1. Magnetna poravnava sviloprejk med prehranjevanjem : diplomsko deloTjaša Irgolič, 2025, diplomsko delo Opis: Sviloprejke (Bombyx mori L.) so nočni metulji, katerih ličinke že tisočletja vzgajajo za pridelavo svile. Na njihovo vedenje in razvoj vplivajo mnogi okoljski dejavniki, kot so svetloba, temperatura in vlaga. Poleg teh, utegnejo imeti na sviloprejke vpliv tudi diskretnejši dejavniki, kot je geomagnetizem. Geomagnetne silnice namreč povzročajo pojav magnetne poravnave, ki je opredeljena kot usmerjanje telesa živali glede na geomagnetno polje, običajno vzporedno z magnetnimi silnicami (S–J) ali pravokotno nanje (V–Z). Pojav je bil potrjen že pri mnogih živalskih vrstah, pri sviloprejkah pa še ni bil preučevan, čeprav utegne predstavljati pomembno informacijo za svilogojce. V raziskavi smo zato želeli preveriti, ali sviloprejke med hranjenjem kažejo znake magnetne poravnave. V raziskavo je bilo vključenih 100 gosenic sviloprejke v fazi po tretji levitvi , razdeljenih v štiri skupine po 25 živali. Njihov položaj smo s pomočjo kamer opazovali trikrat dnevno, vsakih šest ur, s prvim jutranjim opazovanjem ob 7:00. Rezultati so pokazali, da so se sviloprejke po tretji levitvi v prvih petih dneh eksperimenta (dan < 5) kazale značilno poravnavo v smeri sever–jug (p ≤ 0,05) ta je bila najbolj opazna v jutranjem in popoldanskem času. V večernem času magnetne poravnave ni bilo zaznati (p ≥ 0,05). Prav tako po petem dnevu (dan > 5) in po četrti levitvi, ko so začele iskati primeren prostor za zapredanje kokonov, magnetne poravnave nismo več zaznali (p ≥ 0,05). Ugotovili smo, da sviloprejke izkazujejo magnetno poravnavo, vendar je ta časovno omejena tako na del dneva kot tudi na obdobje v fazi razvoja, tj. pred začetkom faze zapredanja. Razumevanje vpliva geomagnetizma in upoštevanje naravnih vzorcev orientacije sviloprejk, kot je magnetna poravnava, lahko prispevajo k učinkovitejšemu hranjenju in posledično boljši rasti ličink sviloprejk.
Ključne besede: bela murva, Bombyx mori L., magnetna poravnava, Morus alba L., sviloprejka
Objavljeno v DKUM: 14.10.2025; Ogledov: 0; Prenosov: 13
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2. Local climate and cultivation practice shape total protein and phenolic content of mulberry (morus sp.) leaves in sub-mediterranean and sub-pannonian regions of SloveniaŠpela Jelen, Martin Kozmos, Jan Senekovič, Danijel Ivajnšič, Silvia Cappellozza, Andreja Urbanek Krajnc, 2025, izvirni znanstveni članek Opis: Mulberry (Morus sp.) trees, traditionally cultivated for their leaves used in sericulture, have recently gained recognition for their adaptability and valuable ecosystem services. The biochemical composition of mulberry leaves varies both qualitatively and quantitatively, depending on genotype, environmental conditions, and cultivation practices. This study aimed to (1) identify differences in old local white (M. alba L.) and black mulberry (M. nigra L.) leaves, (2) perform a chemotype analysis of monitored local varieties, and (3) evaluate the influence of selected bioclimatic factors and pruning practices on the biochemical composition of leaves of white mulberry trees across Slovenian mesoregions. Black mulberry exhibited a higher phenolic content, particularly caffeoylquinic acid derivatives (16.05 mg/g dry weight (DW)), while white mulberry contained more quercetin glycosides (6.04 mg/g DW). Ward’s clustering identified three chemotypes, two of which had elevated protein and hydroxycinnamic acid levels, making them particularly suitable for silkworm feeding. Considering pruning practices of white mulberries, we determined significantly increased protein contents in yearly pruned trees (187.24 mg/g DW). Principal component analysis revealed interactions between bioclimatic, morphological, and biochemical factors, distinctly separating mulberries from the Sub-Mediterranean and Sub-Pannonian macroregions. White mulberries from Sub-Pannonian regions accumulated more caffeoylquinic acids in leaves under lower precipitation and total insolation, while those from Sub-Mediterranean regions exhibited higher kaempferol derivatives due to photo-thermal stress. These findings highlight the influence of climate and pruning on mulberry biochemical diversity and adaptation.
