The diversity of fungi colonizing necrotic inflorescence buds of rhododendron (Rhododendron L.)

Małgorzata Żołna, Barbara Kierpiec-Baran, Maria Kowalik

Abstract


The infection of rhododendron (Rhododendron L.) inflorescence buds caused by pathogenic fungi induces its browning, withering, and dieback. The identification of fungi causing the infection of rhododendron inflorescence buds can be a reason for creating new improved cultivars with genetically determined resistance to pathogens. The investigations were carried out in 2010–2011 on the collection of ornamental plants of the Faculty of Horticulture, University of Agriculture in Kraków. The material comprised infected inflorescence buds collected from nine newly bred taxa and one botanical species of rhododendron. 596 colonies of fungi belonging to 31 species were isolated from infected rhododendron inflorescence buds. The dominant species were: Pestalotiopsis sydowiana, Truncatella truncata, Alternaria alternata, Phialophora asteris, and Trichoderma viride, which constituted almost 74% of the isolated fungi population. Boeremia exigua var. exigua, Epicoccum nigrum, Fusarium poae, Mammaria echinobotryoides, Paraphoma chrysanthemicola, Phialophora cyclaminis, Phoma eupyrena, Talaromyces wortmannii, Umbelopsis isabellina, and other fungi were isolated in a lower number.

The results of mycological analysis confirm the diversity of species colonizing necrotic inflorescence buds of rhododendron.

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Keywords


Rhododendron; inflorescence buds; dieback; pathogenic fungi

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References


Czekalski M., Frużyńska-Jóźwiak D. 1995. Obumieranie pąków kwiatostanowych różaneczników wywoływane przez grzyb Pycnostysanus azaleae (Pech) Mason. / Flower bud blast caused by the fungus Pycnostysanus azaleae (Pech) Mason. Erica Polonica, 6: 7–14. (in Polish)

Domsch K.H., Gams W., Anderson T.H. 1980. Compendium of Soil Fungi. Acad. Press. London, New York, Toronto, Sydney, San Francisco, 859 pp.

Ellis M.B., Ellis J.P. 1987. Microfungi on Land Plants. An Identification Handbook. Croom Helm. London, Sydney, 818

Frużyńska-Jóźwiak D., Werner M. 2000. Grzyby wyniszczające pąki i kwiatostany różanecznika. / Fungi destroying buds and inflorescences of rhododendron. Ochrona Roślin, 3: 37–38. (in Polish)

Garibaldi A., Gilardi G., Bertetti D., Gullino M.L. 2002. First report of Pycnostysanus azaleae on Rhododendron in Italy. The American Phytopathological Soc. 86 (5): 560.

Glawe D.A., Hummel R.L. 2006. New North American host records for Seifertia azaleae, cause of Rhododendron bud blight disease. Pacific Northwest Fungi, 1 (5) 1–6.

Guba E.F. 1961. Monograph of Monochaetia and Pestalotia. Harvard Univ. Press, Cambridge, 255 pp.

Index Fungorum. On line www.indexfungorum.org.names/Names.asp, accessed on 10.10.2012.

Kirk P.M., Cannon P.F., Minter D.W., Stalpers J.A. 2008. Ainswort & Bisby’s Dictionary of the Fungi. CAB International, Wallingford, UK.

Kowalik M. 1993. Grzyby gleby inicjalnej industroziemnej rekultywowanego w kierunku rolnym i leśnym zwałowiska Kopalni siarki „Machów”. Zesz. Nauk. Akademii Rolniczej im. H. Kołłątaja w Krakowie. Rozprawa hab. 180, 78 pp. (in Polish)

Kowalik M. 2008. Fungi and fungi-like Oomycetes isolated from affected leaves of rhododendron. Acta Mycol. 43 (1): 21–27.

Kowalik M. 2009. Bioróżnorodność grzybów występujących w fyllosferze różanecznika zimozielonego Rhododendron L. / Biodiversity of fungi occurring in phyllosphere of evergreen rhododendron Rhododendrons L. Zesz. Probl. Post. Nauk Roln. 539: 341–348. (in Polish)

Kowalik M., Kierpiec B., Bonio J., Żołna M. 2011. Fungi inhabiting spots and necroses on the leaves of azaleas (Rhododendron L.) in the Botanical Garden of the Jagiellonian University. Phytophatologia, 62: 41–48.

Kowalik M., Muras P., Żołna M., Kierpiec B. 2010. Grzyby wyosobnione z nekrotycznych plam na liściach różaneczników zawsze zielonych Rhododendron L. / Fungi isolated from necrotic spots on the leaves of evergreen rhododendrons Rhododendrons L. Zesz. Probl. Post. Nauk Roln. 554: 49–55. (in Polish)

Kowalik M., Żołna M., Kierpiec B. 2012. Fungi living at the fallen leaves of rhododendron and azalea (Rhododendron L.). Acta Sci. Pol. Hortorum Cultus, 11 (2): 161–166.

Kryczyński S., Weber Z. (ed). 2010. Fitopatologia, t.1., Podstawy Fitopatologii, 639 pp. (in Polish)

Płażek A. 2011. Patofizjologia Roślin. Wydawnictwo Uniwersytetu Rolniczego w Krakowie, 140 pp. (in Polish)

Rifai M.A. 1987. A revision of the genus Trichoderma. Mycol. Papers, 116: 1–56.

Stark Ch. 1985. Das Rhododendron-Knospensterben. Rhododendron immergrüne Laubgehölze Jahrb.: 76–79. (in German)

Stark Ch. 1994. Das Rhododendron-Knospensterben. [In:] Offizieller Katalog Rhodo’94. Plois, Westerstede: 45–49. (in German)

Werner M., Czekalski M., Frużyńska-Jóźwiak D. 1996. Plamistość płatków kwiatowych różaneczników w Polsce. / Petal blight on rhododendrons in Poland. Erica Polonica, 7: 52–55. (in Polish)

Werner M., Frużyńska-Jóźwiak D., Czekalski M. 1998. Analiza mikologiczna nie rozkwitających kwiatostanów różaneczników. / Mycological analysis of rhododendron inflorescences that fail to open. Erica Polonica, 9: 60–63. (in Polish)