Genotype assessment of grape regenerants from floral explants

A molecular typing of regenerant vines based on co-dominant simple sequence repeat (SSR) markers was applied for checking recombination events during somatic embryogenesis from floral explants. Twenty-one samples of somatic embryos and plantlets from embryogenic callus of both anthers and ovaries of the V. vinifera cv. Chardonnay, the rootstock Kober 125 AA, and the accession V. rupestris du Lot were randomly chosen from a number of regenerant lines. The genotype at polymorphic VVS2, VVMD5, VVMD7, VVMD27, VrZAG62 and VrZAG79 loci was produced and compared with reference patterns. No recombination events were detected in the cells involved in the somatic embryogenesis induction of all the checked samples, since all of them generated the same SSR profile of the grape variety from which explants were isolated.

RAPD markers in wild and cultivated Vitis vinifera

Some Vitis vinifera cultivars and V. vinifera ssp. silvestris individuals have been subjected to the RAPD analysis in order to estimate the genetic diversity existing within this germplasm. 44 decamer primers of arbitrary sequence have been used for PCR and reproducible band profiles have been obtained. The distribution of the individualized polymorphic DNA markers has not turned out to be different in a remarkable way between cultivated and wild grapevines but this RAPD approach provides for some characteristics useful to analyze genetic relationships even within the Vitis vinifera species

Designing high efficiency glow discharge cleaning systems

In this paper we present our studies about the choices of anode design and operational regime in order to get high efficiency glow discharge cleaning of the first wall of a fusion device. We analyzed a database of toroidal and poloidal profiles of the ion current density at the wall, measured by electrostatic probes embedded in RFX-mod first wall tiles, taken in different configurations. The ion current at the wall, both global and local, is in fact strictly connected to the cleaning efficiency, since during glow discharge the wall is physically sputtered by the ions. We found that small size anodes and high in-vessel pressure lead to the peaking of the current profile around the anodes locations, and we experimentally characterized this effect. Instead, we found that anode radial position in the poloidal section has negligible effect on current density profile, even when the anodes are placed at the first wall. Finally, the most convenient operational regime, in terms of pressure and current, has been proposed. Keywords: RFX-mod, Glow discharge, Wall cleaning, Ion current profile, Anode desig

Leaf monoterpene emission limits photosynthetic downregulation under heat stress in field-grown grapevine

Rising temperature is among the most remarkably stressful phenomena induced by global climate changes with negative impacts on crop productivity and quality. It has been previously shown that volatiles belonging to the isoprenoid family can confer protection against abiotic stresses. In this work, two Vitis vinifera cv. ‘Chardonnay’ clones (SMA130 and INRA809) differing due to a mutation (S272P) of the DXS gene encoding for 1-deoxy-D-xylulose-5-phosphate (the first dedicated enzyme of the 2C-methyl-D-erythritol-4-phosphate (MEP) pathway) and involved in the regulation of isoprenoids biosynthesis were investigated in field trials and laboratory experiments. Leaf monoterpene emission, chlorophyll fluorescence and gas-exchange measurements were assessed over three seasons at different phenological stages and either carried out in in vivo or controlled conditions under contrasting temperatures. A significant (p < 0.001) increase in leaf monoterpene emission was observed in INRA809 when plants were experiencing high temperatures and over two experiments, while no differences were recorded for SMA130. Significant variation was observed for the rate of leaf CO2 assimilation under heat stress, with INRA809 maintaining higher photosynthetic rates and stomatal conductance values than SMA130 (p = 0.003) when leaf temperature increased above 30 °C. At the same time, the maximum photochemical quantum yield of PSII (Fv/Fm) was affected by heat stress in the non-emitting clone (SMA130), while the INRA809 showed a significant resilience of PSII under elevated temperature conditions. Consistent data were recorded between field seasons and temperature treatments in controlled environment conditions, suggesting a strong influence of monoterpene emission on heat tolerance under high temperatures. This work provides further insights on the photoprotective role of isoprenoids in heat-stressed Vitis vinifera, and additional studies should focus on unraveling the mechanisms underlying heat tolerance on the monoterpene-emitter grapevine clone

