Fungi colonizing dead leaves of herbs

The material was collected from the Botanical Garden and the Collegium Medicum Medicinal Plant Garden of the Jagiellonian University in Krakow. The investigated species were: lemon balm (Mellisa officinalis L.), common lavender (Lavendula angustifolia Mill.), horsemint (Mentha longifolia L.), sage (Salvia officinalis L.), sweet basil (Ocimum basilicum L.), and wild marjoram (Origanum vulgare L.). The aim of the investigation was to identify fungi causing the death of leaf tissues of herbs from the mint family Lamiaceae. In mycological investigations, 180 fragments of each plant leaves (1,080 dead leaf fragments in total) were placed in a 2% PDA medium. Over 970 colonies of fungi belonging to 48 species were isolated from the dead leaf tissues of the six herb species. Alternaria alternata (toxin-producing), Epicoccum nigrum and Sordaria fimicola were the most frequently isolated. The largest numbers of colonies and species of fungi were isolated from horsemint, while the lowest numbers were from wild marjoram leaves. It was shown that the death of leaves of selected herb species from the Lamiaceae family was caused by various fungi. The results of the mycological analysis confirmed the diversity of species colonizing the leaves of the herbs.