1. Dep. of Agronomy and Horticulture Univ. of Nebraska‐Lincoln 202 Keim Hall Lincoln NE 68583‐0915 USA
2. Dep. of Plant Pathology Univ. of Nebraska‐Lincoln 406 Plant Sciences Hall Lincoln NE 68583‐0915 USA
3. Jilin Agricultural Univ. Changchun Jilin 130118 PR China