The article discusses the use of biostimulant microalgae, known for their bioactive compounds. Understanding the positive impacts of biostimulants is essential for future applications. Research conducted in the Department of Plant Sciences at the Széchenyi István University has revealed that algae produce plant hormones and possess beneficial properties that influence the water, soil and plant systems. The effects of microalgae on various ornamental plants are being studied with a focus on improving root and general plant development. The methodology involves testing different algae extracts in ornamental plants in controlled environments. Data collection includes measuring plant height, leaf and bud numbers, chlorophyll content and other plant parameters through laboratory and destructive tests. The results indicate positive changes in plant parameters after treatments with biostimulant microalgae. In conclusion, biostimulant microalgae offer a promising and eco-friendly alternative to synthetic chemicals in the cultivation of ornamental plants. Continued research and innovation in this field is crucial to realise the full potential of biostimulants in sustainable agriculture.

Systematic studies on 70 MACC isolates previously identified as ‘Chlamydomonas’, a unicellular flagellate, were carried out based on partial 18S rRNA. The aim of this study was to determine the phylogenetic affiliations of Chlamydomonas strains in the MACC collection. The study found that most of the strains were not Chlamydomonas. Nine clusters of phylogenetically similar taxa were identified. The previous determinations were completed with their new phylogenetic affiliations (partly due to changes in green algae classification). Molecular data revealed that 3 of the 70 strains are from Arenicolinia, 14 are members of the phylogroup Stephanosphaerinia, 11 are Oogamochlamydinia, 1 is Chloromonadinia, 19 are Reinhardtinia, 2 are Polytominia, 9 are Scenedesmaceae, 5 are Moewusinia, and 6 are Chlorella. Clades were established by 18S rRNA similarity and p-distances. This study reveals the need to revise established culture collections whose isolates are solely identified with morphology.

Study on 37 MACC isolates previously identified as “Anabaena,” a freshwater filamentous heterocytous taxon, were carried out using the 16S rRNA. The study found that most of the strains were misidentified at genus level. Three clusters of phylogenetically and morphologically similar taxa were identified. The previous determinations were amended with their new taxonomic classifications (partly due to changes in cyanobacterial classification). Some morphological structures could not be found in the cultures (e.g. akinetes). Molecular data revealed that 6 of the 37 strains are Desmonostoc, 8 are members of the genus Nostoc, 19 strains bear genetic resemblance to the genus Trichormus and 4 strains remain unresolved. Clades were established by 16S rRNA similarity and p-distances. The goal of this study was to amend the strain designations in this collection. This study reveals the necessity to revisit established culture collections that originally used only morphological classifications for species identification.