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Vitis species are shown to be susceptible, tolerant, or resistant to the Plasmopara viticola (Berk. & M. A. Curtis; Berl. & de Toni) pathogen. The obligate, biotrophic, and polycyclic P. viticola oomycete can infect any green organ of the host plant, including the shoots, leaves, inflorescences, tendrils, petioles, and green berries. It can therefore have a devastating effect on the host plant. Moreover, significant economic losses occur when effective control methods are not used when growing susceptible species and varieties. The most widespread and commercially significant Vitis species in the world is the grapevine (Vitis vinifera L.). Although the majority of grapevine varieties are susceptible to downy mildew, there are some variations in susceptibility among them. Croatia has a centuries-old heritage of grapevine cultivation. One hundred and twenty-five native varieties were developed and are still grown in Croatia's various geographical and climatic regions. It is therefore considered that in addition to variations in a wide range of biological and economic properties, they also differ in disease susceptibility. Aiming to determine the differences in susceptibility of Croatian native varieties to downy mildew, phenotyping of selected varieties was carried out using the following methods: leaf disc bioassay, measurement of chlorophyll fluorescence and multispectral imaging, and analysis of polyphenolic and volatile organic compounds in grapevine leaves. Polyphenolic and volatile organic compounds were analysed in leaves before and 24, 48, and 96 hours after inoculation with P. viticola suspension. Measurement of chlorophyll fluorescence and multispectral imaging was performed before inoculation and during six terms after inoculation. The leaf disc bioassay proved to be effective for classifying grapevine varieties into the OIV resistance classes to downy mildew. In addition, parameters of chlorophyll fluorescence, such as Fv/Fm, Fq'/Fm' and ETR, were useful in distinguishing infected from non-infected leaf discs shortly after inoculation, that is, before the appearance of visible symptoms of the disease. Moreover, the Fq'/Fm' and qP parameters helped distinguish between varieties with different susceptibility to P. viticola. The results of the polyphenolic compound analysis clearly distinguished the native varieties into the OIV resistance classes. Resistance was found to be dependent on the composition and content of polyphenolic compounds present in the leaves before inoculation. In all terms following the P. viticola inoculation, the stilbene resveratrol-3-O-glucoside content was higher in infected leaves compared to uninfected. Finally, volatile organic compound analysis can be used to distinguish infected from noninfected samples as well as resistant control genotypes (Solaris, Vitis riparia Michx.) from V. vinifera varieties. Nevertheless, using this approach does not allow for the division of native varieties into the OIV resistance classes. Less susceptible native grapevine varieties that belong to OIV class 5 (Malvazija istarska, Ranfol, and Teran) could be interesting to use in breeding programs aiming to produce highquality genotypes tolerant to main fungal diseases. Vrste roda Vitis (loze) osjetljive su, tolerantne ili otporne na uzročnika plamenjače Plasmopara viticola (Berk. & M. A. Curtis; Berl. & de Toni). Vinova loza (Vitis vinifera L.) najuzgajanija je vrsta loza u svijetu iako je većina sorata vinove loze osjetljiva na plamenjaču. Ova bolest ima izrazito devastirajuće djelovanje kad se prilikom uzgoja ne primjenjuju kemijska sredstva za zaštitu bilja. Oomiceta P. viticola je obligatni, biotrofni i policiklički patogen koji može inficirati sve zelene organe biljke domaćina, kao što su mladice, listovi, cvatovi, vitice, peteljke i zelene bobe. Optimalni uvjeti za rast i razvoj ovog patogena su visoka vlažnost i umjerena temperatura zraka. U takvim uvjetima patogen razvija nekoliko ciklusa vegetativnog razmnožavanja, uzrokujući značajan pad prinosa i kvalitete grožđa. Zbog toga je primjena fungicida neizbježan tehnološki postupak pri uzgoju osjetljivih sorata vinove loze, iako te agrokemikalije mogu štetno djelovati na okoliš. Plasmopara viticola podrijetlom je s američkog kontinenta pa su američke vrste (Vitis labrusca L., Vitis riparia Michx., Vitis rupestris Scheele i Muscadinia rotundifolia Small) koevolucijom na istom području razvile visoku ili potpunu otpornost. Donedavno se smatralo da je europska loza V. vinifera neotporna na plamenjaču i pepelnicu, odnosno da ne postoji značajna genetska varijabilnost u otpornosti unutar sorata vinove loze. Međutim, u novije su vrijeme kod nekih od njih, kao što su 'Kishmish vatkana', 'Dzhandzhal kara' i 'Mgaloblishvili', identificirani geni otpornosti, što ih čini vrijednim izvorom gena za oplemenjivačke programe s ciljem stvaranja visokokvalitetnih sorata otpornih na ekonomski najznačajnije bolesti. Pretpostavlja se da, zbog višestoljetnog uzgoja vinove loze u Hrvatskoj i njezine prilagodbe specifičnim okolišnim uvjetima, među hrvatskim autohtonim sortama također postoje razlike u osjetljivosti na bolesti. S ciljem utvrđivanja osjetljivosti hrvatskih autohtonih sorata na plamenjaču, provedeno je istraživanje koje je obuhvatilo odabrane sorte te nekoliko otpornih i osjetljivih kontrolnih genotipova koristeći sljedeće metode fenotipizacije: metoda lisnih diskova, mjerenje fluorescencije klorofila i multispektralno snimanje lisnih diskova te analiza polifenolnih i hlapljivih organskih spojeva u listovima. Metoda lisnih diskova provedena je u kontroliranim laboratorijskim uvjetima sukladno deskriptoru 452-1 Međunarodne organizacije za vinovu lozu i vino (engl. International Organisation of Vine and Wine, OIV). Na temelju toga, svaki je genotip svrstan u odgovarajući razred otpornosti pri čemu su genotipovi svrstani u razred 1 najosjetljiviji, a oni svrstani u razred 9 potpuno otporni na plamenjaču. Mjerenje fluorescencije klorofila i multispektralno snimanje provedeno je pomoću instrumenta CropReporterTM tijekom sedam termina. Prvo mjerenje provedeno je na netretiranim lisnim diskovima, a završno kad su se razvili vidljivi simptomi bolesti (sporulacija). Polifenolni spojevi analizirani su tekućinskom kromatografijom visoke djelotvornosti (engl. high-performance liquid chromatography, HPLC), a hlapljivi organski spojevi primjenom vezanog sustava plinski kromatograf-spektrometar masa (engl. gas chromatography-mass spectrometry, GC-MS). U tu svrhu, analizirani su listovi uzorkovani prije tretiranja te 24, 48 i 96 sati nakon inokulacije P. viticola suspenzijom. Lisni diskovi i listovi inokulirani su suspenzijom koncentracije 2 × 105 spora/mL raspršivanjem po naličju. Suspenzija je dobivena umakanjem listova sa svježe razvijenom sporulacijom u ultračistu vodu do zamućenja. Utvrđeno je da je metoda lisnih diskova učinkovita za razvrstavanje sorata vinove loze u OIV razrede otpornosti na uzročnika plamenjače vinove loze. Parametri fluorescencije klorofila, odnosno Fv/Fm, Fq'/Fm' i ETR, razlikovali su inficirane od neinficiranih lisnih diskova, a pomoću parametara Fq'/Fm' i qP moguće je razlikovati slabije i jače osjetljive sorte ubrzo nakon zaraze, odnosno prije pojave vidljivih simptoma bolesti. Rezultati analize polifenolnih spojeva jasno su razdvojili autohtone sorte u razrede otpornosti pri čemu je utvrđeno da otpornost ovisi o sastavu i sadržaju polifenolnih spojeva u listovima prije inokulacije. Povećan sadržaj stilbena resveratrol-3-O-glukozida razlikovao je inficirane od neinficiranih listova tijekom svih termina nakon inokulacije. Sadržaj piceatanola i ukupnih stilbena razlikovao je potpuno otporan OIV razred 9 (Vitis riparia Michx.) od ostalih OIV razreda čime su potvrđena njihova snažna antimikrobna svojstva. Na temelju polifenolnih profila V. vinifera sorata, utvrđeno je da su uglavnom flavonol glikozidi odgovorni za manju osjetljivost sorata koje sadrže višu koncentraciju ovih spojeva. Analizom hlapljivih organskih spojeva moguće je razlikovati otporne kontrolne genotipove od V. vinifera sorata kao i inficirane od neinficiranih uzoraka. Iako ovom metodom nije moguće razdvojiti autohtone sorte u razrede otpornosti, rastući sadržaj nekoliko detektiranih hlapljivih spojeva nakon inokulacije zajedničko je svojstvo manje osjetljivih autohtonih sorata i otpornih kontrolnih genotipova ('Solaris', Vitis riparia Michx.). Manje osjetljive autohtone sorte koje pripadaju OIV razredu 5 ('Malvazija istarska’, ‘Ranfol’ i ‘Teran’) mogle bi biti zanimljive za korištenje u oplemenjivačkim programima kojima je cilj proizvesti visokokvalitetne sorte tolerantne na najznačajnije gljivične bolesti.

