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Polyphenols are secondary plant metabolites and important organic compounds present in grapes, must and wine. The importance of polyphenolic compounds present in grapes is mainly related to the quality of the wine. Those compounds affect the colour, taste, astringency, bitterness, and potential of wine aging. Therefore, the aim of this research was to determine and compare quantitative and qualitative changes in low molecular weight polyphenol content of 11 red grapevine varieties during ripening. Samples were collected periodically from the beginning of vérasion to the technological maturity. The polyphenolic compounds were analysed with high performance liquid chromatography (HPLC) with prior lyophilization and extraction. Based on the obtained results, changes in the composition and content of researched groups of polyphenolic compounds during maturation were determined., Polifenoli su sekundarni biljni metaboliti te važni organski spojevi prisutni u grožđu, moštu i vinu. Važnost polifenolnih spojeva prisutnih u grožđu uglavnom je vezana uz kakvoću vina obzirom da utječu na boju, okus, astringenciju, gorčinu te potencijal starenja vina. Cilj ovog rada je utvrditi i usporediti kvantitativne i kvalitativne promjene sadržaja polifenola male molekulske mase u kožici grožđa 11 crnih sorata vinove loze tijekom dozrijevanja grožđa. Uzorci su prikupljani periodično od početka šare do tehnološke zrelosti. Sadržaj polifenola u kožici boba utvrđen je tekućinskom kromatografijom visoke djelotvornosti (HPLC) uz prethodnu liofilizaciju i ekstrakciju. Temeljem dobivenih rezultata utvrđene su promjene sastava i sadržaja pojedinih grupa polifenolnih spojeva tijekom dozrijevanja.

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.

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.

ERASMUS+ KA2 projekt „Trainers for Plant Protection in Organic Farmings- TOPPlant provodi se od 2020. godine. Radi se o projektu kojim se razvijaju suradnička partnerstva u području strukovnog obrazovanja i osposobljavanja te obrazovanja odraslih. Projekt provodi pet partnera iz četiri zemlje, Austrije, Slovenije, Mađarske i Hrvatske. Projekt ima za cilj razviti nastavni plan i program za edukatore o zaštiti bija u ekološkoj proizvodnji te pripremiti nastavne materijale koji omogućavaju uspješno savladavanje programa. U skladu s postavljenim ciljevima, u sklopu projekta pripremljen je metodološki nastavni plan i program za edukaciju o zaštiti bilja u ekološkoj proizvodnji. Radi se o univerzalnom metodološkom planu i programu kojeg mogu u svojoj edukacijskoj ponudi koristiti svi koji provode edukaciju odraslih kao univerzalni edukacijski program za zaštitu bilja u ekološkoj proizvodnji. Nastavni plan je namijenjen osobama s edukacijom iz područja poljoprivrede na razini 5 ili osobama s drugom vrstom edukacije na istoj ili nižim razinama ako imaju najmanje pet godina iskustva u ekološkoj poljoprivredi. Nakon završenog programa predviđa se da će polaznici steći kvalifikacijsku rainu 5. Nastavni program podijeljen je u pet cjelina (1) Osnovna načela modela učenja sa sudjelovanjem zasnovanog na eksperimentalnom učenju ; (2) Opća načela ekološke poljoprivrede i utjecaj na štetne organizme ; (3) Metode i alati za suzbijanje štetnika ; (4) Metode i alati za suzbijanje uzročnika bolestii i (5) Metode i alati za suzbijanje korova. Za svaku su nastavnu cjelinu predviđeni ishodi učenja, predviđen je detaljan sadržaj nastavnih jedinica i njihova povezanost s ishodima učenja, predviđeno je vrijeme trajanja, nastavne metode, obaveze polaznika i propisana literature. Temeljem nastavnog plana pripremljen je priručnik za edukaciju o ekološkoj zaštiti bilja. Priručnik je podijeljen u istih pet cjelina, ilustriran je shemama, praktičnim primjerima i slikama. Na kraju svakog podpoglavlja je test uz pomoć kojeg polaznici mogu provjeriti stečeno znanje. Odličan je alat za edukatore koji će sudjelovati u edukaciji organiziranoj u sklopu projekta, ali i za sve zainteresirane za zaštitu bilja u ekološkoj proizvodnji kao i za studente. Smjernice za zaštitu bilja u ekološkoj proizvodnji odabranih kultura namijenjene su proizvođačima i one pružaju specifične upute o zaštiti odabranih kultura od najvažnijih štetnih organizama. Pripremljene su smjernice za zaštitu vinove loze, jabuke, krumpira, luka i paprika, kultura koje su od velike važnosti u zemljama koje provode projekt. Sadržaj priručnika je pripremljen također kao interaktivni alat za e-učenje uz pomoć kojeg polaznici mogu samostalno savladati nastavne sadržaje, provjeriti znanje i dobiti certifikat o savladavanju programa on-line. Svi materijali pripremljeni su na pet jezika, engleskom, hrvatskom, njemačkom, slovenskom i mađarskom. Materijali su dostupni na portalu https://topplantportal.eu/ i može im se pristupiti slobodno uz prethodnu registraciju.

