Hop (Humulus lupulus L.) is used in the brewing industry as a source of compounds responsible for the bitterness, aroma, and preservative properties of beer. In this study, we used microsatellite markers to investigate genetic diversity and genetic differentiation of wild hop populations sampled in the northwestern part of Croatia. Analysis of 12 microsatellite loci revealed high diversity and weak population differentiation among wild hop populations. A total of 152 alleles were determined with an average of 12.67 alleles per locus. Observed heterozygosity ranged from 0.689 to 0.839 (average 0.767) and expected heterozygosity ranged from 0.725 to 0.789 (average 0.760). A total of 38 private alleles were detected. The data suggest that H. lupulus populations are not affected by recent bottlenecks. The degree of genetic differentiation among populations was low and not significant for most pairwise F_ST values, except for the pair of geographically most distant populations. The results did not indicate the existence of genetic structure among the sampled populations. The high genetic diversity and low differentiation among populations, combined with the absence of isolation by distance, indicate the existence of substantial gene flow among wild hop populations. Therefore, extensive sampling per population is clearly required to assess the genetic diversity of hop populations. Sampling strategies involving sampling across a large number of localities represented by only a few samples could lead to erroneous conclusions.

Allelopathy is a biological phenomenon of synthesizing and excreting compounds that can affect the growth of various organisms, i.e., plant species. The aim of this work was to investigate the possible allelopathic influence of aqueous extracts, obtained from plant species chia (Salvia hispanica L.), black cumin (Nigella sativa L.), wormwood (Artemisia absinthium L.), and nettle (Urtica dioica L.), on the seed germination growth and morphometric characteristics of pepper (Capsicum annuum L.), spinach (Spinacia oleracea L.) and lettuce (Lactuca sativa L.) seedlings in laboratory conditions. Pepper, spinach, and lettuce seedlings were treated with aqueous extracts of chia, nettle, wormwood, and black cumin of different concentrations (2.5, 5 and 10%, respectively). The aqueous extracts were prepared according to the method developed by Norsworthy and the qualitative and quantitative analysis of phenolic compounds in aqueous extracts were performed using ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). Phytochemical composition of chia aqueous extracts showed the highest content (above the 1 mg L⁻¹) of epicatechin, quinic acid, caffeic acid, esculetin and cinnamic acid in the comparison with others from the total of 19 detected chemical compounds. In aqueous extracts of black cumin, there were six compounds detected in content above 1 mg L⁻¹, i.e., epicatechin, quinic acid, caffeic acid, esculetin, cinnamic acid, and kaempferol. The same compounds were the most abundant in wormwood extracts, along with gallic acid. Epicatechin and esculetin were only two compounds detected in aqueous extract of nettle in concentration higher than 1 mg L⁻¹. According to the results of this study, only the treatment of spinach seeds with chia aqueous extract in concentration of 2.5% before germination stimulates the germination of spinach seeds, and wormwood herbs and chia extracts in concentrations of 2.5 and 5% stimulate the germination of lettuce seeds and the growth of hypocotyl and radicle length of developed seedlings. The treatment of pepper and lettuce seeds with aqueous extract of nettle in concentration of 10% completely inhibited seed germination.

Sweet violet (Viola odorata L.) blooms in continental climate conditions in early spring (March-April) with delicate flowers of attractive scent because of whi...

Lavandula species are one of the most popular aromatic plants in the world and have a high content of high-quality essential oil (EO). Although there are many species in this genus, only lavandin (Lavandula intermedia Emeric ex Loisel.) and lavender (L. angustifolia Mill.) are highly valued worldwide. The quality and yield of lavandin and lavender depend on genetic factors, environmental conditions and cultivation methods. Therefore, the aim of this paper is to research the effects of the application of biostimulant on the inflorescence yield and the quality of lavandin and lavender. The treatments used in this research consisted of a combination of different species (lavandin and lavender) and biostimulant (applied and unapplied). The research results show that all the research traits significantly depended on the used species and the applied biostimulant. The inflorescence yield, the content of total flavonoids, and the content of EO were higher in the lavandin species (477.3 g plant^-1, 17.21 mg CAE g^-1, 8.57 mL 100 g^-1, respectively) than in the lavender species (180.5 g plant^-1, 13.41 mg CAE g^-1, and 3.69 mL 100 g^-1, respectively). EOs of lavandin and lavender were rich in linalool and linalyl acetate. The use of biostimulators had a positive effect on the inflorescence yield and the content of essential oil. Furthermore, the applied biostimulant increased the linalool content in the essential oil of both researched species, i.e. it positively affected its quality.

Hren (Armoracia rusticana Ph. Garten) je višegodišnja povrtna kultura iz porodice kupusnjača (Brassicaceae). Korijen hrena sadrži visoku razinu vitamina C, minerale (kalij, magnezij, kalcij, fosfor, željezo), glukozinolate, glikozide, glukonasturcin, singrin, asparagin, glutamin, oksidaze i peroksidaze. Uzgaja se zbog zadebljanog podanka (rizoma), a jednogodišnji izdanci podanka koriste se za reprodukciju. U istraživanju provedenom na ekološkom gospodarstvu u okolici Varaždina korištena je autohtona čuvana sorta Ludbreški hren. Cilj istraživanja bio je utvrditi utjecaj organo mineralnih gnojiva dozvoljenih za primjenu u ekološkoj proizvodnji na prinos i sadržaj minerala u podanku hrena. Pokus je postavljen po slučajnom bloknom rasporedu u četiri repeticije i sljedećim varijantama gnojidbe sa organo mineralnim gnojivima dobrog biostimulativnog učinka (Biotech NPK 3:10:5 S+2 MgO u kombinaciji s Grena Biosprint Calcio NPK 9:1:1; Grena Biobase NPK 3:8:8; Grena life NPK 4:6:10 S+2 MgO). Promatrajući sve dobivene rezultate uglavnom je utvrđen pozitivan učinak organo mineralnih gnojiva na istraživane parametre.