Postponing pruning until early spring has been shown to be an effective way of delaying vine phenology. We investigated the effects of the timing of late winter pruning on ‘Portugieser’ vines in northwestern Croatia (2021), on yield, berry primary and phenolic composition. Late winter pruning (at the time of budbreak of basal buds and when two to three leaves were separated) was compared with standard winter pruning. Late winter pruning at budbreak resulted in grapes with the highest total phenolic and anthocyanin content and the lowest sugar and flavonol content at harvest, while late winter pruning performed when two to three leaves were separated had the highest titratable acidity and lowest total phenolic content.

Šljiva (Prunus domestica L.) je koštičava voćna vrsta vrlo cijenjena zbog poželjnih senzornih i nutritivnih svojstava plodova. Plodovi se konzumiraju svježi ili se prerađuju. Zbog relativno visokog sadržaja šećera i niže ukupne kiselosti plodovi sorte 'Stanley' predstavljaju dobar izbor za proizvodnju voćnih vina. Voćna vina proizvode se aktivnošću kvasaca u procesu alkoholne fermentacije. Obzirom da metabolizmom kvasaca nastaje čitav niz metabolita, izborom odgovarajuće vrste ili soja utječe se na tip vina koje se proizvodi. Cilj ovog rada bio je istražiti utjecaj različitih vrsta kvasaca na osnovni kemijski sastav, koncentraciju ukupnih fenola i ukupnih antocijana voćnih vina od šljive. Korištene su dvije različite vrste kvasaca Lalvin ICV D21 – Saccharomyces cerevisiae i Lalvin EC 1118 – Saccharomyces bayanus. Vina proizvedena aktivnošću kvasca ICV D21 imala su viši sadržaj alkohola, ekstrakta te ukupnih fenola i ukupnih antocijana. Rezultati ovog istraživanja ukazuju na značajan utjecaj vrste kvasca na kemijski sastav i kakvoću voćnih vina od šljive., Plum (Prunus domestica L.) is highly valued drupe because of its desirable sensory and nutritional properties. The fruits are consumed fresh or processed. The fruits of the ´Stanley´ variety are a good choice for the production of fruit wines due to their relatively high sugar content and lower total acidity. Fruit wines are produced by yeasts in the process of alcoholic fermentation. Yeast metabolism produces a number of metabolites, so we influence the type of the wine by choosing the appropriate strain. The aim of this study was to determine the influence of different yeast strains on the basic chemical composition, concentration of total phenols and total anthocyanins of plum fruit wines. Two different commercial yeasts were used, Lalvin ICV D21 - Saccharomyces cerevisiae and Lalvin EC 1118 - Saccharomyces bayanus. Wines produced under the influence of yeast ICV D21 had a higher content of alcohol, extract, total phenols and total anthocyanins. The obtained results of the research indicate a significant impact of yeast strains on the chemical composition and quality of plum fruit wines.

