Cluster-Zone Leaf Removal and GA3 Application at Early Flowering Reduce Bunch Compactness and Yield per Vine in Vitis vinifera cv. Pinot Gris

Compact bunches have been often associated with higher susceptibility to Botrytis cinerea and therefore reduction in berry quality in grapevine. The objective of this study was to evaluate three management methods (early leaf removal, gibberellic acid, and their combination) for reducing bunch compactness in Vitis vinifera cv. Pinot gris trained in two different training systems with contrasting vigor (Guyot and pergola). Treatments were applied at BBCH 62 or BBCH 65 and yield components, total soluble solids, fruit set, and bunch compactness parameters were evaluated. Both treatments individually reduced berry number, mean bunches weight and bunches compactness as well as yield per vine when compared to control-untreated vines. However, no major differences were observed when both the treatments were applied in combination for Guyot or pergola although a higher reduction in yield was detected for Guyot and a significant increase in total soluble solids was observed in pergola. Our study suggests that intense leaf removal and gibberellic acid applied at early flowering can help reducing bunch compactness in Pinot gris and showing it in two training systems. In particular, leaf removal represents a valuable alternative to plant growth regulators (i.e., gibberellic acid) as applicable in organic viticulture.

Stable Cu Isotope Ratios Show Changes in Cu Uptake and Transport Mechanisms in Vitis vinifera Due to High Cu Exposure

Even though copper (Cu) is an essential plant nutrient, it can become toxic under certain conditions. Toxic effects do not only depend on soil Cu content, but also on environmental and physiological factors, that are not well understood. In this study, the mechanisms of Cu bioavailability and the homeostasis of Vitis vinifera L. cv. Tannat were investigated under controlled conditions, using stable Cu isotope analysis. We measured Cu concentrations and δ65Cu isotope ratios in soils, soil solutions, roots, and leaves of grapevine plants grown on six different vineyard soils, in a 16-week greenhouse experiment. The mobility of Cu in the soil solutions was controlled by the solubility of soil organic matter. No direct relationship between Cu contents in soils or soil solutions and Cu contents in roots could be established, indicating a partly homeostatic control of Cu uptake. Isotope fractionation between soil solutions and roots shifted from light to heavy with increasing Cu exposure, in line with a shift from active to passive uptake. Passive uptake appears to exceed active uptake for soil solution concentrations higher than 270 μg L–1. Isotope fractionation between roots and leaves was increasingly negative with increasing root Cu contents, even though the leaf Cu contents did not differ significantly. Our results suggest that Cu isotope analysis is a sensitive tool to monitor differences in Cu uptake and translocation pathways even before differences in tissue contents can be observed.

Modeling the technology of identification of wine materials and wines by PCR analysis of microsatellite loci of grapevine chloroplast DNA

Использование полиморфных микросателлитных локусов ДНК является одним из подходов к аутентификации виноматериалов и вин. При этом SSR-маркеры хлоропластной ДНК имеют большую копийность мишени на клетку и менее подвержены деградации из-за содержания в органеллах с двойной мембраной. Целью настоящей работы являлось моделирование технологии идентификации виноматериалов и вин ПЦР-анализом микросателлитных локусов хлоропластной ДНК винограда. Подобраны условия экстракции нуклеиновых кислот, постановки ПЦР с соответствующими наборами праймеров и электрофоретической детекции, направленные на практическое воспроизведение генетического тестирования пробоподготовленного биоматериала из осаждаемого винного дебриса. Представлены наглядные результаты выравнивания частичных нуклеотидных последовательностей аллелей микросателлитных локусов хлоропластной ДНК Vitis vinifera L. Проанализирована разделяющая способность метода горизонтального электрофореза в геле «Spreadex EL 300» in silico моделированием генерируемых аллельспецифичных фрагментов, позволяющая идентифицировать известные хлоротипы винограда даже при постановке ПЦР с ограниченными наборами праймеров, нацеленных на локусы cpSSR3, cpSSR5, cpSSR10, NTCP12 и ccSSR9. The use of polymorphic microsatellite DNA loci is one of the approaches to the authentication of wine materials and wines. At the same time, SSR markers of chloroplast DNA have a large target copy number per cell and are less susceptible to degradation due to their content in organelles with a double membrane. The aim of this work was to simulate the technology of identification of wine materials and wines by PCR analysis of microsatellite loci of grapevine chloroplast DNA. The conditions for the extraction of nucleic acids, PCR with the corresponding sets of primers and electrophoretic detection were selected, aimed at the practical reproduction of genetic testing of the sample prepared biomaterial from the precipitated wine debris. Illustrative results of the alignment of partial nucleotide sequences of alleles of microsatellite loci of Vitis vinifera L. chloroplast DNA are presented. The separating ability of the method of horizontal electrophoresis in «Spreadex EL 300» gel by in silico modeling the generated allele-specific fragments, which makes it possible to identify the known chlorotypes of grapevine with a limited set of primers targeting loci (cpSSR3, cpSSR5, cpSSR10, NTCP12 and ccSSR9) has been analyzed.