|GEBREMARIAM, E - Ankara University Of Turkey|
|KARAKAYA, A - Ankara University Of Turkey|
|ERGINBAS-ORAKCI, G - International Maize & Wheat Improvement Center (CIMMYT)|
|DABABAT, A - International Maize & Wheat Improvement Center (CIMMYT)|
|SHARMA-POUDYAL, D - Washington State University|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/24/2015
Publication Date: 1/1/2016
Citation: Gebremariam, E.S., Karakaya, A., Erginbas-Orakci, G., Dababat, A.A., Sharma-Poudyal, D., Paulitz, T.C. 2016. First report of Fusarium hostae causing crown rot of wheat (Triticum spp.) in Turkey. Plant Disease. 100:216.
Interpretive Summary: A survey was conducted in summer, 2013 to identify Fusarium spp. associated with wheat crown rot in Turkey. Symptomatic crowns and lower stems from bread and durum wheat were plated out, fungi isolated, and identified with morphological and molecular techniques. They were tested for pathogenicity on wheat in greenhouse trials. Fusarium hostae was identified in the collections, and found to be mildly pathogenic. This is the first report of F. hostae on wheat in Turkey, although it has also been found to cause disease on Hosta and Hyacinth spp., and is closely related to F. redolens.
Technical Abstract: Crown rot disease of wheat is caused by a complex of Fusarium species. To identify species associated with crown rot in Turkey, crowns and stems of bread wheat (Triticum aestivum L.) and durum wheat (T. durum Desf.) were collected from the Central and Southeast Anatolia, Black Sea, Aegean, Mediterranean, and Eastern Anatolia regions in summer 2013. Crown and stem pieces were surface-disinfested with 1% sodium hypochlorite solution for 3 min., rinsed three times in sterile distilled water and dried on sterile filter paper. Sections were placed on peptone PCNB agar, a selective medium for Fusarium isolation and then transferred to SynthetischerNährstoffarmer Agar (SNA) (Leslie and Summerell, 2006). Single conidia were isolated, and monosporic Fusarium sp. cultures were identified as F. hostae by sequencing the translation elongation factor 1 alpha (TEF-1a) gene region using ef1 (5’-ATGGGTAAGGARGACAAGAC-3’) and ef2 (5’-GGARGTACCAGTSATCATG-3’) primers (O’Donnell et al. 1998). The TEF gene sequences were analyzed with the NCBI GenBank database. Twenty isolates had a 99% match with accessions of F. hostae (eg. DQ854862). F. hostae isolates were tested for their pathogenicity on susceptible durum wheat (T. durum) variety Kiziltan. Plastic tubes (2.5 cm in diameter and 16 cm in height) were filled with sterile sand, soil, and peat mixture (50:40:10,v:v). A PDA plug (1-cm diam.) was taken from the margin of a 7-day-old culture and placed in the tube. A single pregerminated seed was placed on the PDA plug and covered with soil mix. A sterile agar plug was used as a control treatment. Each treatment was replicated 3 times, and the experiment was repeated to confirm the results. Scoring for disease severity was carried out nine weeks after inoculation, using a 1-5 scale (1: 1-9%, 2: 10-29%, 3: 30-69%, 4:70-89%, 5: 90-99%) modified from Wildermuth and McNamara (1994). Scores ranged from 1 to 3 with an average of 2.3. The scores of seven isolates were significantly greater than the non-inoculated control, and six isolates had scores of 3.0. Necrosis was observed on crowns of treated plants, while control treatments showed no necrotic symptoms. Re-isolation was carried out from crowns of inoculated plants and control plants. The re-isolated cultures were confirmed as F. hostae by comparing their morphology with known cultures of F. hostae and no culture growth was observed from control plants. To our knowledge, this is first report of F. hostae causing crown rot on wheat in Turkey. F. hostae was first isolated from Hosta sp. in the U.S. (Geiser et al. 2001). F. hostae is closely related to F. redolens and has also been reported on Hyacinth sp. in the Netherlands (Baayan et al. 2001).