The kinetics of grape ripening revisited through berry density sorting

International audienceAim: In this study, ripening and heterogeneity in density-sorted berries were investigated, with the aim of more clearly understanding the kinetics of water uptake and sugar, acid and anthocyanin accumulation in the fruit of a new, disease-resistant hybrid.Methods and results: The 3184-1-9N hybrid, grown in a semi-arid climate in the South of France, was used. Its genotype is the result of several backcrosses of a Muscadinia Vitis vinifera F1 hybrid with several V. vinifera varieties. From the end of the green plateau to the over-ripening stage, single berries were sampled weekly and sorted by density, to monitor the advancement of ripening and the heterogeneity of grapevine fruit development at population level. Fruit firmness, density, fresh weight, primary metabolite content (sugars and organic acids), secondary metabolite content (anthocyanins), potassium content and pH were measured in berries from each density class. The data showed that softening and hexose accumulation occurred before fruit pigmentation. Based on malic acid and anthocyanin concentration relative to sugar concentration in density-sorted grapes, malic acid breakdown or dilution was promoted and anthocyanin accumulation reduced in late- or slow-ripening berries. In the different population structures in two experimental plots, berries with similar sugar concentration showed considerable heterogeneity in terms of volume and anthocyanin content, whereas pH, potassium content and acid content showed much more homogeneous kinetics.Conclusions: During ripening, analysis of density-sorted berries provides useful information about sugar concentration heterogeneity and its relation with organic acid and anthocyanin content. The stage at which grapes can be considered ripe may be precisely determined through periodic determination of mean berry volume or weight, to detect the cessation of phloem unloading and the onset of berry shrivelling. However, ripening and shrivelling berries generally coexist in the harvested population. Asynchronous berry development and berry weight heterogeneity greatly complicate determination of the timing of developmental events that are regulated at the single-berry level. Therefore, analysis of individual berries would seem to be an indispensable component of investigations of berry growth and development.Significance and impact of the study: Plotting water uptake and solute accumulation relative to sugar accumulation (as an internal clock) provides an original way to display grapevine fruit development data. Analysis of density-sorted berries has identified the relatively invariant fruit features, such as the minimum concentration of tartaric acid, the stability of potassium accumulation and pH, and conversely, the huge variations in berry size

Identification of allopatric clades in the cosmopolitan ophiuroid species complex Amphipholis squamata (Echinodermata). The end of a paradox?

Life history traits (absence of larval phase, small size and hermaphroditism) do not predispose Amphipholis squamata to dispersal, yet paradoxically it has a nearly cosmopolitan distribution. Recent phylogenetic analyses of 16S mitochondrial DNA (mt-DNA) sequences revealed that (1) Amphipholis squamata is a complex of diverging clades, each of them being found in the North Atlantic as well as in the South Pacific Ocean, and (2) genetic structure is low along the coasts of New Zealand, leading the authors to conclude that rafting may allow important gene flow in this taxon and possibly worldwide distribution of species. For the present study, we obtained 16S mt-DNA sequences from individuals of the Mediterranean Sea, which we analysed along with published data. We show that several sub-clades of previously identified clades display an allopatric distribution, either Atlantic versus Mediterranean, or Mediterranean and Atlantic versus New Zealand. Furthermore, none of the haplotypes (fro

Création d’une filière jus de raisin. Partie 2/3 : Évaluation qualitative physico-chimique et sensorielle des jus de raisins aux caractéristiques prédéfinies

Création d’une filière jus de raisin. Partie 2/3 : Évaluation qualitative physico-chimique et sensorielle des jus de raisins aux caractéristiques prédéfinie

Analyse des risques psychosociaux et de la qualité de vie au travail. Diagnostic et préconisations (unité expérimentale Pech Rouge)

il s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : ACTIVITY_REPORTAnalyse des risques psychosociaux et de la qualité de vie au travail. Diagnostic et préconisations (unité expérimentale Pech Rouge

How genetics and breeding do provide options to sustain wine production to face climatic warming issues ?

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Genetic diversity provides relevant prospects to sustain wine industry facing warming issues

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New vineyard fields: Grape Juice. Selection of grapevine species, juice making, stabilization / Nouvelle filière : jus de raisin. Sélection des cépages, élaboration, stabilisation

Proposed by FOULON-SOPAGLY society and INRA, a six years applied research program was developed in France to enable creation of create specific lines to elaborate high quality juice with new adapted grapevine varieties and specialized vineyards, with adapted technology. 448 vine varieties from INRA Vassal first international collection of grapevine species were evaluated to finally select 14: 2 V.vinifera,9 hybrids, and 3 from INRA creation (ref A. Bouquet) by hybridization. These last references, obtained from 4 or 5 back crossing between Muscadinia. rotondifolia.X.V.vinifera, have in particular a high level of resistance against mildew and oidium.These varieties have RUN 1 and RPV1. resistance genes, with several other secondary genes on one chromosome locus. This makes access to organic market easier. Agronomic criteria are studied for this selection. Among the 14 selected grapevine species, some have high level of polyphenols (6 times more than alicante). Others (white and red) have a high aromatic potential. Others have a low sugar content 135 g/l to 150 g/l) and adapted sugar/ acidity ratio. -In the cellar: The absence of fermentation and alcohol requires optimization of the process for juice making. For example by increasing polyphenols extraction and colour stability by using thermo-treatment. Flash release process coupled with enzymatic soaking on grapes at 45°C for example, increases 2 or 3 fold polysaccharide juice content, and increases anthocyanins extraction and hence colour intensity. With this process the draining of grape marc and juice production increase. Pressure technology by on line horizontal decanter is possible. -In juice storehouse. Electro membrane process, (oenodia membrane process) with specific membranes gives possibilities to achieve two objectives on juice: - Decrease pH and increase acidity of juice and colour stabilization, without any additive

New vineyard fields: Grape Juice. Selection of grapevine species, juice making, stabilization

Proposed by FOULON-SOPAGLY society and INRA, a six years applied research program was developed in France to enable creation of create specific lines to elaborate high quality juice with new adapted grapevine varieties and specialized vineyards, with adapted technology. 448 vine varieties from INRA Vassal first international collection of grapevine species were evaluated to finally select 14: 2 V. vinifera, 9 hybrids, and 3 from INRA creation (ref A. Bouquet) by hybridization. These last references, obtained from 4 or 5 back crossing between Muscadinia. rotondifolia.X. V.vinifera, have in particular a high level of resistance against mildew and oidium.These varieties have RUN 1 and RPV1. resistance genes, with several other secondary genes on one chromosome locus. This makes access to organic market easier. Agronomic criteria are studied for this selection. Among the 14 selected grapevine species, some have high level of polyphenols (6 times more than alicante). Others (white and red) have a high aromatic potential. Others have a low sugar content 135 g/l to 150 g/l) and adapted sugar/ acidity ratio. -In the cellar: The absence of fermentation and alcohol requires optimization of the process for juice making. For example by increasing polyphenols extraction and colour stability by using thermo-treatment. Flash release process coupled with enzymatic soaking on grapes at 45◦C for example, increases 2 or 3 fold polysaccharide juice content, and increases anthocyanins extraction and hence colour intensity. With this process the draining of grape marc and juice production increase. Pressure technology by on line horizontal decanter is possible. -In juice storehouse. Electro membrane process, (oenodia membrane process) with specific membranes gives possibilities to achieve two objectives on juice: - Decrease pH and increase acidity of juice and colour stabilization, without any additive

Fruit diversity in <em>Vitis vinifera</em> L. to select varieties better coping with warming issues

International audienc