Hirschfeldia incana, a new host report for white blister caused by Albugo candida in Turkey

Hirschfeldia incana is a common plant of waste ground in Turkey and is widespread in different continents of the world. Its leaves and seeds are edible and it is also cultivated for bees to increase honey production. During surveys in late spring of 2007 in the Şanlıurfa district of the south-eastern Anatolia region in Turkey, typical and severe symptoms of white blister disease were observed on plants of H. incana. Infection was generally localised on some branches of plants. Infected branches and buds were hyperplasic, being ~3–4 times thicker than healthy ones. The pustules were white. Sori were common on branches, mostly coalescent (Fig. 1), individual sori rarely being found, and measuring 0.5–1.2 × 1–4 mm in diameter. Sori were mostly circular, ellipsoidal or irregular shapes and formed blisters up to 3 mm in height. Approximately 80–90% of the infected branches were covered with these sori. Sporangia were more or less spherical and hyaline, uncommonly punctuate on the surface and measured 13–24 µm in diameter. Sporangiophores were hyaline and 16–25 × 27–48 µm with many being narrow at the base and broadening to the apex. Based on macroscopic and microscopic characters, and the host being in the Brassicaceae, the pathogen on H. incana was identified as Albugo candida (Glawe et al. 2004). Albugo candida has been reported on other species in the Brassicaceae in recent years (Koike 1996; Jacobson et al. 1998; Zapata et al. 2005). To our knowledge, this is the first report of a white blister disease caused by A. candida on this host in Turkey. A specimen has been lodged in the Herbarium of the Agricultural Faculty of Harran University.

Fig. 1.  Sori symptoms of A. candida on branch and buds of Hirschfeldia incana.