Since grapevine is highly susceptible to various pathogens, enormous amounts of pesticides are applied each season to achieve profitable production. One of the most destructive grapevine diseases is downy mildew, and their interaction has been in the spotlight for more than a decade. When it comes to a metabolome level, phenolic compounds are relevant to investigate due to their involvement in the plant immune system and known antifungal properties. Croatian grapevine germplasm is highly heterogeneous due to its long history of cultivation in diversified geographical regions. Since it has been found that native varieties react differently to the infection of Plasmopara viticola, the intention of this study is to define if the chemical background of the leaves, i.e., polyphenolic composition, is responsible for these dissimilarities. Therefore, the leaves of 17 genotypes, among which 14 were native and 3 were controls, were analyzed using high-performance liquid chromatography (HPLC) in four terms: before inoculation and 24, 48, and 96 h post inoculation (hpi). During this early phase, significant differences were found neither between the terms nor between the non-inoculated and inoculated samples, except for resveratrol-3-O-glucoside. By applying principal component analysis (PCA) using initial leaf polyphenolic composition, varieties of V. vinifera were clearly separated into three different groups corresponding to their International Organization of Vine and Wine (OIV) classes of susceptibility to P. viticola. Results obtained in this research suggest that the initial constitutive polyphenolic composition of the cultivar leaves has a crucial influence on their susceptibility to P. viticola, and this finding can be used to improve the success of grapevine breeding programs toward downy mildew resistance.

Povijesni dokumenti o uzgoju vinove loze na području Republike Hrvatske svjedoče da je krajem 19. stoljeća bilo oko 400 autohtonih sorata. Današnjim genetičkim istraživanja utvrđena su 103 različita genotipa. Cilj rada je iz dokumenata službene statistike prikazati udio autohtonih sorata u površinama pod vinogradima te udio u ukupnoj proizvodnji grožđa i vina u Hrvatskoj. Autohtone sorte u Hrvatskoj u 2020. godini zauzimaju 39, 1% ukupnih vinogradarskih površina. U 2019. godini udio autohtonih sorata u proizvodnji grožđa je bio 31, 1%, a vina 32%. Malvazija istarska, Plavac mali i Plavina zauzimaju 21% površina, a Malvazija Istarska, Plavac mali crni i Pošip bijeli 19% proizvodnje grožđa i 20% proizvodnje vina. Iako autohtone sorte zauzimaju skoro trećinu proizvodnje svakako bi kroz državne poticaje i sredstva iz Europskih fondova i dalje trebalo poticati povećanje vinogradarskih površina pod autohtonim sortama.

A long history of grapevine cultivation in diversified geographical regions in Croatia gave rise to a high number of native varieties. In the era of sustainable production, there is a growing demand to define their differences in susceptibility to downy mildew. By applying leaf disc bioassay in controlled laboratory conditions, it has been found that native varieties react differently to the infection of Plasmopara viticola. Therefore, they were ascribed to classes of resistance according to the OIV descriptor 452-1 [Leaf: degree of resistance to Plasmopara (leaf disc test)]. Chlorophyll fluorescence and multispectral imaging traits have been measured in time points before and upon inoculation to define which of them could be used as an early detector of infection and are these methods suitable for distinguishing genotypes of different susceptibility to downy mildew. Moreover, the leaves were analysed using high-performance liquid chromatography (HPLC) to define if their chemical background, i.e., polyphenolic composition, is responsible for native varieties’ different levels of resistance. It has been found that the leaf disc test is a simple method to perform, and it brings about trustworthy results when genotypes with a known level of resistance are comparatively evaluated. Chlorophyll fluorescence and multispectral imaging are promising tools for precise monitoring of the photosynthesis transmission inside a leaf tissue upon P. viticola inoculation. This utility could be used as a phenotyping method in the absence of the pathogen to define the level of genotype’s resistance to P. viticola. As far as secondary metabolites are concerned, polyphenolic compounds proved to be responsible for the discrimination of varieties among the OIV classes of resistance. It has been found that the constitutive polyphenolic profile contributes to the separation of susceptible OIV classes (1, 3, and 5) into three groups. The content of resveratrol-3-O-glucoside and total stilbenes discriminated non-infected and infected samples, whereas the content of piceatannol and total stilbenes discriminated completely resistant OIV class 9 (V. riparia) and the remaining OIV classes. Less susceptible grapevine varieties that belong to OIV class 5 (Malvazija istarska, Ranfol, Teran) could be interesting to use in breeding programs aiming to produce high-quality genotypes resistant to main fungal diseases.

An important aspect of wine geographic origin is related to grapevine varieties used for wine productionin specific winegrowing regions or countries. Grapevine germplasm is highly variable and classified into geographical groups. These classifications were recently confirmed by genetic studies, and further classified into genetic-geographic (GEN-GEO) groups. Secondary metabolites, namely polyphenolic and volatile organic compounds (VOCs), have crucial role in winemaking industry due to their influence on quality, colour, and sensory properties of wine. The aim of the research was to investigate the polyphenolic and volatile profiles of 50 grapevine varieties from different GEN-GEO groups. The groups are C2 (varieites from Italy and France), C7 (varieites from Croatia), and C8 (varieites from Spain and Portugal). Polyphenolic compounds analysed belonged to the classes of anthocyanins, flavan-3-ols, flavonols, phenolic acids, and stilbenes. Classes of VOCs analysed were carbonyls, alcohols, acids, esters, and terpenoids. The most abundant class of polyphenols were anthocyanins, followed by flavan-3-ols and flavonols, while carbonyls were the most abundant class of VOCs, followed by alcohols and sesquiterpenes. Using discriminant analysis, the GEN-GEO groups were clearly separated by their polyphenolic and volatile profiles. In the case of polyphenolic profiles, compounds contributing the most to the discrimination of groups belong to classes of hydroxycinnamic acids, flavan-3-ols, and flavonols. Furthermore, some of the compounds contributing to discrimination are found in relatively small amounts. Regarding the discrimination based on volatile profiles, GEO groups were discriminated by their overall volatile profile. C2 group contains higher amounts of carbonyl compounds and alcohols, while C8 group contains higher amounts of sesquiterpenes and acids. Group C7 is characterized by low content of VOCs. This data demonstrates that geographical origin, combined with genotype, also influences the overall polyphenolic and volatile profiles.

