Stefano Meneghetti

Study of Intra-Varietal Genetic Variability in Grapevine Cultivars by PCR-Derived Molecular Markers and Correlations with the Geographic Origins

The genetic grapevine intravarietal variability will be analyzed by PCR-derived marker systems. In particular, the object of the investigation will be the clonal variations of Malvasia nera di Brindisi/Lecce, Negroamaro and Primitivo, also known as Zinfandel, which are three grapevine varieties cultivated in Apulia region (Italy). In order to assess varietal identity of the samples, 132 DNA tests were performed by amplifying 16 SSR loci. The study of the intravarietal variability was performed using AFLPs, SAMPLs, ISSRs, and M-AFLPs. The application of the above-mentioned techniques allowed both to discriminate all genotypes of the three cultivars and to distinguish the accessions of each cultivar sampled from different geographic cultivation areas. Furthermore, the study of biotypes cultivated in different geographical environments of Salento (i.e., Apulia region) allowed important correlations between molecular marker variability and phenotypic traits. These results are suggesting both to focus our attention on the effects of the environment on the genotype and to consider, as a practical consequence, the importance of preserving autochthon grapevine biotypes found in different areas to truly preserve the richness of the germplasm. Thus, more accurate DNA studies give new information that can be extremely useful to the vine nurseries for the correct choice (i.e., supported by more accurate intravarietal variability analysis) of the grape multiplication materials.

A strategy to investigate the intravarietal genetic variability in Vitis vinifera L. for clones and biotypes identification and to correlate molecular profiles with morphological traits or geographic origins.

Grapevine is the most economically important and widely cultivated fruit crop in the world. Molecular markers have been used on Vitis vinifera to distinguish among both varieties and clones. Microsatellites are used to fingerprint varieties and several other techniques, reported in many papers, are used to analyze the differences among clones, but it is not available in the literature as a well defined strategy to screen a large number of Vitis cultivars. In fact, it is often necessary to use different techniques to investigate the genetic variability in different grapevine varieties and a proposed technique is used to study a cultivar, which is often not suitable for either the study of another cultivar or compare the genetic relationship among various cultivars. We describe here a strategy used for the analysis of several grapevine cultivars to describe a universal method to obtain DNA polymorphisms of Vitis vinifera genotypes from the same cultivar by using amplified fragment length polymorphism (AFLP), selective amplification of microsatellite polymorphic loci (SAMPL), microsatellites AFLP (M-AFLP), and ISSR molecular markers. The strategy here adopted permitted both to identify different biotypes (i.e., Primitivo), accessions (i.e., Garnacha tinta), and clones (i.e., Callet, Manto Negro, Moll) among the variability of same variety and to correlate the genetic differences to their geographical origins (i.e., Garnacha tinta; Malvasia nera di Brindisi/Lecce) or morphological traits (i.e., Malvasia of Candia). Here is also described the application of the protocol that allows to highlight the genetic variability accumulated during centuries of cultivations and selections of the same variety in different environments by vine growers.

Inter- and intra-varietal genetic variability in Malvasia cultivars.

The DNA molecular analyses together with ampelography, ampelometry, and biochemistry are essential for grapevine identification and investigation of genetic differences among the Vitis vinifera L. cultivars and clones. Ten Malvasia cultivars (i.e., Istrian Malvasia; M. delle Lipari; M. bianca di Candia; M. di Candia Aromatica; M. del Lazio; M. bianca lunga, also known as Malvasia del Chianti; M. nera di Brindisi/Lecce; M. di Casorzo; M. di Schierano, and M. nera di Bolzano) were analyzed using molecular approaches to study the genetic inter-varietal variability. Thirty Istrian Malvasia genotypes (i.e., 8 Italian clones, such as ISV 1, ISV F6, VCR 4, VCR 113, VCR 114, VCR 115, ERSA 120, ERSA 121, and 22 autochthonous grapevine accessions grown in Istrian Peninsula, Croatia) were investigated to evaluate the morphological and genetic intra-varietal variability. DNA analysis allowed discrimination of all Malvasia genotypes at molecular level using AFLP, SAMPL, and M-AFLP markers. Italian clones and autochthonous Croatian accessions of Istrian Malvasia were grouped according to their different geographic origins. These results showed the great genetic variability of Malvasia genotypes suggesting the need for the preservation of autochthonous grapevine biotypes found on different areas to approve the correct choice and selection of the grape multiplication materials.

Inter- and Intra-Varietal Genetic Variability in Vitis vinifera L.

Grapevine (Vitis vinifera L.) is the most economically important and widely cultivated fruit crop in the world and it is one of the oldest crops and the only Mediterranean representative of the Vitis genus (Clarke, 2001; Mullins, 1992; Galet, 2000). Its domestication produced culti‐ vars suited to a wide diversity of climates and tastes (Levadoux, 1956; Royo, 1997). In effect this genus shows a wide morphological and genetic variability that is causing confusions and ambiguity for biotypes and clones identification, in particular considering varieties that are widely distributed and cultivated for centuries (Tessier, 1999). Ampelography, ampel‐ ometry, and biochemical traits analysis have been traditionally employed to identify the dif‐ ferent biotypes in viticulture (Galet, 1979; Calo & Costacurta, 2004). However, these analyses are based on phenotypic characteristics which can be affected by environmental conditions (Meneghetti, 2011).

Genetic Variability and Geographic Typicality of Italian Former Prosecco Grape Variety Using PCR-Derived Molecular Markers

This study uses PCR-derived marker systems to investigate the extent and distribution of genetic variability of 80 Italian Prosecco accessions coming from Prosecco DOC area (north-east area of Italy). The studied samples include genotypes from Veneto and Friuli Venezia Giulia region. In order to verify the varietal identity of the samples, analyses based on 22 SSR loci were performed, and two grape varieties were found: Prosecco tondo and Prosecco lungo. In addition to microsatellite analysis, intra-varietal variability study was performed using AFLP, SAMPL, ISSR, and M-AFLP molecular markers. This molecular approach could discriminate different Prosecco tondo accessions coming from Treviso hills, from Veneto plain, from Friuli Venezia Giulia region, and from Padua hills (Serprina samples). As concerning Prosecco lungo variety, it was possible to discriminate molecularly the accessions from Veneto region and those from Friuli Venezia Giulia region. The molecular analysis allowed a distinction of the Prosecco genotypes on the basis of their geographic origins with plant-specific markers able to differentiate all Prosecco accessions. In this paper, the studied grape variety is termed Prosecco and not Glera (which is the present name) because the sampled vineyards were established many years ago when the name of the variety was Prosecco.