individuals produce F2 hybrids and backcross to parental species. Due to R. hirsutum phenology, most backcrossing events were with this parental species (asymmetric hybridization). Geochemical analyses indicate that alkaline soil conditions linked to calcareous dolomitic rocks promoted the genetic assimilation of R. hirsutum. In addition, R. x intermedium shows a higher edaphic adaptation than R. hirsutum as it can be found on a wide range of calcareous-dolomitic rocks as well as on weakly acidic soils of natural or anthropogenic origin.

Genetic diversity of wild grape (vitis vinifera ssp. sylvestris) populations in zagros forests as revealed by ssr markers

To reveal genetic diversity and provide information to conserve valuable grapevine germplasm, 63 wild accessions collected from five forest locations of the Zagros Mountains were genotyped by using 23 simple sequence repeats (SSR) loci. All primer pairs produced polymorphic banding patterns. In total, 182 alleles ranging from 3 (VVMD21) to 13 (VVMD5 and VVMD8) and with an average of 7.9 alleles/locus were amplified. Of these, 33 (18.13%) were specific to one of the wild grape populations collected from the five regions of the country. Analyses of molecular variance showed that 76.3 and 23.7% of the total molecular variation were contributed by within and between population variations, respectively. Cluster analyses assigned the accessions into three groups which were partially in agreement with their geographical distribution. However, some genotypes from one population were genetically closer to genotypes from other populations compared to accessions from the same population. Among the studied populations, high genetic variation and distinct gene stocks were observed in the Qasma rash-Sardasht population. This unique genetic structure of the Sardasht population indicates the need for a strong attempt to preserve wild grapevines as desirable genetic resources for breeding programs.