Grapevine (Vitis vinifera L.) is one of the oldest agricultural species. Wide application of this culture in the economy makes it one of the most important agricultural fruit culture in the world. Republic of Croatia is important gene center for native, as well as for introduced cultivars of grapevine, so the viticulture's aim is to conserve and revitalize its cultivation. Crypreservation is the most efficient procedure for the conservation of the plant material. In the cryopreservation procedure different preculture of microcuttings, cryoprotectants and steps during freezing can be toxic and make the stress within cultivars of grapevine. The aim of this study is the optimization of preculture medium for preculture of microcuttings with addition of antioxidants (salicylic acid) with the purpose of the successful growth of shoot tips of the cultivar 'Graševina'. The study was made on microcuttings of cultivar 'Graševina', planted on half-strength MS medium, with or without cytokinins benzylaminopurine and different concentrations of salicylic acids (0, 0.1, 0.5 and 1 mMol). The highest percentage of shooted microcuttings was achieved on the medium without the salicylic acid and BAP (68, 38%), and the lowest on the medium with addition of salicylic acid in concentration 0.1 mMol and supplement of 1µmol BAP (35, 00%). Microcuttings cryopreservation of cultivar 'Graševina' reached the highest results of regeneration in controled explants (15%) in comparison on the freezing ones (10%). Given results are implying that some additional studies should be done for successful cryopreservation of this cultivar.

Grapevine represents a significant crop in agricultural production in Croatia. Intensive work has been made on the Croatian autochthonous cultivars in the last two decades. A clone repository of autochthonous cultivars in virus-free conditions is safe and a legally regulated conservatory method of a specific crop's gene base. Considering different geographical origin of initial material, accessions can be multiplied in tissue culture presenting a much easier way than the classical propagation and ensuring a healthy plant material. The trial has covered 27 registered clones from 9 Croatian autochthonous cultivars. The material for in vitro establishment were 10 shoot tips from one vine of each clone. Vines are part of in situ mother blocks with the highest sanitary cleanliness. Material was taken in two periods, before and after flowering phenophase. Collected shoot tips were inoculated on a medium (Murashige and Skoog, 1 mg/l 6-benzylaminopurine + 0, 05 mg/l 3-indol-acetic acid). Regeneration of shoot tips was recorded after 6 weeks. Mature in vitro plants were subjected to acclimatization. Results achieved were in a range between 10-100% and the average percentage of regeneration is 30-40% in both periods. These preliminary research trials confirm the necessity for more detailed testing of tissue culture protocols for each cultivar of interest.

Elevated temperatures in spring and summer often advance flowering, veraison and harvest, resulting in grapes with higher sugar content, lower acidity and poor color development. Late winter pruning is an effective tool to delay fruit ripening and improve the chemical composition of grapes. A one- year study (2021) was carried out on the Portugieser grape variety grown in a vineyard in north-western Croatia, to study the effects of late winter pruning on berry primary and phenolic composition. Late winter pruning was performed at the time of basal budburst and when 2 to 3 leaves were separated, while winter pruning was a control treatment. Samples of grapes obtained in all three treatments were harvested at the same time. The treatments with late winter pruning reduced the sugar content of the grapes. Late winter pruning performed at budburst resulted in grapes with the highest total phenolic and anthocyanin content and the lowest flavonol content at harvest, while late winter pruning performed when 2 to 3 leaves were separated had the highest titratable acidity and the lowest total phenolic content. This study suggests that the method has rather positive effects on grape quality compared to standard winter pruning.

Agronomski fakultet Sveučilišta u Zagrebu provodi individualnu klonsku selekciju najvažnijih autohtonih sorata vinove loze kao i sorte Graševine kroz više različitih projekata od 2003. godine. Do sada je postupak selekcije završen kod 11 sorata, a izdvojena su i registrirana ukupno 34 klona. U sklopu projekta „Novi početak za stare hrvatske sorte vinove loze“ (KK.01.1.1.04.0031.) financiranog od strane Europske unije kroz Europske strukturne i investicijske fondove provedena je uspostava matičnih nasada najviših kategorija (predosnovni i osnovni), a u tijeku je uspostava certificiranih matičnih nasada svih registriranih klonova. U ovom katalogu donosimo opis osnovnih ampelografskih i proizvodnih svojstava registriranih klonova.

Saccharomyces cerevisiae najčešće je korištena vrsta kvasca u vinarskoj proizvodnji dok je vrsta Lachancea thermotolerans noviji pripadnik selekcioniranih ne-Saccharomyces kvasaca. Ističe se sposobnošću zakiseljavanja moštova niže ukupne kiselosti, iz toplih vinogradarskih regija, najčešće u sekvencijalnoj inokulaciji sa S. cerevisiae. Formiranje boje vina i sastav antocijana tijekom vinifikacije pod utjecajem su kvasaca, odnosno adsorpcijskih karakteristika stanične stjenke kvasca. Cilj ovog rada bio je utvrditi razlike u učinku sekvencijalne inokulacije komercijalnim sojevima L. thermotolerans x S. cerevisiae u usporedbi s tretmanima sa S. cerevisiae i epifitnim kvascima, na sastav antocijana u vinu ´Trnjak´. Rezultati analiza ukazali su na značajno niže koncentracije antocijana u tretmanu L. thermotolerans x S. cerevisiae.

In vitro culture obtain the tools to perform specific studies that it would be impossible to carry out with the whole plants grown on field or under greeenhouse conditions. Cryopreservation presents the long-term conservation without a metabolic changes of plant material and cryotherapy can be efficient in virus elimination. Tested cryopreservation protocols did not gave sufficient regeneration. Preculture media of cryopreservation profotocols was evaluated with Croatian grapevine cultivars (ꞌGraševinaꞌ, ꞌPlavac maliꞌ and ꞌPošipꞌ) with different antioxidants (salicylic acid, ascorbic acid and glutathione). The highest growth in vitro was achieved on the medium with the addition of glutathione and the lowest on the medium with addition of salicylic acid. The growth in vitro and regeneration after cryopreservation was depended on genotype and sanitary status. A reliable protocol for the regeneration after cryopreservation (within cryotherapy) should be defined for each grapevine cultivar. Virus elimination was tested by meristem tip culture with 18 Croatian cultivars, whereas, regeneration in vitro was between 6.82 and 53.22%, but virus elimination was achieved only with three cultivars and was very low (23.8%). Additionally, the method of conservation of grapevine cultivars by cultivation in isolated conditions of small glass containers (2L), was tested. Two cultivars were grown in containers in the growth chamber under controlled conditions. This study has revealed that the plants can be conserved this way for more than 2 years (ongoing trial). Plants grown this way can be the source of plant material for new in vitro introduction and multiplication. Overall, the presented methods should be further evaluated for broad application.