Ključne besede: mulberry, Morus alba, Morus nigra, local genetic resources, phenolics, protein, climatic effect, metabolite screening, pruning
Objavljeno v DKUM: 07.10.2025; Ogledov: 0; Prenosov: 5
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3. Pomen fotosinteznih pigmentov in antioksidantov v solati pri obrambi pred polži : magistrsko deloTimotej Gabriel Horvat, 2025, magistrsko delo Opis: Solata (Lactuca sativa L.) sodi med gospodarsko pomembnejše zelenjadnice, njeno pridelavo ogrožajo številni rastlinojedi škodljivci, med katerimi so tudi polži. Cilj magistrskega dela je bil raziskati odziv antioksidativnega sistema solate na oksidativni stres, ki nastane ob napadu dveh različnih vrst polžev. Askorbatno-glutationski cikel in ksantofilni cikel predstavljata ključna antioksidativna mehanizma v rastlinah, spremembe v vsebnosti njunih komponent (askorbat, glutation in fotosintezni pigmenti) lahko služijo kot pokazatelji nivoja oksidativnega stresa. V poskusu smo rastline v kontroliranih pogojih rastlinjaka ločeno izpostavili dvema vrstama polžev mrežasti slinar (Deroceras reticulatum) in španski lazar (Arion vulgaris), pri čemer smo spremljali spremembe v vsebnosti askorbata, glutationa ter fotosinteznih pigmentov v primerjavi s kontrolno skupino. Napad polžev je povzročil pomembne, statistično značilno različne spremembe v vsebnostih antioksidantov. Napad lazarja je povzročil povečanje vsebnosti glutationa in askorbata v listih ter njuno zmanjšanje v koreninah, medtem ko je napad slinarja povzročil zmanjšanje vsebnosti obeh antioksidantov tako v listih kot v koreninah. Spremembe so bile vidne tudi pri fotosinteznih pigmentih – povečala se je vsebnost skupnih karotenoidov, anteraksantina in zeaksantina, zmanjšala pa vsebnost skupnih klorofilov in violaksantina. Rezultati kažejo, da napad polžev sproži aktivacijo antioksidativnih mehanizmov, kar prispeva k boljšemu razumevanju sistemske obrambne prilagoditve rastlin ob napadu rastlinojedih škodljivcev.
