Berry Skins (berry + skins)

Distribution by Scientific Domains

Selected Abstracts

Age-dependent Grey Mould Susceptibility and Tissue-specific Defence Gene Activation of Grapevine Berry Skins after Infection by Botrytis cinerea

M. Kretschmer
Abstract The correlation between the degree of maturity of grapevine berries and their susceptibility to infection by the grey mould fungus Botrytis cinerea was studied. Artificial inoculation with B. cinerea conidia of detached berries from cultivars Riesling and Pinot noir revealed an increasing susceptibility during the last weeks of berry ripening. Wound inoculation resulted in increased lesion formation when compared with inoculation of non-wounded berry skins. Lesion development after non-wounding inoculation was stimulated by the addition of nutrients. Riesling berries were more readily infected than Pinot noir berries, indicating that the Riesling berry skin is more easily colonized by the grey mould fungus. Analysis of defence gene activation in the berry skin tissue revealed increased transcript levels of phenylalanine ammonium lyase and stilbene synthase after inoculation with B. cinerea conidia, while mRNA abundance of osmotin was similar in inoculated and non-inoculated tissue. Our data indicate that properties of the grape berry skin, including its ability for infection-induced defence gene activation, are important for the outcome of grey mould infections. [source]

Modifications of mechanical characteristics and phenolic composition in berry skins and seeds of Mondeuse winegrapes throughout the on-vine drying process,

Luca Rolle
Abstract BACKGROUND: Among several common drying systems used in the enological sector the dry-on-vine (DOV) method assumes particular importance because famous wines such as Sauternes, Tokay and Ice Wines are produced by grapes dried using this system. Knowledge about trends in mechanical properties and phenolic composition during on-vine grape drying is scarce. The objective of this current study is therefore to increase the knowledge on these aspects. RESULTS: Berry skin break energy (+0.10 N) and berry skin thickness (+69 µm) values increase during grape dehydration, while the peduncle detach force decreases (,0.86 N). Large reductions in the anthocyanin content have also been observed (,40%), but their profile does not show significant changes. Seed hardness (,7.10 N, ,1.40 mJ) decreases during the withering, and higher seed springiness has been observed. Seed proanthocyanidins (+2050 mg kg berry,1) and flavanols vanillin assay (+670 mg kg berry,1) increase progressively throughout the withering. In contrast, a distinct lowering of these substances in the skins was noted. CONCLUSION: Many modifications in the chemical,physical characteristics of berries of Mondeuse winegrapes throughout the DOV process were found. The mechanical characteristics of grapes, in particular the peduncle detachment force, are important parameters in assessing their suitability for the drying-on-plant process. Copyright © 2009 Society of Chemical Industry [source]

Phenological resistance of grapes to the green June beetle, an obligate fruit-eating scarab

D.L. Hammons
Changes in fruit characteristics associated with ripening increase the vulnerability of crops to insect depredation, making it difficult for growers to protect cultivated fruits from pest injury close to harvest. This study evaluated phenological resistance, the use of cultivars that ripen before or after peak pest activity, for reducing injury to grapes (Vitis spp.) by the green June beetle (GJB) (Cotinis nitida), an obligate feeder on soft, ripe fruits. Accumulation of sugars, softening of berry skins and recruitment of GJB feeding aggregations were monitored on replicated vines of early-, mid- and late-season ripening cultivars that require from 85 to 125 growing days from bloom to harvest. GJB flight peaked in late July and early August coinciding with later stages of veraison of early-season ripening cultivars which recruited numerous GJB feeding aggregations resulting in >95% crop loss. Small (1,2 weeks) phenological differences between mid-season ripening cultivars and peak GJB flight translated to marked differences in injury, whereas cultivars that ripened in mid-August or later, after GJB flight had waned, sustained little or no damage. Trapping experiments confirmed that the tougher berries and low sugar content of less-ripe fruit clusters inhibited beetle feeding and induction of yeast-mediated volatiles responsible for GJB host-location. Implications of these findings for sustainable or organic management of GJB and other near-harvest fruit pests are discussed. [source]

Anthocyanin profile of Spanish Vitis vinifera L. red grape varieties in danger of extinction

Abstract This paper reports on a study of the anthocyanin fraction in berry skins of ten minority red and pink grapevine varieties from Castilla-La Mancha (Spain) and two traditional varieties from this growing region, Tempranillo and Garnacha Tinta, as references. These varieties were correctly identified beforehand by analysing six microsatellite regions recommended by the GENRES 081 project; five varieties were identified with genotypes identical to those described previously, and five new genotypes not described for any variety according to the literature consulted. Grape skin extracts of each variety were analysed by HPLC-UV-Vis, and four perfectly differentiated anthocyanin profiles were obtained. In six out of ten varieties (Churriago, Unknown 1, Unknown 2, Ariño, Brujidera and Moravia Agria) the major anthocyanin was malvidin-3-glucoside (39%). Tinto Velasco contained more than 29% delphinidin-3-glucoside, Gordera Roja and Teta de Vaca Tinta more than 40% peonidin-3-glucoside, and Rojal more than 29% cyanidin-3-glucoside. Results of this work point out the existence of unusual anthocyanic profiles in several of these indigenous varieties, and highlight the necessity of studying the effects of variety on other flavonoids and their impact on wine colour. [source]