A long history of grapevine cultivation in diversified geographical regions in Croatia gave rise to a high number of native varieties. In the era of sustainable production, there is a growing demand to define their differences in susceptibility to downy mildew. By applying leaf disc bioassay in controlled laboratory conditions, it has been found that native varieties react differently to the infection of Plasmopara viticola. Therefore, they were ascribed to classes of resistance according to the OIV descriptor 452-1 [Leaf: degree of resistance to Plasmopara (leaf disc test)]. The leaves were analysed using high-performance liquid chromatography (HPLC) to define if their chemical background, i.e., polyphenolic composition, is responsible for native varieties’ different levels of resistance. The leaf disc test is a simple method to perform, and it brings about trustworthy results when genotypes with a known level of resistance are comparatively evaluated. Polyphenolic compounds proved to be responsible for the discrimination of varieties among the OIV classes of resistance. It has been found that the innate constitutive polyphenolic profile contributes to the separation of susceptible OIV classes (1, 3, and 5) into three groups. The content of resveratrol-3-O-glucoside and total stilbenes discriminated non-infected and infected samples, whereas the content of piceatannol and total stilbenes discriminated completely resistant OIV class 9 (V. riparia) and the remaining OIV classes. Less susceptible grapevine varieties that belong to OIV class 5 (Malvazija istarska, Ranfol, Teran) could be interesting to use in breeding programs aiming to produce high-quality genotypes resistant to main fungal diseases.

Wines from dried grapes have been produced for centuries in the Mediterranean. In Croatia Prošek is traditional dessert wine made form dried grapes. However, the traditional way of drying is increasingly neglected due to the inability to control conditions. Thus, the safest and fastest drying method is to use modern dryers. The aim of the study was to determine the dynamics of drying and changes in the quality of Plavina grapes in controlled conditions. The research was carried out at Baštica vineyard, where part of the grapes was treated with inactive yeasts (Lalvigne mature) at the beginning of vérasion, while non-treated grapes presented the control. The grapes were dried for 6 days in chambers at 40°C. After drying the mass of grapes decreased 25% in treated grapes and 35% in control. Significant difference was also observed in polyphenolic and volatile content of the treated grapes. The applied drying technology ensures the optimal health of the grapes, as well as production of new style of dessert wine and utilization of qualitative potential of Plavina cultivar.

Grapevine-downy mildew interaction is one the most challenging biotic stresses. In order to avoid undesirable features of non-vinifera species, usually used for resistance breeding, the resistance of cultivated (V. vinifera) varieties to the main diseases is in the spotlight again. Aiming to find differences among Croatian native grapevine varieties in susceptibility to downy mildew, whose causal agent is Plasmopara viticola, an experiment has been conducted. Young leaves of 14 Croatian native grapevine varieties, together with Chardonnay (susceptible control variety), Solaris (partially resistant variety) and Vitis riparia (resistant genotype) were sampled and used in this research. A leaf disc bioassay was applied according to the OIV descriptor 452-1 whereby the genotypes were ascribed to corresponding OIV classes 1, 3, 5, 7, and 9 from the most susceptible to the totally resistant ones. Polyphenolic compounds were quantified by high-performance liquid chromatography (HPLC). The results were analysed using one way ANOVA and the differences between the means were evaluated by Duncan’s multiple range test at a confidence level of 95 % (p < 0.05). Principal component analysis was performed to show the differences in the polyphenolic composition of grapevine leaves between non-inoculated and inoculated varieties belonging to OIV classes 1, 3 and 5 in different terms (24, 48 and 96 hpi) upon inoculation. Majority of evaluated native varieties (≈80 %) are highly susceptible or susceptible to P. viticola belonging to OIV classes 1 or 3, respectively. However, scarce sporulation (21-40 %) developed on leaf discs of the following varieties Malvazija istarska, Ranfol and Teran placed them to the OIV class 5. PCA clearly distinguished diverse classes of susceptibility among evaluated V. vinifera varieties based on their polyphenolic composition. Nonetheless, their polyphenolic composition in terms upon inoculation was not significantly different. Methods applied in this research proved to be reliable and complement one to another. Early changes in polyphenolic profiles upon inoculation were not found, although they served as a decisive feature for distinguishing classes of susceptibility which were previously obtained by artificial inoculation. Less susceptible grapevine varieties that belong to the class 5 could be of interest to use in breeding programs.

Otporne sorte vinove loze nezasluženo se vežu za negativne konotacije prvih križanaca koji su nastali na samom početku korištenja međuvrsne hibridizacije, odnosno u drugoj polovini 19. stoljeća. Korištenjem kvalitetnog materijala, pomno osmišljenih pokusa i znanstvenih dostignuća postupak oplemenjivanja danas je potpuno promijenio paradigmu od empirijskog načina rada do striktno ciljanog dizajna križanja čime u posljednjih dvadesetak godina nastaju sorte izvrsnih gospodarskih karakteristika uključujući visoku razinu otpornosti na plamenjaču i pepelnicu. Te sorte prikladne su za uzgoj vinove loze uz bitno manju uporabu fungicida, kao i za ekološki uzgoj. Zbog povoljna utjecaja na okoliš i zdravlje ljudi takvi načini proizvodnje u skladu su s ciljevima europske strategije „Od polja do stola”. Povijesni pregled oplemenjivanja, od dolaska američkih bolesti i štetnika na europski kontinent do najnovije generacije otpornih sorata, kao i procjena perspektive za njihovo šire prihvaćanje u proizvodnji, nalazi se u nastavku.

Graševina je gospodarski najvažnija i najraširenija bijela sorta vinove loze u Republici Hrvatskoj. Pored svih vrijednih spojeva, vino sadrži i teške metale koji u povišenoj koncentraciji mogu utjecati na kvalitetu vina. Njihov sadržaj u grožđu i vinu ovisi o sorti, klimi, tlu te primjeni poljoprivredne prakse u vinogradu i tehnoloških procesa u proizvodnji. Istraživanjem je analizirano 10 vina berbe 2017 godine sorte 'Graševina' iz vinogradarske podregije Hrvatsko Podunavlje (vinogorje Baranja, Srijem i Erdut). ICP-MS i ICP-OES metodama određene su koncentracije teških metala. Rezultati pokazuju da sva analizirana vina udovoljavaju propisanim standardima Pravilnika o proizvodnji vina.

