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Phenotypic correlations were calculated and the levels of phenotypic integration of three congeneric species, annual Lamium purpureum and perennial Lamium album and Lamium maculatum, were estimated. Calculations were performed separately for different stages of development during transplantation under different density and light treatments. L. purpureum exhibited greater integration in comparison to the other two species before exposure to environmental treatments, as well as greater variability in phenotypic correlations in response to light and density. The perennial species possessed similar correlation patterns in comparison to annual L. purpureum, becoming more similar to L. purpureum at later stages of development. The effects of density and light intensity were dependent on the specific combination of factors, as well as on the species under study. Density effects in L. purpureum were also habitat- and population-specific. A greater difference in response to density treatments between habitats than between populations was detected. Overall, phenotypes become more integrated during ontogeny, while dissimilarities in phenotypic correlations among species and between populations were more related to ecological than to phylogenetic differences. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the structure of glandular trichomes and essential oil composition of Lamium purpureum L. (Lamiaceae) and to determine potential biological activities of its different extracts. The micromorphology and distribution of trichomes on vegetative plant parts were investigated using scanning electron microscopy (SEM). Two types of trichomes were identified: non-glandular (simple, uniseriate, multicellular) and glandular (both peltate and capitate). The essential oil of L. purpureum was isolated by hydrodistillation and analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The main compounds were trans-anethole (59.61%), fenchone (6.54%), α-pinene (6.14%) and β-pinene (4.98%). The total phenol and flavonoid contents of 10%, 30% and 50% ethanol extracts were determined spectrophotometrically. The free radical scavenging and reducing power activity of extracts were analyzed using the DPPH and ABTS radical scavenging methods, and the ferric reducing antioxidant power (FRAP) and total reducing power (TRP) assays. The 50% ethanolic extract exhibited the strongest antioxidative activity while the lowest was determined for the 10% ethanolic extract. Antifungal activity of L. purpureum hydroalcoholic extracts was evaluated against eight Aspergillus species by the microdilution method. Light microscopy (LM) demonstrated structural abnormalities of the tested Aspergilli. While the plant extracts did not exhibit fungicidal activity, morphophysiological changes (sporulation loss and depigmentation of conidial heads) were observed in all tested isolates. [ABSTRACT FROM AUTHOR]