Ključne besede: solata (Lactuca sativa L.), mrežasti slinar (Deroceras reticulatum), španski lazar (Arion vulgaris), fotosintezni pigmenti, antioksidanti
Objavljeno v DKUM: 09.09.2025; Ogledov: 0; Prenosov: 17
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4. Analiza vsebnosti skupnih fenolov v skorji različnih genotipov murv (Morus sp.) : diplomsko deloEvelyn Vuk, 2025, diplomsko delo Opis: V okviru diplomskega dela je bila analizirana vsebnost skupnih fenolov v skorji enoletnih poganjkov različnih genotipov murv (Morus sp.), z namenom ugotavljanja razlik glede na genotip in vrsto murv, vključenih v raziskavo. Dodatno je bila izvedena primerjava vsebnosti skupnih fenolov med skorjo in listi murv. V raziskavo so bile vključene referenčne svilogojske sorte, lokalna slovenska genotipa bele murve (Morus alba) ter križanec med belo in rdečo murvo (M. alba × M. rubra). Enoletni poganjki murv so bili vzorčeni v dveh terminih, skorja je bila po lupljenju liofilizirana in zmleta v fini prah. Skupni fenoli v skorji so bili analizirani po metodi Folin-Ciocalteu. Rezultati analize so pokazali statistično značilne razlike v vsebnosti skupnih fenolov med genotipi murv. Najvišja vsebnost skupnih fenolov v skorji je bila ugotovljena pri križancu bele in rdeče murve (5,14 ± 0,004 mg GAE/g SS), najnižja pa pri referenčni svilogojski sorti 'Kokusou' (4,60 ± 0,08 mg GAE/g SS). Prav tako je bilo ugotovljeno, da se vsebnost skupnih fenolov v skorji murv statistično značilno razlikuje med vrstama (p = 0,032). Primerjava skupnih fenolov med skorjo in listi je potrdila hipotezo, da je vsebnost skupnih fenolov v skorji nižja kot v listih. Rezultati so pokazali, da na vsebnost fenolnih spojin vplivajo tako genetski dejavniki kot tudi morfološko tkivo, kar poudarja pomen posameznih delov murv, ustreznega vzorčenja in izbire analitske metode pri nadaljnjih raziskavah bioaktivnih spojin v murvah.
Ključne besede: Morus sp., murva, kemotipske razlike, skorja, skupni fenoli
Objavljeno v DKUM: 03.09.2025; Ogledov: 0; Prenosov: 26
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5. Composition of proteins and phenolics in the leaves of differente mulberry species (Morus alba L., M. alba x rubra, M. australis Poir., M. nigra L.)Špela Jelen, Andreja Urbanek Krajnc, 2023, izvirni znanstveni članek Opis: The leaves of the mulberry (Morus sp.) have a variety of medicinal, culinary, industrial and agricultural applications. In our study, we compared the protein and phenolic contents of different mulberry species (Morus alba L., M. alba × rubra, M. australis Poir., M. nigra L.) from the mulberry germplasm collection to determine species-specific differences. The possibility of using mulberries as animal feed and for pharmacological purposes was reviewed. Total phenols of all genotypes were analysed using the Folin-Ciocalteu method, while total protein content was determined using the Lowry's method. The individual phenols were analysed by high-performance liquid chromatography with UV/VIS detection. The total protein content ranged from 162.03 mg BSA/g DW (M. australis) to 239.42 mg BSA/g DW (M. alba). Significantly higher contents of total proteins were determined in the leaves of M. alba. The highest mean concentrations of total phenols (21.51 mg GAE /g DW), chlorogenic acid (18.05 mg/g DW), 4-caffeoylquinic acid (4.36 mg/g DW), 5-p-coumaroylquinic acid (2.01 mg/g DW), quercetin glycoside (0.74 mg/g DW) and kaempferol acetyl hexoside (4.42 mg/g DW) were determined in M. alba × rubra and M. nigra. In contrast, white mulberry (M.
alba) genotypes contained on average the most rutin (2.63 mg/g DW) and quercetin-malonyl-hexoside (1.59 mg/g DW). It can be concluded that the leaves of the white mulberry are best suited as animal feed due to their high protein content, while the black mulberry and the hybrid M. alba × rubra have pharmacological potential due to their high phenolic content.
