First report of Ustilago avenae causing loose smut of oat (Avena sativa) in Shandong China.
Oat (Avena sativa) is an important annual forage grass that is increasingly grown in many regions of China. In late May and early June of 2017, a smut disease was found on oat at the research station of Qingdao Agricultural University in Shandong province. The panicle was entirely destroyed except for the rachilla and glume, spores, olive-black in mass, appeared in all spikes of a panicle in place of seeds, forming powdery masses, similarly to the symptoms caused by loose smut. Teliospores were irregularly globose to subglobose and reddish brown. Occasionally, elongated teliospores were also observed. Based on morphological characteristics and molecular data (sequence analysis of part of the nuclear ribosomal internal transcribed spacer region), the causal agent was identified as Ustilago avenae. This fungus has been reported from multiple locations in China, including Shanxi, Hebei, Jiangsu, Gansu, Henan and Heilongjiang. This is thought to be the first report of U. avenae causing loose smut on oat in Shandong.