Submitted to: Plant Disease
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/26/2008
Publication Date: 6/1/2008
Citation: Kolomiets, T.M., Mukhina, Z.M., Kassanelly, D., Matveeva, T., Bogomaz, D., Berner, D.K. 2008. First report of leaf spot caused by a Periconia igniaria on yellow starthistle in Russia. Plant Disease. 92:983. Interpretive Summary: Yellow starthistle is a target of biological control efforts in the U.S. Diseased yellow starthistle plants were found around Taman, in the Krasnodar region of Russia. The fungus Periconia igniaria was determined to cause the disease. In the laboratory, it was found that this fungus readily caused disease and significant damage on yellow starthistle, and that this particular fungus has potential as a biological control for yellow starthistle in the U.S.
Technical Abstract: In the summer of 2006, several hundred diseased yellow starthistle (YST) plants were found around Taman, in the Krasnodar region of Russia. Symptoms of the disease were yellow-pink water-soaked leaf spots. Diseased leaves were collected, air-dried, and sent to the Russian State collection of phytopathogenic organisms in the All Russia Institute of Phytopathology (ARIP). The fungus isolated from the diseased leaves conformed to the description of Periconia igniaria E.W. Mason et M.B. Ellis (Teleomorph: Didymosphaeria igniaria C. Booth). Fifteen YST plants were inoculated with an aqueous suspension of P.igniaria conidia at a concentration 5 ×106 conidia/ml. Disease on plant leaves was observed on all plants 3-4 weeks after inoculation beginning when the plants started to bolt. When the plants reached flowering stage, diffused yellow-pink spots were observed on stems and inflorescences, and there was complete destruction of flowers and flower parts. Diseased leaves from each plant were surface disinfested and put on potato-saccharose nutrition medium. Periconia igniaria was re-isolated from 3-5 leaves of each plant. Periconia igniaria was also re-isolated from 10 - 15 inflorescences and stems that developed from inoculated rosettes. This seemed to indicate that the fungus either spread within the vascular system of the plants or spread to other plant parts by spores. Flowers of 10 YST plants were also inoculated with P. igniaria isolated from leaves of previously inoculated plants. Disease developed in the flowers and flower parts of all inoculated plants, and the symptoms were identical to those observed when rosettes were inoculated and disease followed bolting and flowering. This fungus causes serious damage to YST plants and is a candidate biological control agent for YST control in the U.S.