| Autor: |
Rooney-Latham S; a Plant Pest Diagnostics Center , California Department of Food and Agriculture , Sacramento , California 95832., Lutz M; b Plant Evolutionary Ecology, Institute of Evolution and Ecology , University of Tübingen , Auf der Morgenstelle 5, D- 72076 Tübingen , Germany., Blomquist CL; a Plant Pest Diagnostics Center , California Department of Food and Agriculture , Sacramento , California 95832., Romberg MK; c National Identification Services , United States Department of Agriculture Animal Plant Health Inspection Service , Beltsville , Maryland 20705., Scheck HJ; d California Department of Food and Agriculture , Santa Barbara , California 93110., Piątek M; e Department of Mycology , W. Szafer Institute of Botany, Polish Academy of Sciences , Lubicz 46, PL-31-512 Kraków , Poland. |
| Abstrakt: |
White leaf smut is a minor foliar disease of sunflower (Helianthus annuus) in the United States. The disease occurs primarily in greenhouse-grown sunflowers in California and causes leaf spot, defoliation, and a reduction in yield and crop value. Historically, many Entyloma specimens with similar morphological characters, but infecting diverse plant genera including Helianthus, were called Entyloma polysporum. Recent comparative morphological and molecular work has shown that Entyloma species infect hosts within a single genus or species, suggesting that the sunflower Entyloma species may not be E. polysporum. In 2015, sunflower leaf smut material was collected from ornamental sunflowers in a greenhouse in Santa Barbara County, California. Morphologically, this species differed from E. polysporum in having smaller, more regular-shaped teliospores and prominently developed conidiophores with cylindrical conidia. The rDNA ITS1-5.8S-ITS2 (internal transcribed spacer [ITS]) region of the sunflower leaf smut was phylogenetically distinct from all previously sequenced Entyloma species and found only on H. annuus. This study confirms that the sunflower leaf smut pathogen represents a novel species, Entyloma helianthi. Possible misidentification of the anamorphic stage of Entyloma helianthi as another leaf spot pathogen, Ramularia helianthi, is also discussed. |