Ključne besede: Morus sp., leaves, proteins, phenolic acids, flavonoids
Objavljeno v DKUM: 23.04.2025; Ogledov: 0; Prenosov: 3
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6. Copper sulfate elicitation effect on biomass production, phenolic compounds accumulation, and antioxidant activity of Morus nigra L. stem node cultureJan Senekovič, Špela Jelen, Andreja Urbanek Krajnc, 2025, izvirni znanstveni članek Opis: Phenolic compounds are strong antioxidant and antibacterial agents with great pharmacological, medicinal, nutritional, and industrial value. The potential of Morus nigra in stem node culture was investigated for the production of phenolic compounds and their elicitation with CuSO4. Individual phenolic compounds in the samples were identified and quantified by using HPLC-PDA and HPLC-MS methods, while the content of total phenolic compounds, the content of total flavonoids, and the antioxidant activity of methanolic extracts were evaluated spectrophotometrically. The highest fresh and dry weights were obtained in plantlets treated with 0.5 mM CuSO4 for 42 days. The highest total phenolic content, total flavonoid content, and antioxidant activity of the extracts were determined in stem node cultures treated with 3 mM CuSO4 for 42 days. Under the latter conditions, the predominant representatives of the caffeoylquinic acids, p-coumaric acid derivatives, kaempferol derivatives, and quercetin derivatives also achieved the highest content. The most abundant phenolic compound in all samples was the chlorogenic acid. The nodal culture of M. nigra elicited with CuSO4 could potentially be used for the industrial production of phenolic compounds, especially caffeoylquinic acids. Moreover, considering the biochemical response to CuSO4 treatment and the ability to tolerate and accumulate copper, the potential application of M. nigra in phytoremediation is also highlighted.
Ključne besede: antioxidative potential, black mulberry, copper stress, elicitation of phenolics, flavonoids, in vitro culture, nodal culture, phenolic acids
Objavljeno v DKUM: 25.03.2025; Ogledov: 0; Prenosov: 15
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7. Identification and content of astaxanthin and its esters from microalgae Haematococcus pluvialis by HPLC-DAD and LC-QTOF-MS after extraction with various solventsBiljana Todorović, Jaša Veno Grujić, Andreja Urbanek Krajnc, Roman Kranvogl, Jana Ambrožič-Dolinšek, 2021, izvirni znanstveni članek Opis: Haematococcus pluvialis, a unicellular green microalga that produces a secondary metabolite under stress conditions, bears one of the most potent antioxidants, namely xanthophyll astaxanthin. The aim of our study was to determine the content of astaxanthin and its esterified forms using three different solvents—methyl tert-butyl ether (MTBE), hexane isopropanol (HEX -IPA) and acetone (ACE)—and to identify them by using high performance liquid chromatography coupled with diode array detection and the quadrupole time-of-flight mass spectrometry (HPLC-DAD and LC-QTOF-MS) technique. We identified eleven astaxanthin monoesters, which accounted for 78.8% of the total astaxanthin pool, six astaxanthin diesters (20.5% of total), while free astaxanthin represented the smallest fraction (0.7%). Astaxanthin monoesters (C16:2, C16:1, C16:0), which were the major bioactive compounds in the H. pluvialis samples studied, ranged from 10.2 to 11.8 mg g−1 DW. Astaxanthin diesters (C18:4/C18:3, C18:1/C18:3) were detected in the range between 2.3 and 2.6 mg g−1 DW. All three solvents were found to be effective for extraction, but MTBE and hexane-isopropanol extracted the greatest amount of free bioactive astaxanthin. Furthermore, MTBE extracted more low-chain astaxanthin monoesters (C16), and hexane-isopropanol extracted more long-chain monoesters (C18 and above) and more diesters. We can conclude that MTBE is the solvent of choice for the extraction of monoesters and hexane-isopropanol for diesters.
