Fungi infected the Zinnia elegans Jacq. concerning susceptibility of cultivars to selected pathogens
Irena Kiecana, Elżbieta Mielniczuk

Abstract. Zinnia elegans is an annual plant recommended for cultivation for cut flowers as well as flowerbeds. This ornamental plant can be infected by: viruses, bacteria, phytoplasms and by a number of fungi species. Presented studies were conducted in 2006 in three localities of the Lublin region: in the vicinity of Zamość, near Krasnystaw and near Opole Lubelskie. Those studies included three cultivars of Zinnia elegans Jacq.: Golden Dawn, Lawa, Scarlet Flame as well as the mixed material of the cultivars belonging to the dahlia group. Six weeks after the sowing, the seedling’s healthiness was assessed. The proportion of seedlings with disease symptoms ranged from 7% to 44%. The main cause of root infection at the seedling stage proved to be the species of F. equiseti and S. sclerotiorum. Considerable amounts of B. cinerea and F. culmorum and A. alternata were also detected from diseased seedlings. Studies on the susceptibility of analyzed cultivars and the mixed material of elegans zinnia to infection by B. cinerea and F. avenaceum, F. culmorum and F. equiseti were conducted in a growth chamber. Results obtained from this experiment confirmed considerable harmfulness of the species B. cinera and F. equiseti towards the seedlings of elegans zinnia, which can be reduced introducing less susceptible varieties to the cultivation. However, none of the studied varieties of elegans zinnia, only its mixed material, showed such properties.

Key words: healthiness,seedlings, pathogenicity, Fusarium spp., Botrytis cinerea, Sclerotinia sclerotiorum