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.

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.

Polifenoli su sekundarni biljni metaboliti te važni organski spojevi prisutni u grožđu, moštu i vinu. Važnost polifenolnih spojeva prisutnih u grožđu uglavnom je vezana uz kakvoću vina obzirom da utječu na boju, okus, astringenciju, gorčinu te potencijal starenja vina. Cilj ovog rada je utvrditi i usporediti kvantitativne i kvalitativne promjene sadržaja polifenola male molekulske mase u kožici grožđa 11 crnih sorata vinove loze tijekom dozrijevanja grožđa. Uzorci su prikupljani periodično od početka šare do tehnološke zrelosti. Sadržaj polifenola u kožici boba utvrđen je tekućinskom kromatografijom visoke djelotvornosti (HPLC) uz prethodnu liofilizaciju i ekstrakciju. Temeljem dobivenih rezultata utvrđene su promjene sastava i sadržaja pojedinih grupa polifenolnih spojeva tijekom dozrijevanja.

The research of sanitary status and virus presence was conducted on three native Croatian grapevine varieties (Kujudžuša bijela, Zlatarica vrgorska and Trnjak crni) that are grown in Dalmatia region. The investigation was done on 492 vines from 31 vineyards. Vines were tested by ELISA (Enzyme-Linked Immunosorbent Assay) on four main economic viruses: arabis mosaic virus (ArMV), grapevine fanleaf virus (GFLV), grapevine leafroll-associated virus 1 and 3 (GLRaV–1, GLRaV-3) as a first step in clonal selection of these rare native grapevine varieties. Altogether, 40 vines were free of all tested viruses. The research confirms high rate of virus infection and eroded sanitary status of all investigated varieties. The above indicates necessity of implementation clonal and sanitary selection programme.

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.

Defolijacija je ampelotehnički zahvat kojim se uklanjaju listovi vinove loze. Ovaj zahvat može se koristiti u različitim fenofazama razvoja vinove loze. Ovisno o periodu obavljanja, defolijacija može biti rana ili kasna. Rana defolijacija podrazumijeva period uklanjanje lišća prije cvatnje do zametanja bobica, dok se kasna defolijacija obavlja početkom šare bobica. U ovom radu su istraživana tri termina defolijacije te njihov utjecaj na kemijski sastav grožđa sorte Graševina. Defolijacija nakon cvatnje rezultirala je najvišim sadržajem ukupnih polifenola, kod defolijacije u zoni grožđa početkom šare utvrđen je najviši sadržaj šećera i ukupnih kiselina, dok je defolijacija iznad zone grožđa početkom šare sveobuhvatno imala statistički najmanje značajan utjecaj na kemijski sastav grožđa.

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.

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.

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.

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.

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.