Ključne besede: astaxanthin diesters, astaxanthin monoesters, carotenoids, Hematococcus pluvialis, astaxanthin diesters, solvent extraction
Objavljeno v DKUM: 22.11.2024; Ogledov: 0; Prenosov: 26
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8. Editorial : Phytochemicals in ornamental plants: Synthesis, nutraceutical prospects and applied focus—Women in plant science seriesValentina Schmitzer, Wee Sim Choo, Andreja Urbanek Krajnc, 2022, predgovor, uvodnik, spremna beseda Ključne besede: ornamental plants, Brassica oleracea, Skimmia anquetilia, Clitoria ternatea, phytochemicals, editorial
Objavljeno v DKUM: 04.07.2024; Ogledov: 85; Prenosov: 15
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9. Ocena stopnje škodljivosti in razširjenosti tujerodnih rastlinskih vrst v kmetijski pridelavi Slovenije za obdobje 2000-2022Mario Lešnik, Andrej Paušič, 2024 Opis: V obdobju 2000-2022 smo izvajali spremljanje kmetijskih površin in nekaterih ob agrarnih habitatov po vsem ozemlju Slovenije glede pojavnosti tujerodnih invazivnih rastlin. Tujerodne rastline smo evidentirali in podali ocene o velikosti populacij. Hkrati smo izvedli oceno škodljivosti invazivnih rastlin za kmetijsko pridelavo. Obravnavali smo invazivne rastlinske vrste, ki jih pogosto omenjajo v mednarodno priznanih bazah invazivnih v geografskih območjih, ki so nam primerljiva po klimatskih in pedoloških značilnostih in po značilnostih kmetijskih pridelovalnih sistemov. V uvodu je predstavljena metodologija ocenjevanja škodljivosti vrst. Za večino vrst je škodljivost možno precej realno oceniti. Velika neznanka so klimatske spremembe, predvsem minimalne zimske temperature, ki odločajo o dolgoročnem ohranjanju tujerodnih večletnih rastlin. Med njimi je veliko takšnih, ki preraščajo vegetacijo, če uspejo preživeti zimo predstavljajo nevarne invazivke z ekosistemsko škodljivostjo. Pomembno vlogo bo imela tudi dostopnost herbicidov. Če se bo zmanjšala, bodo nekatere nove vrste pridobile na pomenu, ker jih ne bomo mogli učinkovito kemično zatirati. Vse več vrst je ekološko problematičnih tudi zato, ker so vmesni gostitelji novih tujerodnih povzročiteljev bolezni in škodljivcev, ki ogrožajo gojene rastline.
Ključne besede: alohtone vrste, škodljivost, kmetijstvo, Slovenija, invazivne rastlinske vrste
Objavljeno v DKUM: 06.05.2024; Ogledov: 332; Prenosov: 300
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10. The Darker the better : Identification of chemotype profile in soroses of local and introduced mulberry varieties with respect to the colour typeAndreja Urbanek Krajnc, Jan Senekovič, Silvia Cappellozza, Maja Mikulič Petkovšek, 2023, izvirni znanstveni članek Opis: Mulberries are the "essence of the past", the so-called Proust effect, for the inhabitants of the sericultural regions who enthusiastically remember feeding silkworms with mulberry leaves and picking the different coloured fruits that were their favourite sweets in childhood. To determine the chemistry behind the colour and taste of mulberry soroses, the main metabolites of the local and introduced varieties were studied. The soroses were classified into five different colour types and the size parameters were determined. The main sugars identified were glucose and fructose, while the predominant organic acids were citric and malic acids, which were highest in the darker varieties, and fumaric and tartaric acids, which were highest in the lighter varieties. A total of 42 phenolic compounds were identified. The predominant phenolic acid was chlorogenic acid, followed by other caffeoylquinic acids and coumaroylquinic acids. The predominant anthocyanins were cyanidin-3-glucoside and cyanidin-3-rutinoside. According to PCA analysis, the colour types showed a clear chemotype character. The sweet taste of the yellowish-white soroses was defined by 49% fructose, followed by 45% glucose and 6% organic acids. The sour character of the black genotypes was characterised by a lower sugar and higher (11%) organic acid content. The colour- and species-dependent effect was observed in the proportion of caffeoylquinic acids and quercetin glycosides, which decreased with increasing colour intensity from 60% of the total to 7%, and from 17% to 1%, respectively. An upward trend was observed for flavanols (5% to 29%) and anthocyanins, which accounted for 62% of the total phenolics in black varieties. This article gives an insight into the metabolite composition of mulberry soroses as the sweets of choice between light and sweet and dark and sour.
Ključne besede: mulberry soroses, sugars, organic acids, phenolics, anthocyannins
Objavljeno v DKUM: 20.02.2024; Ogledov: 380; Prenosov: 37
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