First record of leaf rust caused by Puccinia hordei on Hordeum vulgare ssp. spontaneum in Turkey

In spring 2003, a leaf rust caused by Puccinia hordei was found on a wild barley species, Hordeum vulgare ssp. spontaneum (HVS), in the Sanliurfa province, south-eastern Anatolia District. Uredinia occurred on the upper leaf surfaces, leaf sheaths and occasionally the lower leaf surfaces. These sori were commonly 0.1–0.4 mm across, oval to round and light brown in colour. Low numbers were seen on the flag leaf, progressively increasing on older, lower leaves. Urediniospores were egg-shaped to spherical, yellow and 28–36 by 24–28 µm. Telia commonly occurred on the lower surface of older leaves and usually contained two-celled and occasionally one-celled mesospores. These features were used to identify Puccinia hordei, the cause of brown leaf rust. Freshly harvested urediniospores were used to prepare a spore suspension, adjusted to 4 × 105 spores mL−1 with 5 g of talcum powder/mL. This suspension was sprayed onto 20-day-old seedlings of HVS (two leaf stage), which were then put into a moist chamber maintained at around 100% relative humidity for 16 h at 20 ± 1°C. After this period, the chamber was then partially opened and plants allowed to dry slowly, before moving them into a glasshouse at 22 ± 1°C. Similar treatments were performed on control plants, sprayed with sterile water only. Lesions similar to those observed in the field occurred within 2 weeks on the plants sprayed with the spore suspension. The control plants remained healthy. Puccinia hordei occurs widely on HVS in Israel (Manisterski et al., 1986; Manisterski & Anikster, 1994) and successful artificial infections have been achieved (Moseman et al., 1990). This is, however, the first record of brown leaf rust on HVS as a wild host in Turkey, where P. hordei occurs occasionally on cultivated barley in coastal districts (Karaca, 1965). This record is significant in the search for natural sources of resistance to a disease which causes widespread losses to cultivated barley (H. vulgare) worldwide.