Zlatarica vrgorska i Trnjak hrvatske su autohtone sorte koje se uzgajaju u podregiji Dalmatinska Zagora, posebice u vinogorjima Vrgorac i Imotski. Klonska selekcija spomenutih sorata započela je 2018. godine provedbom masovne pozitivne i sanitarne selekcije. Selekcija je provedena na deset lokacija unutar vinogorja Vrgorac te je izdvojeno 97 klonskih kandidata sorte Zlatarica vrgorska i 27 sorte Trnjak. Odabrani su pozitivni mutanti bez vizualnih simptoma zaraženosti virusima. Bazalni uzorci rozgve uzeti su 2019. godine tijekom zime sa svakog pojedinačno odabranog matičnog trsa. Prikupljeni uzorci testirani su na prisustvo četiri gospodarski najvažnija virusa serološkom metodom ELISA (enzyme linked immunosorbent assay): virus lepazatsog lista vinove loze (GFLV), virus mozaika vinove loze (ArMV), virusi uvijenosti lišća vinove loze 1 i 3 (GLRaV-1 i GLRaV-3). Prema dobivenim rezultatima, u pet uzoraka sorte Zlatarica vrgorska i 6 Trnjka crnog nije utvrđena prisutnost analiziranih virusa. Najrašireniji virus GLRaV-3 pronađen je u 69, 07 % biljaka kod sorte Zlatarica vrgorska te u 37, 04 % kod sorte Trnjak. Slijedi ga virus GLRaV-1 koji je prisutan u 55, 67 % biljaka sorte Zlatarica vrgorska i 62, 96 % sorte Trnjak. Prisustvo drugih virusa je značajno rjeđe pa tako nalazimo GFLV u 11, 34 % uzorka sorte Zlatarica vrgorska i u 37, 04 % sorte Trnjak. Virus ArMV nije pronađen u populaciji sorte Trnjak, dok je kod Zlatarice vrgorske pronađen u 13, 4 % analiziranih uzoraka.

Sorte vinove loze (Vitis vinifera L.) osjetljive su na plamenjaču, no ipak postoje razlike u razini njihove osjetljivosti na navedenu bolest. U svrhu određivanja razina osjetljivosti unutar bogate hrvatske germplazme vinove loze, provedeno je istraživanje tijekom 2018. i 2019. godine. Reznice 50 genotipova (46 autohtonih sorata te 'Cabernet sauvignon' i 'Rizling rajnski' kao osjetljive kontrole, a 'Solaris' i Vitis riparia kao otporne kontrole) posađene su u posude i uzgajane na vlastitom korijenu u poljskim uvjetima. Praćenje simptoma bolesti započelo je kad su mladice bile u stadiju od 10 razvijenih listova. Evaluacija pomoću modificiranog OIV deskriptora 452 (razina otpornosti listova) provedena je u četiri termina u dvotjednim intervalima tijekom svake vegetacije. Genotipovi su razvrstani u kvartile prema postotku listova sa simptomima bolesti. Genotip, termin evaluacije, kao i interakcija navedena dva faktora statistički se značajno razlikuju tijekom obje godine evaluacije. Iako su gotovo sve autohtone sorte postale potpuno zaražene do kraja vegetacije, kod nekih, kao što su 'Malvazija istarska', 'Teran', 'Trojišćina', 'Ranfol', bolest je sporije napredovala. Naredna istraživanja provodit će se s ciljem definiranja mogućih reakcija na kemijskoj razini koje su odgovorne za obrambeni mehanizam kod različitih genotipova.

'Belina starohrvatska’ je sorta koja se projektom revitalizacije autohtonih sorata vraća u proizvodne nasade Hrvatskog zagorja. Kako bi se omogućio komercijalni uzgoj potrebno je definirati ampelotehničke zahvate koji će osigurati kvalitetu grožđa. Cilj ovog istraživanja je bio utvrditi tijekom dvije godine utjecaj djelomične defolijacije na prinos i kvalitetu grožđa ove sorte. Rana defolijacija je provedena u dva termina: neposredno prije cvatnje i neposredno poslije cvatnje. Tretmani defolijacije u prvoj godini nisu značajno utjecali na kemijski sastav grožđa dok je tretman defolijacije prije cvatnje rezultirao nešto većim prinosom. Međutim kod kontrolne varijante došlo je do potpune zaraze grožđa sivom plijesni. U drugoj godini ponovljena je usporedba dvije varijante defolijacije, sa istim rezultatima, te je uz njih provedena i redukcija cvatova, koja također nije značajno utjecala na kemijske parametre grožđa.

Fenolni spojevi predstavljaju sekundarne biljne metabolite koji imaju vrlo važnu fiziološku i morfološku ulogu u rastu i reprodukciji biljke pružajući joj i zaštitu protiv patogena i predatora. Cilj ovoga istraživanja je dobiti pregled promjena u sastavu i sadržaju fenolnih spojeva odnosno flavonola, flavanola, hidroksicimetnih i hidroksibenzojevih kiselina prisutnih u listovima četiri različite crne sorte vinove loze. Ekstrakti su analizirani tekućinskom kromatografijom visoke djelotvornosti. Dobivenim rezultatima utvrđena je značajna varijabilnost u masenim udjelima fenolnih spojeva između sorata po pojedinim terminima uzorkovanja, kao i značajna varijabilnost u sadržaju fenolnih spojeva unutar iste sorte tijekom različitih termina uzorkovanja.

