|AL SA'DI, A.|
|AL MAQBALI, Y.|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/23/2007
Publication Date: 1/5/2007
Citation: Deadman, M.L., Al Sa'Di, A., Al Maqbali, Y., Klod, A., Aime, M.C. 2007. First report of Puccinia Triticina on Wheat in Oman. Plant Disease. 91:113.
Interpretive Summary: Rust fungi are a very large and diverse group of parasites that attack plants and annually cause billions of dollars of crop losses in the United States and throughout the world. This paper reports a rust fungus for the first time on wheat in the middle-eastern country of Oman. Knowledge of the distribution of plant pathogenic fungi is useful to agronomists and plant pathologists as well as plant regulatory and quarantine officials.
Technical Abstract: Wheat (Triticum aestivum L.) is an important crop in the Sultanate of Oman, cultivated both as a forage crop for livestock and for grain production. In April 2005, leaf samples of an unknown local variety showing rust symptoms were collected from Rustaq, 100 km south west of Muscat. Circular to oval, red-brown pustules occurred mostly on the upper surface of leaves on plants nearing maturity. The disease was widespread in many fields and was likely to be limiting to yield. Urediniospores typical of Puccinia triticina Erikss. (=P. recondita Rob. ex Desm. f.sp. tritici) were roughly subglobose, measuring 18-28 x 20-25 um, echinulate, with 3 to 8 scattered germ pores; teliospores 2-celled, 34-50 x 15-17 um, apex chestnut brown, lower cell light yellow, no germ pores (1,2). Pathogen identity was confirmed by nuclear ribosomal large subunit and internal transcribed spacer region-2 DNA analysis (voucher sequence deposited in GenBank, Accession No. DQ664194, voucher specimens deposited in the U.S. National Fungus Collections, BPI 872158 and 872159). Wheat is primarily grown during the winter months in Oman with harvests completed by May. Mechanisms for pathogen survival are not presently clear and current research is attempting to confirm the presence of the pathogen on alternate hosts, including grass weeds, and to determine the distribution of the pathogen on local land races and imported varieties of wheat. To the best of our knowledge this is the first documented report of P. triticina on wheat in Oman.