1. Epidemiology of Flavescence dorée and hazelnut decline in Slovenia : geographical distribution and genetic diversity of the associated 16SrV phytoplasmasZala Kogej Zwitter, Gabrijel Seljak, Tjaša Jakomin, Jakob Brodarič, Ana Vučurović, Sandra Pedemay, Pascal Salar, Sylvie Malembic-Maher, Xavier Foissac, Nataša Mehle, 2023, original scientific article Abstract: Flavescence dorée (FD) phytoplasma from 16SrV-C and -D subgroups cause severe damage to grapevines throughout Europe. This phytoplasma is transmitted from grapevine to grapevine by the sap-sucking leafhopper Scaphoideus titanus. European black alder and clematis serve as perennial plant reservoirs for 16SrV-C phytoplasma strains, and their host range has recently been extended to hazelnuts. In Slovenia, hazelnut orchards are declining due to 16SrV phytoplasma infections, where large populations of the non-autochthonous leafhopper Orientus ishidae have been observed. To better characterise the phytoplasma-induced decline of hazelnut and possible transmission fluxes between these orchards and grapevine, genetic diversity of 16SrV phytoplasmas in grapevine, hazelnut and leafhoppers was monitored from 2017 to 2022. The nucleotide sequence analysis was based on the map gene. The most prevalent map genotype in grapevine in all wine-growing regions of Slovenia was M54, which accounted for 84 % of the 176 grapevines tested. Besides M54, other epidemic genotypes with lower frequency were M38 (6 %), M51 (3 %), M50 (2 %) and M122 (1 %). M38, M50 and M122 were also detected in infected cultivated hazelnuts and in specimens of O. ishidae leafhopper caught in declining hazelnut orchards. It suggests that this polyphagous vector could be responsible for phytoplasma infection in hazelnut orchards and possibly for some phytoplasma exchanges between hazelnuts and grapevine. We hereby describe new genotypes: M158 in grapevine as well as four never reported genotypes M159 to M162 in hazelnut. Of these four genotypes in hazelnut, one (M160) was also detected in O. ishidae. Analysis of additional genes of the new genotypes allowed us to assign them to the VmpA-III cluster, which corresponds to the 16SrV-C strains previously shown to be compatible with S. titanus transmission. Keywords: phytoplasmas, haselnuts, grapevine, Flavescence dorée, epidemiology, plant disease Published in DiRROS: 26.07.2023; Views: 453; Downloads: 279 Full text (3,82 MB) This document has many files! More... |
2. The physiological impact of GFLV virus infection on grapevine water status : first observationsAnastazija Jež Krebelj, Maja Cigoj, Marija Stele, Marko Chersicola, Maruša Pompe Novak, Paolo Sivilotti, original scientific article Keywords: grapevine, water status, virus infection, GFLV, xylem vessel occlusion, gene expression Published in DiRROS: 06.09.2022; Views: 760; Downloads: 253 Full text (4,44 MB) |
3. Effect of cluster thinning within the grapevine varietyKatja Šuklje, Anastazija Jež Krebelj, Tanja Vaupotič, Franc Čuš, 2022, original scientific article Keywords: grapevine, cluster thinning, Welschriesling, thiols, terpenes, yield, yield parameters, wine parameters Published in DiRROS: 06.09.2022; Views: 655; Downloads: 180 Full text (1015,35 KB) |
4. Yield reduction through cluster or selective berry thinning similarly modulates anthocyanins and proanthocyanidins composition in Refosco dal peduncolo rosso (Vitis vinifera L.) grapesPaolo Sivilotti, Rachele Falchi, Joshua Vanderweide, Paolo Sabbatini, Marijan Bubola, Andreja Vanzo, Klemen Lisjak, Enrico Peterlunger, Jose Carlos Herrera, 2020, original scientific article Keywords: Grapevine, Yield reduction, Selective thinning, Tannins, Anthocyanins, vinska trta, grozdje, pridelek, redukcija pridelka, redčenje, tanini, antociani, kemična sestava Published in DiRROS: 06.05.2020; Views: 2064; Downloads: 260 File (1,07 MB) |