Zlatarica vrgorska je hrvatska autohtona sorta koja se uzgaja na području vinogorja Vrgorac i Neretva. Klonska selekcija Zlatarice vrgorske počela je 2018. godine provedbom masovne pozitivne selekcije na području vinogorja Vrgorac. Masovna pozitivna selekcija je provedena na 10 lokacija unutar vinogorja te su ukupno izdvojena 124 matična trsa. Masovna pozitivna selekcija obuhvatila je vizualnu ocjenu zdrastvenog stanja i ampelografsku evaluaciju (morfološke, fenološke i gospodarske kakakteristike). Na svakom matičnom trsu utvrđeni su broj grozdova i prirod (kg/trs) te osnovni kemijski pokazatelji kakvoće mošta (sadržaj šećera, ukupna kiselost, pH vrijednost). Srednje vrijednosti za sadržaj šećera u moštu kretale su se od 43, 67 do 96, 67 0Oe, dok je interval sadržaja ukupne kiselosti iznosio od 2, 75 do 7, 25 g/l. Raspon srednjih vrijednosti pH vrijednosti mošta iznosio je od 3, 2 do 3, 78. Utvrđene srednje vrijednosti priroda matičnih trsova kretale su se u rasponu od 0, 18 do 17, 98 kg/trs, a raspon srednjih vrijednosti broja grozdova po trsu je iznosio od 2 do 53 grozda. Rezultati su pokazali značajnu varijabilnost utvrđenih kvantitavnih i kvalitativnih svojstava. Spomenuto ukazuje na značajnu unutarsortnu varijabilnost populacije sorte Zlatarica vrgorska što je iznimno važno za nastavak postupka selekcije zdravstvenom i individualnom klonskom selekcijom.

Numerous grapevine breeding programs are carried out in the world with the aim of getting varieties resistant to fungal diseases. The basics are often native varieties in order to preserve the authenticity of a certain area. Croatia counts more than a hundred native varieties but there is no research on their downy mildew susceptibility, which is essential for further breeding. The aim of this study is to compare the two most widely used methods for estimating the susceptibility of grapevine varieties: in vivo (field trial) and in vitro using the leaf disk assay. The research was conducted on nine genotypes: seven native varieties, Cabernet Sauvignon and Vitis riparia. In vivo disease symptoms were monitored after flowering four times in two-week intervals, and the leaf disks were evaluated once on the leaves of different developmental stages (from the 1st to 7th leaf from the shoot tip). Significant differences in susceptibility between the examined genotypes were found using both methods. By using the in vivo method significant differences were noticed during the initial terms, while the differences were reduced later on suggesting that the rate of disease development is peculiar to the genotype. In vitro method showed, together with differences between the genotypes, significant differences between the leaves of different developmental stages. The highest level of correlation between the results of these two methods (r>0, 5) was determined between the third term in vivo and the 3rd to the 6th leaf (from the shoot tip) in in vitro conditions.

Cultivar Moslavac is considered as Croatian native cultivar. Because of its thin skin, soft berries and high vigour, the cultivar is susceptible to Botrytis, thus it should be planted on suitable vineyard sites and the canopy management operations should be used to control yield and vine microclimate. The aim of this work is to determine the effect of canopy management operations, early defoliation and grape thinning, on grape quality of cultivar Moslavac. The research was conducted in experimental vineyard in Sveti Urban (region Zagorje- Međimurje) with two treatments, control with none canopy management operations conducted and treatment with conducted early defoliation and grape thinning. Both operations were carried out at the same time, just after flowering. The defoliation was carried out removing all leaves in the fruiting zone, while grape thinning was carried out leaving just one grape bunch per shoot. After vérasion the ripening was monitored by measuring content of sugar and total acidity, while in full ripeness the yield and organic acids were determined. The higher content of sugars was determined at the treatment with early defoliation and grape thinning. Furthermore, the mentioned treatment did not show symptoms of Botrytis. There was no significant difference between treatments considering total acidity and the content of organic acids. It can be concluded that early defoliation and grape thinning had the greatest impact on sugar accumulation and very small impact on total acidity.

Sve veći značaj ekološke poljoprivredne proizvodnje i potreba smanjenja upotrebe pesticida polako postaje trend i u vinogradarskoj proizvodnji. U najrazvijenijim europskim vinogradarskim zemljama sorte vinove loze selekcionirane na otpornost na gljivične bolesti dobivaju na važnosti. Na Agronomskom fakultetu Sveučilišta u Zagrebu od 2005 do 2015.-te godine na Zavodu za Vinogradarstvo i vinarstvo provodila su se sustavna višegodišnja praćenja gospodarskih svojstava dvadesetak registriranih sorata tolerantnih na bolesti. Najbolje gospodarske pokazatelje u većini karakteristika kod bijelih sorata imala je sorta Bianca. Od ostalih sorata vrlo dobre otpornosti i dobrih gospodarskih svojstava svakako valja izdvojiti Panoniju, sortu selekcioniranu na vinogradarskom pokušalištu u Sremskim Karlovcima i sortu Johanniter selekcioniranu u vinogradarskom institutu u Freiburgu u Njemačkoj. Od crnih sorata najbolju kvalitetu vina imala je sorta Cabernet Cortis.

Na području Ozaljsko-vivodinskog vinogorja nalazi se očuvan veliki broj vinograda starijih pedeset pa i 100 godina. Sustavna identifikacija sortimenta toga područja nije nikada rađena a povijesnih zapisa nema. Cilja istraživanja bio je ampelografskim i genetičkim metodama utvrditi sortiment i pronaći unikatne genotipove i sorte na tome području. Od 61. uzorka za DNA analizu utvrđeno je 45 različitih genotipova. Od toga broja čak 18 unikatnih genotipova prisutnih samo na ovom području.

Context and purpose of the study – Croatia has rich grapevine genetic resources with more than 125 autochthonous varieties preserved. Coastal region of Croatia, Dalmatia, is well known for wine production based on autochthonous grapevine varieties. Nevertheless, only couple of these are widely cultivated and have greater economic importance. Grape seeds are sources of polyphenols which play an important role in organoleptic and nutritional value of grape and wine. Hence, the aim of this study was to evaluate the simple polyphenols from grape seeds in 20 rare autochthonous grapevine varieties. Material and methods – Samples were collected during two consecutive years (2011. and 2012.) from germplasm collection in Split (Dalmatia). Grape samples were constituted of five bunches of fully ripe grapes. Seeds were manually separated, freeze-dried, grounded and stored at a low temperature until analyses. Polyphenolic compounds were analysed using HPLC analysis. Results – Eight polyphenolic compounds, galic acid, monomeric flavan-3-ols (catechin, epicatechin, gallocatechin and epicatechin 3-O-gallate) and procyanidin dimers (B1, B2 and B4) were detected. According to the investigated polyphenolic compounds significant differences between investigated varieties were found. Gallic acid content ranged from 91.0 to 245.08 total monomeric flavan-3-ols from 619.2 to 13539.6 mg kg-1 and total procyanidin dimers from 975.3 to 4140.2 mg kg-1 of seed. Catechin (263.2 to 8124.2 mg kg-1 seed) was found as main monomeric flavan-3-ol, epicatechin 3-O-gallate, gallocatchin and epicatechin varied between 0-164.31, 37.19-155.07 and 277.5-5224.4 mg kg-1 seed, respectively. Procyanidin B2 (420.2 to 2207.8 mg kg-1 seed) was found as a main procyanidin dimer. Procyanidin B1 and B4 amount varied between 401.80-165.19 and 276, 7-1539.4 mg kg-1 seed, respectively. Gegić had lowest and varieties Plavac mali and Babić highest amount of all investigated polyphenolic compounds. This study presents the first evaluation of Croatian grapevine varieties by characterization of seed polyphenolic compounds and it shows huge variability among them. More detailed analysis of polyphenolic compounds in selected varieties are carry out in our further research activities.

