Fungi colonizing and damaging different parts of some medicinal plants
Introduction: Many fungal species infect medicinal plants during their cultivation, causing great damage to the yield and decreasing the quality of raw material. Objective: Due to the increase in contamination of raw material and the damage caused by pathogenic fungi, the main species of medicinal plants cultivated in Poland were subject to the investigation. Methods: In 2012–2014, an experiment was conducted on eight medicinal plant species breeding nurseries grown in the field in Plewiska. The following species and cultivars were investigated: lemon balm, peppermint, St. John’s wort cv. ‘Topaz’, lovage cv. ‘Amor’, valerian cv. ‘Polka’, caraway cv. ‘Kończewicki’, sweet basil cv. ‘Wala’, marjoram cv. ‘Miraż’. Results: Fourteen species of eleven genera of pathogenic fungi were isolated from the investigated medicinal plants: Fusarium avenaceum, F. culmorum, F. equiseti, F. oxysporum, Botrytis cinerea, Alternaria alternata, Cladosporium sp., Rhizoctonia solani, Septoria sp., Boeremia exiqua, Golovinomyces cichoracearum, Penicillium sp., Ramularia sp., and Sclerotinia sclerotiorum. The most severe infection was caused by Fusarium sp. and Botrytis cinerea. Also Cladosporium sp. (4 species), A. alternata and Septoria sp. (3 species) infected plant tissue. Leaves and stems were the most infected parts of the tested plants. Lemon balm, lovage and valerian were the most infected species, while marjoram was infected only with Fusarium sp.