Author
KULECI, EBRU - Ondokuz Mayis University | |
TUNALI, BERNA - Ondokuz Mayis University | |
Berner, Dana | |
Cavin, Craig | |
Castlebury, Lisa |
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/15/2009 Publication Date: 8/1/2009 Citation: Kuleci, E., Tunali, B., Berner, D.K., Cavin, C.A., Castlebury, L.A. 2009. First report of leaf anthracnose caused by Phomopsis convolvuli on field bindweed in turkey. Plant Disease. 93:847. Interpretive Summary: Field bindweed is a troublesome perennial weed to many important crops in the world. In May of 2007, dying field bindweed plants were found along the edge of a wheat field between Bafra and Taflan, Turkey. Diseased leaves and stems were taken to Ondokuz Mayis University, Samsun, Turkey, and spores of a fungus were isolated from the diseased leaves. Stems and leaves of seven plants were spray-inoculated with an aqueous suspension of spores, and each plant was placed in a dew chamber in darkness and continuous dew. After 48 hours, plants from the dew chamber were moved to a greenhouse bench. Disease severity was evaluated 1 week after inoculation. Most plants were severely diseased. A culture of the fungus was sent to the Foreign Disease-Weed Science Research Unit, USDA, ARS, Ft. Detrick, MD for testing in quarantine. Morphology of the culture and spores and nuclear DNA sequences were consistent with that of Phomopsis convolvuli. DNA sequences were deposited in GenBank (Accession No. FJ710810), and a voucher specimen has been deposited with the U.S. National Fungus Collections. P. convolvuli has potential to be used for biological control of field bindweed, and, to our knowledge, this is only the second report in the world of leaf anthracnose on field bindweed caused by P. convolvuli. Technical Abstract: Field bindweed (Convolvulus arvensis L., Convolvulaceae) is a troublesome perennial weed in many important crops in the world. In May of 2007, dying field bindweed plants were found along the edge of a wheat field between Bafra and Taflan, Turkey. Disease lesions on leaves were irregular and variable in size, dark black in color, with a green margin. Severely diseased leaves were wilted or dead. Necrotic lesions were also present on stems, and completely dead stems were numerous. Diseased leaves and stems were taken to Ondokuz Mayis University, Samsun, Turkey. Diseased tissue was surface disinfested and placed on moist filter paper in Petri plates. Numerous pycnidia with alpha conidia were observed after 2 weeks. A fungus, designated 24-6, was isolated from the diseased leaves. Stems and leaves of seven plants at the 3- to 5-leaf stage were spray-inoculated with an aqueous suspension, plus 0.1 percent polysorbate 20, containing 10 million conidia per ml, and each plant was placed in a dew chamber at 24 degrees C in darkness and continuous dew. After 48 hours, plants from the dew chamber were moved to a greenhouse bench. Disease severity was evaluated 1 week after inoculation using a rating system based on a scale from 0 to 4. The average disease rating on inoculated plants was 3.75. Isolate 24-6, was re-isolated from all inoculated plants. An axenic culture was sent to the Foreign Disease-Weed Science Research Unit, USDA, ARS, Ft. Detrick, MD for testing in quarantine. Alpha conidia from pycnidia on inoculated plants were bi-guttulate, one-celled, hyaline, nonseptate, oblong to ellipsoid, and 7.0 to 12.8 × 3.0 to 5.5 microns (mean 10.0 × 3.9 microns). Morphology was consistent with that of Phomopsis convolvuli Ormeno-Nunez, Reeleder & A. K. Watson. Comparison of ITS 1 and 2 sequences with available sequences of a vouchered Phomopsis convolvuli specimen (GenBank U11363 and U11417, BPI 748009) showed 192 of 193 identities for ITS1 and 176 of 179 identities for ITS2. Nucleotide sequences for the ribosomal ITS regions (ITS 1 and 2) were deposited in GenBank (Accession No. FJ710810), and a voucher specimen has been deposited with the U.S. National Fungus Collections. P. convolvuli has potential to be used for biological control of field bindweed, and, to our knowledge, this is only the second report in the world of leaf anthracnose on field bindweed caused by P. convolvuli. |