Introduction: Croatia has very long viticultural history and more than 120 native grapevine cultivars. Among them there are cultivars that showed very good viticultural and enological potential, thus being in production for a long time. Due to the lack of clonal and sanitary selection in past, native cultivars in Croatia are having high level of intravarietal variability and virus infections. Modern viticulture requires stabile and uniform production characteristics and virus free planting material which can only be obtained through process of clonal selection. The clonal selection in Croatia started with cv. Škrlet in 2000 and was continued on other most important native cultivars from different wine regions. Currently, 12 cultivars are under the selection. Aim: The aim of this paper is to present the results of clonal selection in Croatia which was focused on improvement of productional characteristics of native grapevine cultivar, improvement of planting material quality and sanitary status. Materials and methods: The cultivars included in clonal selection are: Škrlet, Moslavac, Kraljevina, Graševina, Plavac mali, Maraština, Grk, Debit, Plavina, Pošip, Vugava and Žlahtina. The clonal selection was divided into three stages: 1) selection of initial material from old vineyards and virus testing (using ELISA) ; 2) establishment of experimental sites of vegetative progeny of virus free mother plants which were located depending on cultivar production region 3) final evaluation and registration of selected clones. Evaluation of clonal lines in stage two included evaluation of: yield level, cluster characteristics (compactness, mechanical composition, size and weight), chemical composition of must, vigor and susceptibility to pests. During final evaluation of selected clones in stage three, additional micorvinifications was performed including wine chemical and sensory analyses. Selected clones have also undergone analysis of grape aromatics (white cultivars) and polyphenols (red cultivars). Results: High level of intravarietal variability within populations of native cultivars allowed us to select sufficient number of virus free divergent clone candidates in first stage of selection despite the high level of virus infection detected. Vegetative progenies of all virus free mother vines were planted in second phase of selection, to preserve intravarietal variability for potential selection of new clones in future. Considering the importance of specific varieties, as well as divergency detected during process we decided to register different number of clones per variety: Plavac mali 5, Plavina 4, Pošip 4, Graševina 4, Kraljevina 4, Maraština 3, Škrlet 3, Vugava 2 and Debit 1. Three clones of cv. Škrlet are already registered while registration of others is planned during this year. Conclusion: The introduction of new clones will contribute to a sustainable grape and wine production, which can ensure better quality of wine. Moreover, it will contribute to production sustainability of native grapevine varieties in Croatia.

In spite of being a small country, Croatia presents an important source of grapevine biodiversity which can be interesting for wine industry and breeding. In last two decades our research activities are focused on preservation, genotyping and evaluation of production characteristics of native varieties. To define full potential of native varieties there is a need to define the level of their susceptibility to fungal diseases. The aim of this research was to define the level of susceptibility/resistance of Croatian grapevine varieties to downey mildew (Plasmopara viticola) using modified field screening method. Altogether 57 genotypes/varieties were included in the research: 52 Croatian native varieties, two susceptible international V. vinifera L. cultivars (Cabernet Sauvignon, Riesling), 2 resistant cultivars (Solaris, Regent) and 2 Vitis species (Vitis ripara, Vitis amurensis). Own-rooted cuttings were planted in drip irrigated pots in field conditions close to the production vineyard at experimental station “Jazbina”, Department of Viticulture and Enology, Faculty of Agriculture Zagreb. After initial growing of shoots to the certain stage the monitoring of disease symptoms was carried out according to OIV descriptor 452 (degree of resistance on leaves). Results showed small difference among native varieties and majority of them have very low and low level of resistance to downy mildew, as expected.

Introduction: Grapevine (Vitis vinifera L.) varieties are susceptible to fungal diseases like powdery mildew (Uncinula necator) and downy mildew (Plasmopara viticola) which are responsible for huge amount of pesticides used in grape production. Climatic conditions in Croatia are suitable for the development of fungal diseases, and that issue is even more severe in the northwestern part. Fungus resistant varieties are currently the only alternative for significant reduction of pesticides used in viticulture production. In order for them to become used for modern wine production, it is necessary to evaluate resistant varieties in different production conditions. Aim: The aim of this paper is to present the results of experiment conducted on twelve fungus resistant grape varieties in the conditions of the northwestern part of Croatia. Materials and methods: The varieties included in this experiment are Merzling, Phoenix, Staufer, Johanniter, Solaris, Regent, Cabernet Cortis, Bianca, Leon Millot, Monarch, Marechal Foch and Chancellor. As far as methods are concerned, the yield quality was determined by analyzing the chemical composition of must which includes the concentration of soluble solids and total acidity. The level of susceptibility to fungal diseases for each variety was determined. The microvinification and wine sensory analyses were performed. Secial focus was given to methyl alcohol content in the produced wines, organic acids composition of grape juice and polyphenolic composition of the berry skin and wine from red grape varieties. Results: The given results showed the level of susceptibility to fungal diseases comparable to other authors. The significant differences among investigated cultivars were noticed in all quality parameters evaluated. Based on these results, the resistant varieties Merzling, Phoenix, Staufer, Johanniter, Solaris, Regent and Cabernet Cortis were added to the list of recommended cultivars for wine production in the wine region West continental Croatia. Conclusion: All parameters determined among all the varieties in this experiment showed that some of them can be considered as a wine variety and become recommended in the northwestern part of Croatia. Even though most of varieties are not completely resistant to the fungal diseases in the given conditions, the application of fungicides could be reduced to minimum. They are specially interesting for organic wine production in this area.