Genetic relationships among local Vitis vinifera cultivars from Campania (Italy)

A total of 114 accessions putatively corresponding to 69 local grape cultivars from Campania (Southern Italy) were analysed with 8 microsatellite markers (VVS2, VVMD5, VVMD7, VVMD25, VVMD27, VVMD31, VrZAG62 and VrZAG79) in order to evaluate their genetic diversity and relationships. According to their unique genotype at SSR loci finally 56 varieties were found. Interesting cases of synonymy, i.e. Greco di Tufo and Asprinio, Palummina and Piedirosso, and homonymy were disclosed. Pairwise genetic distances were calculated between all cultivars. Clustering of cultivars did not reflect their current distribution and this suggests that grape cultivars of Campania might have been introduced from various and distinct geographic areas

Ampelometric evaluation of wild grape (Vitis vinifera L. ssp. sylvestris (C.C. Gmel.) Hegi) accessions in the germplasm collection of FEM-IASMA, Italy

In this paper, 45 wild grapevine accessions collected during two consecutive years were compared for 36 ampelometric traits using digital image analysis. The sample set contained male and female individuals from different geographic regions: Germany, North Italy, Central Italy, South Italy, Sardinia and Turkey. The leaf morphological data from the collected samples suggest that geographic origin, gender and vintage could have an effect on ampelometric traits in this species

Design of the new electromagnetic measurement system for RFX-mod upgrade

A major modification of the RFX-mod toroidal load assembly has been decided in order to improve passive MHD control and to minimize the braking torque on the plasma, thus extending the operational space in both RFP and Tokamak configurations. With the removal of the vacuum vessel, the support structure will be modified in order to obtain a new vacuum-tight chamber and the first wall tiles will be directly in front of the passive stabilizing shell inside of it, so increasing both the poloidal cross section and the plasma-shell proximity. This implies the design of a new vacuum fit electromagnetic measurement system. The new local probes will be installed in vacuum onto the copper shell, behind the graphite tiles, and shall operate up to a maximum temperature of 180\ub0C to allow for baking cycles for first wall conditioning. Because of the reduced room available, tri-axial pickup probes have been designed, with the additional advantage of allowing the minimization of alignment errors. The paper describes the detailed design of the new probe set, in particular highlighting advantages and effectiveness of different probe solutions. Preliminary tests carried out on local probe prototypes to characterize their electromagnetic behaviour are also reported

The parentage of 'Sangiovese', the most important Italian wine grape

A previous microsatellite study pointed out a possible parent-offspring relationship between 'Sangiovese', the most widespread red grape cultivar in Italy, and 'Ciliegiolo', an ancient Tuscan variety. Testing 'Sangiovese' as a parent of 'Ciliegiolo', we searched for the putative other parent in our extensive, private and standardized database, but we did not find any candidate. Testing 'Ciliegiolo' as a parent of 'Sangiovese', we found four candidate cultivars. After the analysis of 50 microsatellites, only one stood the paternity test and we established with a strong statistical support that 'Sangiovese' is a progeny of 'Ciliegiolo' and 'Calabrese di Montenuovo', an obscure grapevine from Campania, Italy. This cultivar does not have a registered name and is supposed to have been introduced from Calabria. Among 180 additional local grape cultivars from Calabria, Campania or Tuscany, we did not find any matching variety. As a consequence, we propose to adopt the name 'Calabrese di Montenuovo' for this grape cultivar. In addition, we found relatives of 'Sangiovese' and 'Calabrese di Montenuovo' in Calabria, thus strongly suggesting a Calabrian origin for 'Calabrese di Montenuovo' and indicating that 'Sangiovese' has ancestors and/or progenies in Tuscany and in Southern Italy.