Stefano Raimondi

Genetic Characterization of Grape Cultivars from Apulia (Southern Italy) and Synonymies in Other Mediterranean Regions

Forty-five grape accessions, traditional and historically mentioned in Apulia (southeastern Italy), were genotyped at 13 microsatellite (SSR) markers and observed for their morphological features with the aim of characterizing and identifying the local grape diversity relevant for economic or historical significance and for endangered germplasm conservation. Twelve of the 45 accessions examined were found to be synonyms or somatic mutants, leaving 33 distinct genotypes. Attempts were then made to verify the true identities of the accessions investigated and to determine their appropriate denominations. This entailed comparing them with published allelic profiles and morphological features of cultivars from Apulia and from surrounding areas linked historically to the region. While confirming the identity of the major Apulian cultivars, further matches with varieties from other Mediterranean regions were revealed. Approximately half of the Apulian cultivars investigated were found to have a foreign counterpart mainly along the Adriatic Sea (Croatia), in Greece, or in other southern Italian regions. The new synonymies found with cultivars traditional to other areas shed light on the migration of cultivars following the settlement of colonies and the historical establishment of Mediterranean trade routes.

The key role of “Moscato bianco” and “Malvasia aromatica di Parma” in the parentage of traditional aromatic grape varieties

A great number of flavored grape varieties, of significant oenological potential, are traditionally cultivated in north-western Italy, besides the renowned “Moscato bianco” (syn. “Muscat à petits grains blancs”). Understanding their origin, besides its historical and scientific interest, would help to increase market appeal and consequently facilitate the commercial exploitation of these products. Twenty-four aromatic genotypes were investigated for their identity, kinship relations, and genetic origins through molecular markers (SSR and SNPs) supported by plant morphology and historical information. Flavored grape genotypes from other regions, possible ancestors, and reference cultivars of known pedigree were also included in the analysis. Kinship analysis used a likelihood-based approach (IBS, IBD, relatedness coefficients, and likelihood ratios) to achieve strong statistical support. The analyses revealed two possible leading genitors, in turn closely related by a parent/offspring relationship: “Moscato bianco” and “Malvasia aromatica di Parma,” a female grape cultivar that is today almost extinct. The outlined molecular and statistical approach could be applied for the investigation on the origin of ancient traditional cultivars of other vegetative propagated species.

Whole-genome sequencing and SNV genotyping of ‘Nebbiolo’ ( Vitis vinifera L.) clones

Abstract‘Nebbiolo’ (Vitis vinifera) is among the most ancient and prestigious wine grape varieties characterised by a wide genetic variability exhibited by a high number of clones (vegetatively propagated lines of selected mother plants). However, limited information is available for this cultivar at the molecular and genomic levels. The whole-genomes of three ‘Nebbiolo’ clones (CVT 71, CVT 185 and CVT 423) were re-sequenced and a de novo transcriptome assembly was produced. Important remarks about the genetic peculiarities of ‘Nebbiolo’ and its intra-varietal variability useful for clonal identification were reported. In particular, several varietal transcripts identified for the first time in ‘Nebbiolo’ were disease resistance genes and single-nucleotide variants (SNVs) identified in ‘Nebbiolo’, but not in other cultivars, were associated with genes involved in the stress response. Ten newly discovered SNVs were successfully employed to identify some periclinal chimeras and to classify 98 ‘Nebbiolo’ clones in seven main genotypes, which resulted to be linked to the geographical origin of accessions. In addition, for the first time it was possible to discriminate some ‘Nebbiolo’ clones from the others.